B.A.R.GT684

GOVERNMENT OF INDIAATOMIC ENERGY COMMISSION

SPECTROSCOPY DIVISIONANNUAL PROGRESS REPORT FOR 1972-73

Edited by

V. B. Kartha and N. A. MarasimhamSpectroscopy Division

BHABHA ATOMIC RESEARCH CENTRE

BOMBAY, INDIA1973

B . A . R . 0 . - 6 8 4

GOVERNMENT OF INDIAATOMIC ENERGY COMMISSION

CO

fit

S1BCTR0SC0PI DIVISICJSANHUAI IROGRESS REPORT FOR 19?2 -73

Edited by

V.B. Kartha and N.A. NarasinihamSpectroscopy DiriBion

BHABHA ATOMIC RESEARCH CENTREBOMBAY, INDIA

1973

O O B T E H T S

1 . ANALYSIS 0 7 HIGl'PURITY AHD REACTOR GRADE MATERIALS 4

(a) Emission Spectroacopy 6

(b) X-ray Pluoreecenee 31

(o) Atonic Absorption Spectrophotometry 45

(d) Infrared and Hainan Speotroscopy 46

(«) Ieotopic Analysis 47

(f) Analysis of GaBes In Metals AS

I X . ATOMIC, MOLECULAR AND SOLID STATE SPECTROSCOPY 54

(a) Hyperfine Structure and Isotope Shift Studies in 56Atomic Spectra

(b) Spectra of rare-earth ions in crystals 6 2

(c) Solid-State Spectra (Lumlniecence) r

(d) Electronic Spectra and Structure of Free TCRadicals and Simple Molecules

(e) Tibrational Spectra and Molecular Stricture ^

I I I . OPTICS

I t . SERVICE ELECTRONICS

APPENDIX I - Spectrochendcal Methods Developed I sSpectroacopy Division.

APPENDIX U *. Participation In Symposia, Conferences 157and Simmer Schools.

APPENDIX III - Post-Graduate Teaching, Research and *59Training to Outside Personnel.

APPENDIX IY - List of Papers Published in Journals/ 1 6 1

Submitted for Publication.Papers Presented at the Conference/Symposia.BAfiC Reports Produced.

APPEUD1X V - Service Analysis and Desigi and Pabrica- 167tion of Optical Equipment to Obits ofDAE and other Institutions.

Spectroeoopy has .Jpeyjed an important role in the development of

Science and Technology. As an analytical tool, i t has several important

applications in reactor technology* Its main advantage i s that i t i s

quick and can estimate very low concentrations of a number of elements

simultaneously. Requiring, as i t does, only minute quantities of samples

and permitting a statistical and repeatable approach, i t i s in several

cases superior to the usual conventional ohemical methods of analysis,

particularly for determinations of trace quantities of undesirable impu-

rities in reaotor materials during various stages of their production.

Optical speotrosoopy provides the only method of quantitative analysie of

individual rare-earths. X-ray end optical fluorescence methods are uBeful

for non-destructive quantitative analysis of several Important materials

and finished products. Spedtroscopy i s also one of the most important

diagnostic tools for the investigation of several problems of importance

to astrophysics, plasma physios etc. Being essentially an unperturning

probe whioh samples the system in space and time, i t i s a unique multi-

purpose tool. Realising, therefore, i t s usefulness, Spectrosoopy

Laboratory has been organised to serve primarily the analytical needs of

the atomic energy programmes. Everyone of the scientists i s trained in

th* Bpeotroohemioal methods of analysis so that he can share the analytical

responsibility of the dlvii^cn ead at the sane time contribute effectively

to further development of analytical methods,,

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Baaic reseaxoh In spectrosoopy i s important and the division

undertakes research in atomic, molecular and solid state spectrosoopy.

Severel senior soientists work on some select problems in eaoh of the

above areas of research Kith the oo-operation of junior scientists.

For several speotroscopio investigations, i t is necessary to

have instruments using optics of high quality and precision. The

Speotrosoopy Laboratory has, therefore, undertaken the preparation of

high quality optical components like Fabry-Perot flats, lens systems,

large spherical surfaces etc. with which high resolution interferometers

and speotrographs of large light gathering power can be built*

ELeotronics also plays a vital role in the building-up of instru-

ments of high sensitivity and resolution. Coupled with high precision

optics, eleotronics provides sensitive methods of recording spectra of

free radicals whose lifetimes are a few microseconds or less . Recording

Fabry-Perot spectrometers (REFPOS), Flash Photolysis and flash discharge

units are fabricated for use in the high resolution studies of atomic and

moleoular spectra* Recent innovations in speotroeoopio techniques like

Fourier Transform Speotrosoopy, modulation Speotroscopy and Saturation

(Lamb Dip) Speotroscopy illustrate the Importance of electronics and

optics in spectroscopic investigations. The division i s engaged in

making use of some of the above techniques for high resolution speotrosoopy.

With these objectives in view end to achieve a satisfactory

progress in the above areas of research, the Spectroscopy Laboratory i s

organised into the following sections. These sections not only serve the

- 3 -

analytical needs but also undertake researoh in atom'o and molecular

speotrosoopy and in optios.

I . Analysis of High Furity and Beactor Grade Materials

l i t Atomlot ISoleoular and Solid State Speotrosoopy

III. Optics

IV. Service ELectroniea

The work carried out during the year 1972-73 in each of the

seotion is described in the Report.

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I . ANALYSIS OF HIGH PURITY AND REACTOR GRADE MATERIALS

High purity materials and in particular those used in reactor

and 8emioonduotor technology, require s e n s i t i v e , accurate and r e l i a b l e

methods of analys i s to t ea t the ir purity at various stages of the i r

production* Analysis of these materials i s an e s sent ia l service and

i s provided by the Spectroscopy Division to the various projects of

BARO and other uni t s of DAS* Several speotroohemioal methods have been

established and used routinely for uranium, thorium and other mater ia l s |

however, with the increase in the a c t i v i t i e s of the Research Centre,

several new projects are undertaken and these require the development

of new techniques for achieving lower l i m i t s of deteotion in respeot of

oertain ' s ens i t i ve 1 elements in materials of importance.

X-ray Fluoresoenoe technique has been inoluded to aid the

Electrochemical analyt ical service and through i t a inoluaion, i t has

been possible not ?nly to provide a quiok and s e n s i t i v e method of non-

destructive analys is of several materials but a l s o to reduce the

consumption of photographic p l a t e s and eleotrodes whioh involve expenditure

in foreign exchange*

In a l l more than 50 speotroohemioal analyt ical methods have been

developed during the year and these inolude Emission Spectrographie Methods

(ESM) employing an aro/spark exc i tat ion source for excit ing the oharaotetiB-

t i o spectra of the elements, X-ray Exoited Optical Iluorescenoe (XSRP) and

X-ray Fluoresoenoe (XRF) methods whioh are described in th i s sect ion*

A oonsolldated l i s t of a l l the analyt ical methods developed in the diviBion

t i l l now i s given in Appendix I .

Ta AEALYSIS OS HIGH HTRIfY & REACTS GRABS

fst) SoecfcrcacoTJT (b) Z-ray Fluorescence SDectroscoxor

Dr. 7 .B . KarthaDr. Hahavir SinghDr. 7.A. JobD r . (5 . T<fdcffhi7r<"°•'•"jyaraDr. MJT. 3 i x i t

T.B. SaranathanP.S . 7 , GrampurohitDr. 0 . KrishnamurtySr. J .Dr. B.M. Dix i tL.C. Chandola*Dr. B.C. NaikB.B. YengsarkarO.L. Bhale*N.D. PatelSmt. Romola D'CunhaDr. 7.A. Saxma

7.P.H.P.

BellaryKaranjikar

DCCC0C

SD2SD2SD2SD2SD2SD2SD2SD2SD2SD2SD2B

SC2SC2SC2SC2

i J . Eanat

Smt. P.M. Hajarao*K. ISmt. S .3 . Kartha*Smt. MoA. 7aze*Kum. Shei la Gopal*Smt. Haghuveer*

S.M. MarathaI . J . MaohadoB.7 . SubrsmanianA.S. Prakasa BaoSmt. 7 . UahajanSmt. 7 . S . Dixi tKum. If. SaraawathyM.D. SaksenaOomman ThomasKum. K.J. Annamma7.1T.P. KaimalS. KriabnanKum. P, Rugminl BaiKum. T.S. SugandM

Those marked * and ® part ic ipate in research work onElectronic Speotra & Structure of Free Radicals and SiapleMolecules and Vibrational Spectra it 2£oleoular Structure withthe senior s c i e n t i s t s under I l ( d ) and (e) respect ive ly .

H.M. AgrawalDr. E.M. DixLt

P.P. KhannaSmt. A.H. MobileS.K. KapurSmt. S.S. DeahpandeS.K. Ualhotra

(o) Atomic Absorption Spectrophotometry

S.7. GrampurohitDr. M.N. Dixit

SD2C

(d) Infrared and Bang" Spontrosoopy

Dr. 7 .B . Kartha DN.D. Patel SD2Smt. Romola U*Cunha0 BDr. 7.A. Sarma SC2G.S. Ghodgaonkar© SC27 . P . Beliarya

Ce) Isotopic

Dr. G.D. Saksena SES.A. Ahmad SD2A. Venugopalan SA(B)

(f) Analysis of Gases in Metals

P.K. VlahiS.S» Biswas

BSC2

I(a) TEMTSSTfiw SPE0TR03CQPY

1* Empirical Evaluation of Speotrochemioal MethodB

(G. Krishnamurty and V.B. Kartha)

The reproduoibility of a spectrographio method depends on

several faotors l ike exoitation condition, selection of internal

standards, acourate intensity meaeuremanta ete» With a view to assess

the errors associated with these various steps, an Investigation of the

carrier d i s t i l la t ion method for estimation of impurities in U_0 was3 8

undertaken. To estimate errors in intensity measurements, intensity of

impurity lines in the same spectra were measured repeatedly. An average

standard deviation of 10$ was found to be present in measurements using

a non-recording- microphotometer. This error could be reduced by uBing

recording instruments,

A computer programme was written for plate calibration and

intensity calculations. Using this programme it was shown that the usual

value of 0.5 used for Kaiser oonstant in straightening plate calibration

curve is not the best value always. It was shown that the Kaiser oonstant

is quite sensitive to (i) the intensities of the iron line steps and (ii)

the region of the plate. When care is taken to use iron lines of more or

less same intensity the Kaiser oonstant varied only by about 20$ and the

slope of the plats oaliteration line was found to be reproducible within

%-%• Ihe Kaiser constant was found to vary from a value of about 0.3

at 2500 A to 0.7 at 2900 A. These results show that reproduoibility of

analytical results could be improved by proper choice of plate oalibration

lines.

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2* BMOtroggftPhlo Determination of thirty Impurities la Hign-PuritvT h o r i a ~ " ~ "

(P.8, Ibrty, 8.7. Grampurohit, M.D, Saksena, Y.N.P.Kaimal and S.K. Kapoor)

High purity thorium i s required as fer t i l e material in nuclear

reactors and i t i s necessary to analyse the thorium for a large number

of Impurities at low concentrations* A spectrographic method has bean

developed for this purpose* The analysis i s oarried put in three parts

and the details ere given below*

For the 16 impurities B. Be, Cd, 11, Co, Cr, Cu, Fe, Kg, tb ,

Hi, Pb, 3b, Sn, P and Si a carrier dist i l lat ion method i s used with

AgCl carrier and GagO internal standard. Speotra are excited at

10 snips d.o. After a prearc time of 5 seconds speotra are photographed

for 35 seoonds on a Hilger large quartz speotrograph in the regiona

2200-2850 A, using SA-1 ennlsion. Using both si lver and gallium

internal standard l ines , the ranges of analysis are as follows.

B, Be, Cd t 0*1-2.0 ppn

Al,CofCrfCa,Pe,lfc, i . U2O rt

Ha, Ni,Pb,Sb,£fa 5

i», Zr, Si t 50-1000 "

For the nine Impurities Ag, Oa, Bl. Ti, 7 , Ca, Mb, Zn and 2r,

a method i s used with Afi VaF as carrier and Oe ag internal standard.

Speotra are exoit«k with 15 smps d.e . arc, and recorded using R-40

eeulAion on the Jarrel Ash 5*4 neter Bbert grating speotrograph equipped

with a 1200 grooves/no grating blazed at 3300 A. The concentration

ranges of the impurities are given below.

- 8 -

Ag, 6a I 0.1-2.0 ppm

M, Tif Y I 1.0-20 "

Ca, Mb, Zn, 2r i 10-200 "

For analysis of alkali and alkaline earth impurities, a carrier

distillation technique i s employed with AgCl carrier and Ga and Sc

internal standards. Speotra are excited at 10 amps d.o. in an oxygen

atmosphere using a Stalwood jet , end reoorded on the Hilger glass

speotrograph. By using the Stalwood jet and employing an aperture at

the oollimating lens the high back-ground oontinuum in the 4000-8000 A

region employed for this analysis, could ba removed. This, combined

with pre-arcing of the eleotrodes for removal of traoe sodium present

in them, has made i t possible to go down to low limits for these

impurities.

6a, Li t 1-20 ppm

Na t 5-100 "

K i 10-200 "

3, Spectrochemioal Determination of Rare Earths in Uranium

(S.V. Grampurohit, V.N.P. Kaimal and P. Hugmini Bai)

Present method for the determination of rare earths in nuolear

purity uranium involves preconeentration of the rare earths in a

laDthanum oxide matrix from 50 gms of uranium and speotrographio analysis

of the lanthanum oxide* The method i s time-oonsuming and cumbersome

and slows down the production of high-purity uranium.

A sensitive speotrographio method requiring mueh l e s s time I s ,

therefore, being developed in our laboratories.,

Gd 3350-48 A

FIG. 1. SPECTRA OF GADOLINIUM IMPURITY INDIFFERENT MATRICES.A. 0-05/ ON ELECTRODE-GRAPHITE MATRIX(5% N Q F ) .

B. 1 0 * ON ELECTRODE-LQ2O3* GRAPHITEMATRIX (V-5).

- 9 -

In the preconcentration-cum-spectrographio analysis, the

detection limits are about 0 .5^ of Gd and 2.5 i of Ce on the electrodes.

After detailed investigations regarding method of excitation i t i s found

that much lower detection limits could be reached (O.OIf for Gd and O.Hf

far Ce), i f the rare-earths are concentrated on graphite and exoited with

a 5°/> NaF carrier, at 15 amps d.c. A comparison of the spectra obtained

under the two conditions are shown in Fig. 1. With this new method the

amount of uranium has been reduced from 50 gms to 2 gms for preooncentration

purpose.

Investigations of several extraction methods showed that the rare

earths can be freed from uranium oomplAtely by TUP extraction in nitrio

acid medium. Since calcium or iron interfered (depending on the line

chosen) with Gd estimation, removal of calcium i s effected through

extraction by oxine in ohloroform. The combined chloroform extracts are

dried on graphite and analysed. Because of the small amounts of uranium

involved, extraction and spectrographio analysis take a auoh shorter time

in the present method.

4* Spectrographio Determination of Boron in UF.

(P.S. Murty, S.M. Marathe and P. Rugmini Bai)

In the production of nuclear grade uranium, i t ia necessary to

check the BF, for boron contamination. A speotrographio method for this4

determination i s being developed. The method involves mixing the UF^ sample

with NaF (5#) and burning 200 mg of this mixture in a d.o. arc at 5 amps.

The spectra are recorded for 15 seconds on a Hilger large quartz spectrograph

in the 2200-2830 A region. Using the boron l ine at 24S7.7 A, a sensitivity

-10-

of 0.2 ppm has been obtained. Further work i s in progress to determine

the accuracy of the method and checking recovery.

5. Direct 5pectroftraphic Analysis of Arsenic Metal and Oxide

(P.S. Murty, S.M. Marathe, S.K* Kapoor and M. Saraswathy)

Spectrographio methods ueing d.c. arc excitation has been

developed for the estimation of traoe impurities like Co, Sb, Mh, Pb,

etc. in Aa-metal and A s o 0 . The sample (As or AsO ) i s mixed with pure2 3 2 5

graphite powder in the ratio 1>1 by weight and 20 tag of the mixture i s

arced at 10 amp d.c. The spectra of sample and synthetic standards

(prepared on As base or As_0 base) are recorded on a JACO 3.4 meter

Ebert plane grating spectrograph. A grating with 30,000 l ines per inch

blazed at 3300 A i s employed in the f irst order (dispersion 2.5 A/mm).

The detection limits for the different elements are as follows!

Co, Mh, Pb,

3b,

Cr,

Al,

Cd,

Ni, Bi

Cu . .

%

2n

1

5

20

50

ppm

11

n

11

6. SpectaroKraphlc An.al.V9is of High Purity Antimony

(P.S. Marty, S.M. Marathe, S.K. Kapoor and M. Saraswathy)

A d.c. arc spectrographic method has been developed to determine

seventeen trace impurities like B, As, Pb, Sn eto. in high purity Sb.

The EKitvple i s mixed with pure graphite powder in the ratio 1011 by weight

and 50 ing of the mixture i s excited at 10 amp d.c. in oxygen atmosphere

using the Stalwuod jet assembly. Synthetic standards are prepared on Sb

basis (spec-pure). The speotra are recorded on a Jarrell-Aah Ebert

- 1 1 -

3.4 metur plane ^-mting ap«ctro£ruph. A gratbie with 30,000 ] i.non pura

inch biased at 3300 A in f i rs t or-Jor ir employed in thi> region T'Oi:--o

3450 A. 500 ppm of chromium (as oxide) is incorporated as int'-rr.-ii

standard in the graphite powder which ia further mixed with the . . .0 0 e

sample or standard. The Cr lines at 2677 A, 2835 A and 3021 A serve

as internal standard lines for the various elements. A two step

fi l ter with 100 and 10 percent transmissions is used in front of the

spectrograph s l i t while photographing sample and standard spectra in

order to measure optical densities in the suitable step for the

impurity elements. The detection limit range from 0.1-10 ppm, with

average standard deviation of 10-20/J.

7. Spectroftraphio Analysis of Hiffh Purity Tantalum Oxide

(L.C. Chandoia, R. Venkatasubramanian and V.3. Dixit)

Two spectrographic methods have been developed to determine

Nb and eleven othe^ trace impurities in high purity tantalum oxide. Tho

methods are (a) an intermittent a.c. arc method, and (b) a d.c. ere

method. In method (a) , the sample is glued to the flat tops of a pair

of graphite electrodes and excited by a Hilger's low voltage

intermittent a.o. arc source at 6 amp, current. In method (b), the

sample i s mixed with zinc oxide and graphite in the ratio 111 *1 and

excited in a d.o. arc at 15 amps current in the cup of a graphite

electrode using a pointed counter electrode. In both the methods,

the spectra are photographed on a JACO 3*4 meter crating spectro^raph»

using the first order of a 1200 grooves/mm grating blazed at 33 M A

in the region 2300-3500 A. Niobium cem be estimated to a lower limit

of 40 ppm by the a.c arc method and 130 ppm by the dcc arc method.

- 1 2 -

elements estimated simultaneously axe Al, Fe, Pb, Mh, Mo, Ni, Si,

Si, Ti, V end 2r. The precision of intermittent a.o arc method was

found to be + 12?S while that of d.o arc method + 21$. The d.o. arc

method serves as an alternative method in oase of a low voltage a.c.

arc source i s not available.

0* Speotrographio Determination of Peace Impurities in Magnesium Metal

(G. Krishnamurty, Sheile Oopal end S. Krishr.an)f.

An emission speotrograpMo method for the quantitative

estimation of seventeen trace Impurities in magnesium metal has been

developed* High purity magnesium i s used as a reducing agent in the

process of converting zirconium tetrachloride to zirconium metal and

also uranium fluoride into uranium metal in the nuclear technology.t

Besides tola , magnesium has wide industrial applications. Hence the

estimation of trace impurities in magnesium metal i s necessary and

emission speotroacopy i s found to be quite suitable for th i s purpose.

In the present method the magnesium metal i s converted into

magnesium oxide by directly heating the raetnl in an alumina crucible at

500 C for 2-.J hours.

The magnesium oxide i s mixed with 2?S of a carrier mixture

containing pure sodium fluoride and internal standard gallium. 30 rag

of the charge i s excited using 100 L type Graphite electrodes at 10 amp

in a d.o. arc. The exposure time of 20 seconds was fixed from

volatilisation studies of the various elements. Spectra are recordede

on Hilger large quartz speotrograph in the wavelength region 2410-3360 A

using Ilford N-50 emulsion, Ga line at 2659.B6 A i s used as the

internal standard.

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The impurities determinad and their ranges are given below!

Be,Hi,

Spectrographic

B,

Co

Cr

Bi,Pb,

Cu, Ag

' • *

, Ge, Hi

Cd,Fe,In,Mn, . .Sb,Sn,Ti,V,Zn

Analysis of Phosphorus

0

and

.5-50

1-50

2-50

5-50

i t s

Ppn

n

11

Compounds9«

(M.J. Kamat. T.R. Saranathan and T.S. Sugandhi)

Semiquantitative spectrographio methods have been developed for

the determination of impurities in red phosphorus, PCI, and POC1_* A d.o5 3

aro at .10 amps and large quartz speotrograph are employed for the analysis

of the samples*

Red phosphorus i s mixed with graphite in the ratio 1 it and

analysed for twelve impurities* The detection limits vary between 5 and

100 ppm for the different elements.

Known volumes of PC1_ and P0C1 ere evaporated in a nitrogen

atmosphere in a conical flask immersed partially in a bath of boiling

water* The impurities are oonoentrated on graphite powder and analysed

as graphite sample* The detection l imits for seven impurities vary

between 0.01 g/ml and 0*5 g/ml on a 25 ml sample.

Work i s in progress for improving the sensit ivity, to inolude

mare impurities and to make the method quantitative*10. Studies on Preconcentratlon of Trace Impurities from As-Metal.

As 0- and AsCl prior to Speotrographio Analysis

(7.B. Kartha. P-S« liurty, S.M. Marathe, S.K. Kapoor and M. Saraswathy)

With a view to inorease the sensitivity of various impurities in

As, As O and AsCl , preooncentration of the impurity elements from As

-14-

and i t s compounds by the removal of matrix in the form of volat i le AsCl,

waa studied* In the oase of As and As-O_, these were f irs t converted to

AsCl, by the addition of 5 and 10 ml respectively of OR grade HC1 for

1 gram of the substance and the resulting AsCl, (2 ml of Br2 also was

added for metal sample) was evaporated under an infrared lamp (temperature

about 90*0) under a stream of nitrogen* In the oase of AsCl,, 10 ml of

the sample was used for evaporation. The impurities were collected on

pure graphite powder and analysed spectxographioally* Sjjmthetio standards

for the impurity elements were prepared on graphite base for comparison*

Beeults

(a) Analysis of one As metal sample was performed both directly

and by preooncentration* The values are as given belowt

Values in ppm

Co So I6i Mg Pb Cr Hi Bi* Al Gd Cu Fe Za Ti

Direct 9 900 13 235 70 40 20 7 60 20 23 1100 50 5.5

Preoono. 0.6 320 0*5 11 10 5 1 10 8 1 7 22 5 0.5

It is aesu from the above table that there is a loss for all

impurities during preooncentration* Therefore, the method of preconcentra-

tion is not suitable for arsenic metal. Further studies to improve

recovery are being made*

(b) Analysis of As,0* sample gave the following data*

Co Sb Mh «g Pb Cr Hi Bi* Al Cd Cu» Fe Zn Ti

Direct 5 4500 5 20 45 5 5 7*5 30 25 5 115 50 10

Precocc. 1 1400 1*5 10 45 0*5 1 10 20 25 12 100 25 1.5

The above results show that during preconoentration only Sp is

CONCENTRATION OF Se(p. p.m.)

500

250

100

50

20

10

SAMPLE

2039-85 Se I 2057-68BiI

FIG.2. SPECTRUM OF SELEMIUM IN BISMUTH OXIDE - GRAPHITE MATRIX,

- 1 5 -

lost and the other impurities are retained. Therefore, the preconcentra-

tion technique can be employed for the estimation of elements other than

Sb.

The higher values after preconcentration might be due to residuals

for these elements from acid blank.

11 • Use of Vacuum Ultraviolet Region for Spectrofiraphio Analysis -

Determination of Selenium in Hif.;h Purity Bismuth Oxide

(S.Y, Grampurohit and P. Rugmini Bai)

The earlier method developed in our laboratory for analysis

of high purity bismuth cannot be used for estimation of selenium in

bismuth. A spectrotxaphic method has therefore been developed for the

determination of Se and Te in high purity bismuth oxide. The bismuth

oxide is diluted with epec-pure graphite (111) and excited at 15 amps.

d.c. Since the sensitive lines of Se and Te are in the vacuum ultraviolet

region* the sample is excited in a specially constructed chamber, which

could be attached to the Hilger 3-meter vacuum ultraviolet spectrograph.

20 nig charge i s loaded in the cavity of a \" electrode, which ia mounted

in the chamber with another counter electrode for striking the arc. The

chamber is evacuated and filled with argon and spectra excited at 15 amps.

The spectrum is photographed for 15 seconds on Q« plates in the regiono o

1500 A - 2500 A. Fig. 2 shows the spectra for a set of standards under

these conditions. It has been possible to determine Se to a lower limit

yf 10 ppm. The method appears promising for other impuritiea like As and

I'b as well, thus illustrating the usefulness of the vacuum ultraviolet

region for routine analyses.

(1) T.R. Saranathan and K. Harihara Ayyar, BARC-406, 1970

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12. Spectrographio Ite termination of Im.ingi.tle3 in Hitch Purity Aluminium

(L.C. Chandola and I . J , l.Iachado)

Aluminium i s used an oleddinc und oalandria materials in rcactorn.

'Pile metal so used should be of high puri-fcy and a spectrographic metliod in,

thereforo, being developed to estimate 15 common impurities in aluminium

oxide.

I n i t i a l experiaenta were directed towards establishing a method

using carr ier d i s t i l l a t ion technique. Various carr ies l i ke HaF, AgCl and

0a_0 were t r i ed . AgCl, a t 5?J concentration leve l , gave the best

sensi t iv i ty . For internal standard I*?0** T2 ° * a n d ^M1IA^2 I r G 1 6 W e r e

tr ied. I t was found that Lau0^ a * ^ level gave l ines which were suitable

to be used as internal standard. The carrier d i s t i l l a t ion technique so

developed could noJfi be used as the aluminium oxide samples prepared from

the metal and standards prepared directly on oxide did not behave

similarly. A now method had to be therefore developed for t h i s purpoao,,

In thia method the sample i s mixed with mi equ.il nmount of cr"Phitf», and

20 mg of sample-graphite mixture i s loaded in the preformed onvity of a

i" graphite electrode (UCC 7050). Spectru are exoited in a d.c arc run

at 10 amperes, and photographed on a Hilger large quartz spectroeraph

using SA-1 and II—30 emulsions in the two v/nvelen^th ranees to covero •

2200 A - 35OO A. Investigations hnve aho\m tha* '.vealc l inea of aluminium

serve as bet ter internal standard than oxtern-iUy added lanthanum.

-17 -

Following are the ana lys i s l i n e s and lower l i m i t s of

determinations»

Al 2669.2 i n t e r n a l standard l i n e

As 5280.7 - 10 ppm j B 2497.7 - 10 ppm

Cd 2288.0 - 10 " I Co 2424.9 - 10 "

Cr 2835.6 - 10 " ; Cu 3274.0 - 10 "

Fe 2598.4 - 10 " ; Ga 2944.2 - 10 w

Mg 2779.8 - 10 " j Mn 2605.7- 10 "

Ni 3050.8 - 10 " 1 Si 2435.2 - 100 "

Ti 3199.9 - 10 " j V 3183.4 - 10 "

Zn 3282.3 - 100 "

13. Estimation of Boron in HF

(N.D. Patel, G.S. Ghodcaonkar and V.B. Kartha)

A spectrographic method has been standardised to analyse boron

in hydrofluoric acid. For thia, the recovery of boron from HP has been

tested for a set of standards - 0.05/i fcm/ml to 2.0 M gm/ml. This was

done by evaporating 20 ml HF on graphite in presence of 0,5 ml of 5?°

mannitol. The spectra are obtained by exciting 20 mg of the graphite at

10 amps d.c. NaF and La have been used as carrier and internal standard

respectively. The limit of detection in this method depends on the amount

of HF taken and hence very high sensitivities can be achieved for HF U3ed

in production of nuclear grade uranium. Several samples have been analysed

for the Uranium Metal Plant by this method for detecting the source of

boron contamination in the plant.

-18-

14» Development of a Speotrographio Method for Analysis of High PurityifaOg

(V.A. Job, 0. Krishnanurty, S.B. Kartha. and S. Gopal)

A d»o. arc method i s being developed for the estimation of 23

impurity elements at ppo level in lfaOp. Various exoitation conditions and

buffers were tried. Preignited JtoO2 sample mixed with 5# BaPg as buffer

yielded the best results for high volati le inpurity elements* Conversion

of MnO- to a mixture of more refractory lover oxides i s found to improve

the detection l imits for these elements. For low volati le impurities l ike

Ti» V and Cr, best results are achieved with a 1(1 mixture of MnO and

graphite* The presence of graphite, even in small amounts adversely affected

the detection l imits tor the high volati le impurities* Further work i s in

progress to derive the final conditions for the analysis.

15* Spectrographio Analysis of nigh Purity Nickel Oxide

(N.P. Karanjikar and M.D. Saksena)

A spectrographio method for simultaneous determination of 21

trace impurities in high purity nickel oxide has been developed.

Nickel oxide sample i s thoroughly mixed with the buffer (a

mixture of indium oxide and graphite} in the ratio 1i1. 40 mgs of this

mixture i s excited in a d.c arc at 10 amp in the anode of $" U.C.C.

electrode and using 1/8H U.C.C electrode as counter. The resulting spectra

are recorded on 3,4 metre grating speotrograph with the grating having

1200 grooves/ran and the blaze angle corresponding to 3300 A.

Previous d.o ere methods have analysed nickel only for B to 10

impurities while the present method analyses twentyone trace impurities

simultaneously.

-19-

AIBO the limits reported by the previous methods range between

10 to 100 ppm while the present method reports limits for various elements

in the range 1 to 10 ppm.

The concentration ranges of the various impurities are given

belowi

Ag, Co,Cu,Mn .. 1 - 2 0 ppm

Al,Mg,Na .. 2 - 2 0 "

BifCdfFetPb,Sb,Si,Sn,Ti . . 5 - 100 "

A9,Ba,Cr,Mo,V,Zn . . 10 - 100 "

16. Spectrographio Analysis of Plants for Trace Elements

(M.N. Dixit, G.L. Bhale and H.A. Yaze)

A method has been developed to analyse spectrographioally any-

kind of plant materials for fourteen trace elements. The elements

analysed in the range of 5-500 ppm are B, Cr, Ifa, Fe, Ce, Ni, Cu, Ho, Ag,

Snf Fb and Bi. Zn could be analysed in the range of 100-500 ppm. The

range i s given on the plant ash basis.

The dried plant material i s ashed at 600*G in a muffle furnace

for four hours* The ash i s mixed with an internal standard mixture

containing Ge and graphite in the ratio 1i1i4. 10 mgms of the sample

i s arced in a £" necked graphite electrode at 10 amps d.o. and the

spsctra are photographed on a Hilger large quarts speetrograph in thea

region 2450-3500 A, employing Ilford R-40 emulsion.

The nathod has been successfully used to analyse a variety of

plants l ike casurina, sugaroane, cholam, mangoes, tapioca eto, from the

Saline Water Research Institute, Pondioherry.

-20-

17« Speotroeraphio Analysio of Electrolytic Popper for Trace Impurities

(M.N. Dixit and A.S. Rao)

In view of the non-availability of the copper standards employed

in "globule axo method" whioh i s usually employed in the laboratory for

the analysis of high purity copper, an alternate method has been

developed in our laboratory. By this method the following elements

can be analysed.

Sta, Be . . 1-100 ppm

Ma, Bi, 7 .« 2-100 ppm

Cr, Go, Pb, Sb, Mb . . 3-200 ppm

Ni, Fe, As, Te, Mg, Al . . 20-500 ppm

Samples are analysed in the form of oxide. The samples are

mixed with a buffer mixture and arced at 10 amps d.o. The spectra are«

photographed on E.I quartz speotrograph in the region 2450-3500 A.

The average standard deviation of the method i s about

18» Speotrographlo Determination of Noble Metals in Graphite

(L.C. Chandola and V. Mahajan)

Determination of noble metals even when present in trace amounts

i s important because of their high oost. A method to determine Au, Ga,

Hf, In, Ir , Pd, Pt, Re, Rh and Ru in graphite i s being developed. The

method oonsists of-loading the sample in a shallow cup (UCP 1991)

electrode and exciting the spectra with a d.o. arc run at 10 amp current.

The spectra are photogrnphed in the wavelength region 2500-3500 A on a

large quarts speotrograph. So and Ti l ines are used as internal

standards. Following are the analysis l ines end tentative lower l imits

CONCENTRATION OFOXYGEN tp.p.m.) 7383 98AAI 7724-21A A*! |-777V92AOI

200

100

30

10

844638 A 01

FIG.3. SPECTRA OF TRACE OXYGEN IN ARGON.

- 2 1 -

of determination for different elements.

Au 2676.0 (10 ppra), Ga 2874.2 (10 ppm), Hf 2622.7 (100 ppm),I* 2544.0 (50 ppm), In 3039.4 (10 ppm>, Pd 2673.1 (10 ppn),Pt 2628.0 (50 ppn), Re 3399.3 (500 ppm), Hh 3323.1 (100 ppm)and Bu 2875.0 (50 ppm)

further work to establish the standard working curves and

determinations of precision la in progress.

19« A Speotrographio Method for the Estimation of Oxygen and NitrogenIn Argon

(A. Sethumadhavan, K. Raghuveer end 8» Lakshminarayana)

Investigations have been undertaken to develop a speotrographio

method to estimate oxygen and nitrogen in argon* The spectrum i s excited

by uiicrov/ave discharge in a sealed tube containing argon at a few mm

pressure, and i s photographed on a large glass prism spectrograph. The

oxygen triplet at 7771.9 A i s chosen as analytical l ine and the argon

line at 7723*76 A as the internal standard l ine , as ohoyn in Mg. 3.

The standard gas mixtures have been prepared by mixing known quantities

of 02 and A* Preliminary studies have shown that oxygen could easily be

detected at 10 ppm as i s shown by Fig. 3 . The reproducibility i s however

found to be unsatisfactroy. The work i s in progress to improve the

sensit ivity as well as the reproducibility of the method.

Initial studies on the estimation of Ng in argon showed that

the sensitivity of the emission method using the 0-0 band at 3371.3 A

Of the 2nd positive system of Ng i s not good. Alternate methods to

improve the sensit ivity axe being investigated.

-22-

20. Spectrographic Analysis of Calcinated Bone Ash

(A. bethumadhavan, K. Ra#huveer and G* Lnkshminarayana)

A method i s being developed for spectrochemical analysie of

calcinated bone ash. Bone ash i s made up of Q^j'o calcium phosphate and

15^ calcium carbonate. The matrix of the samples i s simulated by mixing

appropriate amounts of pure calcium phosphate and calcium carbonate and

ignit ing in a furnace for Beveral hours a t about 600°C» The standards

ere prepared by dry-mixing the oxides of various elements with the

simulated matrix. A mixture of LiF (98^) and G& 0 (2}1>) i s used as the

carr ier- internal standard mixture, y/o of th i s mixture i s added to a l l

standards and samples. Gallium l ine at 2418.7 A i s chosen as internal

standard l ine . The spectrum i s excited in a d.c arc a t 10 amps and i se

recorded on the large quartz apectrograph in the region 2200-2800 A ando

2400-3450 A. The elements being estimated are Od, As, % , Fe, Mh9 Pb, Cr,

Hi, V and Zn and the mnge of estimation i s 1-100 ppm.

21. Spectro/yraphic Estimation of Barium in Potassium Bromate

(L.C. Chandola, R, Yenkatasubr aman ian and V,5. Dixit)

The method estimates Ba in KBrO in the range 10 ppm to 10,000 ppni

Element V/avelength Cone.range

Ba 3071.59 10-10,000 ppm ;

Sr ( In t . Std) 2931.83 - {

Preparation of sample 1 The sample i s mixed with en equal amount of )

graphite containing 5$ Sr F .

Preparation of standard si Standards are prepared by dry mixing BaCO with

KBrO,. 3fti<* standards prepared contained 10,100, 500, 1000, 5000 and

-23-

10000 ppm Ba on KBrO .

Speotrographio procedure i

Spectrograph

Region

Emulsion

Charge

Aperture

Source

External optics

Exposure

Large quartz spectrograph

10 urn

2800 A at the lower end

Ilfard E 40

10 rng on UCP 1991 eleatrodsjcounter 1/8" pointed

3 mm at collimating lens

D.C arc at 10 amps.

10$ filter

1 minute

22. Speotrographio Determination of Europium in Lithium Fluoride

(L.C. Chandola, R» Venkatasubramanian and V.S. Dixit)

The method estimates Bi in LiF in the range 10 ppm to 10000 ppm.

Element

Eu

Wavelength

2815.95 A

Concran/te

10 ppm to 1

ofBa ( I n t . Std) 2702.64 A

Pr eparation/sample i The sample ia mixed with an equal amount of graphite

containing 10j£ barium fluoride to provide internal standard.

Preparation of standardsi Standards are prepared by dry mixing B*2°3 ^ ^

LiF and eaoh standard i s mixed with graphite containing 10$ BaF2 in the

ra t io 1*1. The standards prepared contained 10,100, 1000, 5000 ppm a» on

LiF.

Spectroflraphio Proceduret

Spectrograph . . Large quarts

S l i t width . . 12

- 2 4 -o

region . * 2600 A at the lower end

Emulsion . , R-40

Charge . . 10 mg on UCP 1991 alectrodei

counter 1/8" pointed

Aperture «• } mm at colliroabing lexis

Source «• D.C aro at 10 ampB

External optics . . 10$ filter

Exposure . . 1 minute

2% Speotropraphic Method for the Analysis of Simulated Air. Filters

(G. Krishnamurty, M. Saraswathy and 0. Thoraaa)

The aim of this project is to quantitatively estimate the elements

Fb, Hg, Mn, Cr, As, Cd, Vf Fe, Ni and Zn in air by drawing air samples

through f i l ter papers in various environments. Studies are in progress to

develop a spectrographic method for the estimation of "these elements,

collected on the filter*

In order to find out the presence of various elements in the

environmental samples, a large volume of sample was used and samples in

various environments were collected on Whatman 41 f i l te r paper. These

fi l ter paper samples were ashed and the residue was collected on graphite.

Quantitative analysis of these samples showed the presence of the elements

Si, 1%, Ca, Ti, Cu and Al in higher concentrations (per cent) and !flh, Fb,

Cd, Cr, Ni and V in trace amounts (ppm range). Elements Hg and As are

likely to be lost in the process of ashing the fi l ter paper. So, in the

present studies investigations are being carried out to extraot all the

impurities present in the sample on the f i l ter paper by leaohing. In

-25-

addicion to the f i l t e r paper Whatman 41, another variety of filter -

Millipore - i s also being tried to co l lec t the samples.

24- Analysis of Freeh Water Samples for Qommon Pollutants

(J« Banaourti and N.P. Karanjlkar)

A method i s being developed for analysis of fresh water samples

for pollutants l ike Pb, Hg, Zn etc. She sample i s evaporated on graphite

and analysed apeotrographioally. Tfap water, d i s t i l l ed water, deionised

water and triply d i s t i l l ed water ware tested aamiquantitatively to get an

idee of impurities l ike Pb, fclh, Cr, As, Cd, V, Fe, Ni, Zn etc. present in

fresh water as well as the possible blank values* The triply dist i l led

wn+.er woa found to be sufficiently free from blank. The impurities were

found to be only in parts per bi l l ion range* The graphite standards c

containing the above-mentioned impurities are prepared. Using these

utundards, a study for the recovery of the elements in water i s in progress.

The preliminary study has shown that recovery loss in case of Hg i s very

high. Further work i s in progress.

25. Spootrographio Methods for Analysis of Soil Samples

(V.P. Bellary. Y.A* Sanaa and VOB. Kartha)

In order to detect background level of various elements in so i l

app le s a spectrographio method i s being developed for the analysis of

these samples. A matrix simulating soil i s prepared by mixing 'spec-pure1

SiO (63#), Al o_ (2O?5). Pe-0, (5#). NaoC(L (3.595), CaO ( 2 $ , MgO (5$) and

TiC2 ( i^)i and igniting the sample overnight at above 800-C. To the

simulated matrix known amounts of impurities are added so that oonditions

foi speotrochemical analysis could be fixed. I t i s proposed te study both

-26-

direct and preconcentrati.cn methods for the determination of trace

amounts of As, Cd, Cr, Fe, Ilg, Ni, Mn, Pb, V and Zn.

26. Spectrographio Determination of Impurities in BaCl?

(0 .3 . Ghodgaonkar and V.B. Kartha)

A spectrographio method for the analycia of purs BaCI , for

trace amounts of Al, Cu, Fe, Pb and Si has been developed* The BaCI,,

sample i s mixed with an equal quantity of spec-pure graphite* 20 mg of

the above mixture i s excited a t 10 amp d.o, for a period of 45 seconds*

The spectra are photographed on Hilger large quartz spectrograph in thee

region 2450-5500 A, The impurities are analysed in the range 5-500 ppm.

Further experiments are being done to improve the sens i t iv i ty and

precision of the method.

27. A Bemiquantitative Method for the Estimation of Thrace Impurities inSulphur

(R,0. Naik, K. Harihara Ayyar and P.D. Karnifc)

A semiquantitative d.c arc method for the analysis of high

purity sulphur for trace impurities has been developed. Sulphur and

graphite are mixed in the r a t i o 2»1 and 50 mg of charge i s loaded in the

cavity of a i" electrode and arced in a low current d.o arc running at

6 amp* The spectra are photographed in the second order of a 15000 l i n e s /

inch grat ing using SA-I p l a t e s . Tho wavelength region covered i se

2200-3250 A. The impurities estimated are As, Te, Fe, Al, 1%, Mh, Cu, Cr,

Ni, Pb, Ag, Sn, In, Ga, Zn end Ca. The lower l imits of estimation varies

from 5 ppm to 50 ppm depending on the nature of impurity.

-27-

2fi« Simultaneous Analysis of Ag« Mo and Ca in Uranium

(R.M. Dixit, P.P. Khanna and S.S. Deshpande)

A d.c aro oarrier dist i l lation method for the simultaneous

analysis of Ag, Mo and Ca in uranium has been worked out. There were

two different carrier dist i l lat ion methods for analysis of these three

elements in our laboratory. The present method by combining the two

methods outs down the time and cost of analysis, A new carrier, a

mixture of 5$ Sb 0 and 5$ Bad has been used in this method. There

i s a general improvement of sensitivity in Mo estimation* Ag and Mo are

estimated in the range of 1-20 ppm and Ca in the range of 10-200 ppm.

The average percentage deviation of the intensity ratios works out to be

+

29. Measurement of Temperature« Electron Pressure and Degree ofIoniaation in Plasmas Generated by D.C Arcs

(R.C. Naik and P.D. Karnik)

A conventional d.c arc running between the two graphite electrodes

is supposed to be a body of partially ionised gas plasma and i s the seat

oi.' all theriaochemical processes and excitations in the arc. There are a

number of parameters such as the temperature, electron pressure etc*

which directly or indirectly control many of the processes in the aro.

The present investigation was undertaken to study some of these parameters

under various conditions of excitation and when different extraneous

elements are present, tn the aro plasma. The parameters chosen for investi-

gation are the effeotive arc temperature, effective electron concentration,

the degree of ionisation, sum of 'sathode and anode fall potential (V& + ?Q)

and the voltage gradient along the arc axis.

-28-

The effeotive axe temperature, electron pressure and degree of

ionisation were determined for a d.o aro running at 10 amp* and when

different substances like AgCl, GagO , NaP, LiF, A l ^ , 3rCl2 formed the

major matrix. Each of the above compounds was mixed with graphite (in

the ratio 111) containing 10 ppm of Mg to be used as a manometric element

and 0«1$ of zinc to be used as a thermometric element. Fifty oilligramB

of charge was taken in the cavity of a £" UCC electrode and the spectra

were recorded on a medium quartz spectrograph, using an aperture to out

off the electrode tips. The so called two line method with Zn 5076 A

e

and 3072 A l ines was used to measure the temperature* The electron

pressures were measured by using the intensities of the atomic and ionic

lines of magnesium eg. ISg I 2052 A and Mg II 2796 A. The degree of

ionisation was calculated for different species from the temperature and

electron pressure values obtained above.

Voltage gradient along the aro axis ( T") and the sum of

cathode and anode fall potential (V + V ) were also measured for AgCl,

La20 » LiF, Ga29 . A10 . . Nal etc. under different excitation conditions.

The variation of these parameters, when metal vapour concentration was

varied and also when sample electrode i s made negative* were studied.

30. MISER - Micro Spectral Emission AnalyseR

(S.L.N.G. Krishnamachari and B.R. Vengsarkar)

Analysis of microsurfaces (surface areas around 100 Bquaxe

microns) i s find.Tg increasing applications in nuclear technology.

metallurgy, micro electronics, archaeology, medicine and biology^ To

quote a few il lustrative examples, i t has been used to determine the

-29-

distribution of aluminium and silicon in intermediate areas of the

•lumlum/uranium boundary layers of canned uranium cores, to determine the

phase constituents in iron and/or silicon alloys of uranium, to study the

distribution of nickel in explosively bonded copper-niokel alloys, to

identify inclusions, to determine the major metallic constituents in

different layers in microcircuitry, to study the distribution and concen-

tration of trace elements in human and animal tissues and in plants and

in the investigations of the dust diseases of the lung. In view of i ts

importance, a projeot for the fabrication of a Micro Spectral Qiission

analyseR (MISER) has been taken up. This consists of. two phases. The

first phase consists of building the instrument utilising a microspark

source for the extraction and excitation of the elements and the second

phase consists of incorporating a laser source for the extraction of the

elements and a spark source for the excitation of the spectra. All the

components required for the first phase like the microspark excitation unit,

metallurgical microscope and a high speed speotrograph are being fabricated

and procured. She miorospark unit was fabricated in the division and

consists of a high voltage (1750 V) unidirectional spark source incorporating

oondensers (0.001 jiF to 0.1/jF) parallel to the spark gap, and inductance

(100 to 400 mE) and resistance (25 to 200-A) in series with the spark gap.

With the help of this < excitation unit, the emission characteristics of the

spark were sir died. The spark spectra of microsurfaces of steel samples

were studied with different counter electrodes like tungsten, silver, copper

and graphite, and i t was found that the w^™™ intensity of the iron lines

could be obtained with tungsten as the counter electrode. The effect of

polarity of the electrodes on toe intensity of the emitted speotra was also

studied. The diameter of the crater obtained after sparking was studied

- 3 0 -

as a function of the L, C & R of the circuit , the exposure time and the

spark gap.

The microscope that was used to scan the surface was a

metallurgical microscope purchased from an indigenous firm and was

fitted with a turrent type objective carrying three objectives of

different magnifications. One of these objectives was replaced by an

eleotrode holder to whioh a 1/8" diameter pointed tungsten counter

electrode (cathode) waa fixed. The sample was fixed to the microscope

stage whioh was made the anode, A. short focal length (f « 1M) lens

formed a magnified image of the source on the s l i t of a Hilger small

quartz spectrograph. Spectra were recorded photographically (using

Kodak 103 a-o and B-10 emulsions) with exposure times of the order of

10 seconds.

31. Spectrographio Analysis of Boron Nitride for Trace Impurities

(B.H. Vengsarkar, I .J . Machado and S.K. Malhotra)

The emission spoctrographic method previously developed for

analysis of Boron nitride has "been improved and modified. Present

me'thod can be used for analysis of Al, As, Bi, Ca, Fe, Ife, Pb, Sb and

Sn in boron nitride, The method consists in exciting in a d.c. arc at

10 amps,, a charge of 30 mg containing boron nitride and graphite in

equal quantities. The mixture contains zfo NaP as a carrier and V/»

lanthanum oxide as an internal standard. The spectra are recorded on

Hilger's large quartz spectrograph in the region 24OOA - 335OA. The

method i s useful in the determination of impurities in the range of

2 to 1000 ppm for different impurities with a mean percentage standard

deviation of +

- 3 1 -

I (b> X-RAY i'LUOllBSCEKCE SPE0TROS0OPY

1. Effeot of Field Theoretioal CorrectionB on X-ray Spectra - EnergyLevels of Some L Lines of Heavy Elements

(T.V. Krishnan)

A correct knowledge of the energy l e v e l s , o s c i l l a t o r strengths,

absorption c o e f f i c i e n t s , fluorescent y i e l d e t c w i l l help in accurate

determination of impurities in ana lys i s , especial ly in s ingle sample

methods. Also the calculat ion and checking of the fundamental parameters

in spectroscopy i s constantly necessary to verify and rev i se the

theoret ica l basis of the calculat ionsi Attempts are therefore being made

to compute these parameters for x-ray epectra. We have observed that

the one electron model i s very useful for th i s purpose and that a

modification of the usual Sommerfeldfs formula i s necessary to calculate

the energy l e v e l s of the inner s h e l l s of heavy elements. The accurate

r e l a t i v i s t i o energy i s given by the modified Sommerfeld - Dirao energy

formula given belowi

M)-~l SLlI^d.^1 «2(7 )

[n'+ (K2- «2(z-<r2frjwhere **1 and °"2 are Sommerfeld1 s screening constants, and

k - J + it n' • n-k.

The one electron model was further extended by tho addition

of Lamb shift and other field theoretical corrections to oaloulate the(2)

wavelengths of E lines, energy levels, intensity ratios etc. «

-32-

At present the wavelengths of L f$,t L p . , L f^, L tf , s and t

l ines have been caloulated for elements of atomio number 70 to 92.

Further work i s in progress.

1. T.V. Krishnan, Ph.D. Thesis, University of Bombay, 1971

2* Effect of Field Theoretical Corrections on X-ray Speotra by T«V,Krishnan and Amar Nath Nigam, Proc. Ind. Aoad, Soi, LXX7II,A, 26 (1973)

2. Trace Rare Earths in Nuclear Materials by X-ray Excited Optioal.Fluorescenoe

(T.R. Saranathan, M.J. Kaaat and T0S. Sugandhi)

Chemical separation procedures axe usually used for preconoen-

tration of trace amounts of rare earths in thorium and uranium before

spectrographio estimation. A direct method of analysis involving much

shorter time i s provided by X-ray excited optioal fluorescenoe techniques

Thorium and i t s compounds are converted into oxide and analysed

for C-d, Sm, Dy, Eu and Pr with detection l imits 0.04, 0 ,1 , 0 . 1 , 0.04 and

0*1 ppm respectively.

Uranium and i t s compounds are in i t i a l l y converted into U.Qa

whiah i s mixed with suitable quantities of W_, SrCO and LigCO and

fixed in a muffle furnaoe at 74O*C. The resulting compound formed after

3 hours i s analysed for the rare earths.

Samples whioh form the pure and produots l ike UO-t UO and

U-metal in the Ura>iua Plant and the pure samples of Th oan be analysed

without difficulty. As the method Is sensitive to the presenoe of other

Impurities, the limitations of the method with respeot to samples reo«iv«d

-34-

prepared by using standard solutions of the elements to be determined.

X-ray intensit ies of characteristic analytical lines from the standards

and samples are measured and are used to determine the composition of

the al loy.

5» An X-ray Fluorescence Method for Direot Determination of Uraniumin Thorium

(R.M. Dixit and S.K. Kapoor)

An X-ray fluorescence method has been developed for the

analysis of uranium in thorium. The oxide sample i s made into a pellet

with 5G/o boric aoid as binder. Tungsten target tube at a power level of

70 KV - 50 mA and LiF analysing crystal have been found to be most suitable.

U-KoKline i s used as analytical l ine . At present the lower limit of

estimation i s 50 ppm of U_0o in ThO . Further studies to analyse other

impurities l ike Zn, Zr etc. in ThO, are in progress.

6. Estimation of Hare Earth Impurities in Hare Earths

(It.Me Dixit and S.S, Deshpande)

A number sf X-ray fluorescence methods have been developed for

the analysis of pure rare earth oxides, for other rare earth impurities.

At present methods are available for s ix different rare earths. These

are given below 1 s

ft) Yttrium Oxide

The sample i s converted to oxalate and analysed in the form

of a double layer pel let using 50$ boric acid as binder, tfhe estimation

range i s 0.005$ to 1.($ for most of the elements. A tungsten target

X-ray tube at a power level of 60 K7 at 35 na has been used to «xoite

-33-

in our laboratory are being studied.

3. X-ray EIuoreBcence Analysis of Low Alloy Steels for Mo. Ni, Mh andCr and Plain Carbon Steels for Mn

(H.M. Agrawal and P.P. Khanna)

Samples of suoh stee ls for XRF analysis are generally converted

into discs of dia 1^" or 1^JI with one circular face made plane with good

surface f inish. Samples of smaller sizes can also be bandied using

standard masks. Rapid quantitative XRF analysis i s possible for the

elements mentioned above in their usual concentration range, using the

standards obtained from*Bureau of Analysed Standards1. The standard

deviation of the method i s about

4» Chemioo-XRF Analysis of Stainless and High Alloy Steels

(H.M. Agrawal, P.P. Khanna and S.K. Malhotra)

XRF method for the analysis of stainless end high al loy steels

require elaborate computations to account for the matrix effects which

are quite large. Moreover, the sample i s required to be converted to a

diso of standard size whioh may not be always possible. Non-availability

of the complete set of standards similarly poses a problem in the direct

XRF analysis of the samples. Therefore, a, ohemico-XRF method for the

analysis of S,S. and high alloy steels has been developed particularly

for samples which are available in the form of turnings or in small

quantities only. The method, in addition, has the advantage that effects

due to inhomogeneiiy in the sample are eliminated. Though the method

takes longer time as oompared to direct XRF aethod, i t i s muoh quicker

compared to the chemical methods of analysis.

Suitable standards in the f«en of double layer pe l l e t s are

- 3 5 -

X~ray emission. LiP crystal has been found to be most suitable as

analysing crystal. Line interferences and the correction for interferences

have been examined. The precision and accuracy of the method ia better

than + $

b) Lanthanuum Oxide

An XRP method aa above has been developed for the analysis of

Ce, Pr, Nd and Sm in La?0_. In this caae, the range of estimation i s

between 0.025$ and 1.0$ for Pr, Nd and Sm. Lot lines of these elements

could not be uBed in this method beffause of interferences. Ce-Lot. line

i s however interference-free. The experimental conditions are the same

as for YgO .

c) Samarium Oxide

An XRF method for the determination of Ce, Pr, Nd, Ba, Gd and

Y in 3m_0 has been worked out. Oxide samples are converted to oxalatee

and analysed as double layer pellets. The lower limits of estimation i s

0.025$ for Pr and Eu because the most intense LoC l ines of these elements

could not be used in this problem. The Gd-L«-j line suffers interference

from Ce-L/ 1 l ine. As there i s no other suitable line for Gd, this LoC

line i s corrected for Ge-LV,. interference.

d) Gadolinium Oxide

An XRF method to estimate Nd, So, Ba, Tb, Iy and T in pure

Gd 0 has "been worked out. The range of estimation is generally 0.005$

to 1.0$. At present the lower estimation range ia limited by the purity

of the available GdgQ^ blank.

-56-

«) BysproBium Oxide

An XRP method to estimate Eu, Od, Tb, Ho, Br and Y in Hysproaiua.

oxide has been worked out. The estimation ranges are 0.005$ to 1.C$ for

many elements. But whereever residual correction i s required the estima-

tion limit i s altered.

All the above five methods have been tested for accuracy which

1B within + 10$.

f) Rare Earth Concentrates

X-ray emission spectrometrio method developed for yttrium oxide

has been adapted to analyse rare earth concentrate sample containing

heavier rare earths in percentage ranges* The concentrate i s dissolved

in nitric acid and i s diluted. Known amount of this diluted solution i s

added to yttrium oxide in solution and precipitated as oxalate. Impurities

in yttrium oxalate are then estimated.

7» Determination of Calcium in Uranium

(R.M. Dixit, S.S. Ceshpande and S.K. Kapoor)

An X-ray emission spectrometrio method for the estimation of

oalcium in uranium in the range of 20-200 ppm has been developed. The

sample i s mixed with 50$ boric acid as a binder and analysed in the form

of double layer pel let . Tungsten target with 55 KV-35 mA power i s used.

IIP analysing crystal has been found to be most suitable.

- 3 7 -

99 Hare Earths In Minerals by X-ray Exoited Optical Fluorescence

(M.J. Kamat, T.R. Saranathan ond T.3. Sugandhi)

Studies on rare earth distribution In minerals like uranimites

are of geoohestical interest. The possibilities of obtaining the rare-

earth fluoresoenoe from the minerals inoorporated in suitable hoBts are

being worked out*

Initial experiments with potash feldspar showed fluorescence

emission when the sample i e diluted with pure TJ_OQ and fired at 800eC

in a muffle furnace after mixing with W0_, SrCO_ and LigCO . The

fluorescence spectrum is shown in Fig. 4*

Work i s in progress with other minerals like uraninlte,

pyroohlore and monazite.

9, XRF Deteraination of the Exact Composition of Arsenic SulphideCrystals

(R.M, Agrawal and 3.K. Malhotra)

Small pink single crystals of arsenio sulphide were grown from

vapour phase by Technical Physics Division for studies of their

slectrioal and other properties. They expected the crystals to 1» of

the composition corresponding to formula AflgS but the experimental

observations cbuld not be correlated to the compound of suoh a. formula.

Therefore the determination of the exact composition was required.

Very small quantity (a few milligrams) of ike sample oould

only be spared fcr the analysis and as such conventional chemioal methods

oould not be applied. Speotrographio methods could not be used as they

are accompanied by large uncertainties (standard deviations). XHT method

-38-

O

ID

UJI

FELDSPAR KAISI3O8 (Natural)

ooCO

CD

FIG. 4. FLUORESCENCE EMISSION OF RARE EARTHSIN POTASH FELDSPAR.

-39-

been developed for investigating the problem.

An exaotly known weight of the sample was taken in an 100 ml

stoppered oonioal flask, covered with carbon tetrachloride and subsequently

oxidised using fuming n i tr ic acid followed by final oxidation using ILO .

The final products after dissolution and chemical treatment exist in

solution as converted to sodium arsenate and sodium sulphate* High purity

sulphur and elemental arsenic were similarly oxidised to get the standard

solutions of sodium at senate and sodium sulphate. 3!he solution obtained

after oxidation of arse- <j Iphide •i-ystals !ME r.e i analysed for arsenic

and sulphur using cellulose absorbent technique of XRF analysis using the

standard solutions of sulphur and arsenic prepared in a similar way.

"Reagent Blank" has been used to correct for the l iksly As and S impurities

in the reagents used. This enabled tha precise and accurate determination

of the composition of the crystals whioh corresponds to the formula

10. XRF AnalysiB of Neobite/ffantalite Concentrates for Tantalum

(BeM. Agrawal)

Since only one element has to be determined and that too in

the percentage range, spiking technique with inert dilution was considered

to be the most appropriate and quick. The sample i s ground to a fine

powder and mixed with known proportion of quartz powder. Pure TagO,. i s

dry mixed with quartz powder and thoroughly ground to a fine mixture.

Suitable amounts of this mixture are used to spike the sample. Finally

the sample and the spiked samples are separately mixed with a binding

material and briquetted to pel lets of standard size* X-ray intensities

-40-

of characteristic Ta-La l ines axe measured for the sample pel let and

the spiked sample pellets using LiF crystal scintil lation counter with

pulBe height discrimination to eliminate the second order interference

due to Nb-K line. From the intensity data the concentration of Ta i s

determined using the standard procedure.

The results axe found to be in very good agreement with those

obtained by chemical methods of analysis*

11. An XRF Method for Analysis of NdgO and P^O

(T.V. Kriohnan and P.D. Karnik)

A method has been developed for the determination of La, Ce.

Pr, Sm, Eu and Gd in Nd 0 in the range .005$ to 1$. The oxide i s

converted into oxalate and pel lets made with 400 mg of oxalate with 50$

boxio acid as binder* Borio acid i s used as a backing pe l l e t . Details

are given belowt

W-target tube at 60 KV 35 mA. Fine collimator. Flow oounter

at 1670 vol ts 250/250 base and window. Analysing crystal - LiF - 1st

order.

Analytioal l ines;

La - Lc<1, Ce - Le^, Pr - Lot ,

Sm - ! P i f BU - LP 1 ? Gd - L p ^

A similar method has been developed fox the determination of La.

Ce. Hd and Sm in praseodymium oxide. The analytical l ines used are

La - Lfl^. Ce - Lc^, Nd - Lot , and Sm - Lp , The experimental conditions

are the same as above.

I t i s obse-.-rved that the values.of 2 9 for the peaks of the

- 4 1 -

above l ines are slightly different for different matrices. As the angles

depend not only on the matrix but also on zero errors in the particular

instrument, i t i s to be determined for each instrument separately. Hence

the values of 2 0 are not given here but only the analytical l ines used

are mentioned*

12. Study of the Changes in the Layer-composition of a Cu-Hi Tube Dueto Corrosion by Sea-v/ater Using X-ray Fluorescence Spectrometry

(R.M. Agrawal and P.P. Khanna)

Copper-nickel alloy tubes are used in IAPP as heat exchangers

and coolant carrier, due to their good thermal conductivity and corrosion

resistance. However, because of constant erosion due to sea-water which

is used as a coolant, these cupro-nickel alloy tubes were found to be

corroded. One such tube sample has been sent to this Division to determine

the changes in the composition of the corroded layers at different depths.

X-ray fluorescence teohnique has been used for this investigation.

A flattened piece of the tube was embedded in paxafiin war

leaving a measured area of corroded surface uncovered for removal and

collection by etching. The corroded Burface has been etohed out by nitric

acidt water mixture, successively in batches, using measured Tolume of the

etchant eaoh time and collecting the resulting solutions separately. Thus

the layers at different depths of the corroded surface have been etched

and collected separately as solution. The solutions so obtair.sd have been

analysed for the amount of copper and nickel present in them using oelluloso

absorbent technique of XRF analysis.

The results conclusively proved that copper has been preferentially

washed away from the layers immediately in contact with the coolant

-42-

sea-water, resulting in the increased Ni/Cu rat io . The nominal composi-

tion of the tube material was 90?S Cu - 10$ Ni. Outer surface which did

not come in contact with sea-water had been found to have the above

composition* However, the inner surface of the tube which remained in

contact with flowing aea-water was found to have become relat ively

porous to a depth of about 3000 A, The average composition of these

relatively porous layers has been found to be 38$ Cu, 62$ Ni (average

for layers between depths 850 A to 3000 A from the inner surface).

Thereafter, there i s a relatively rapid increase in the Cu/Ni ratio

which rises to 5.3 (84$ Cu and 1696 Hi) within the next 1000 A, which

then gradually increases to 9 (the nominal /normal value) in the next

few thousand A. Thus in the tube examined a l l the changes in the

composition were confined to layers within one micron depth from the

inner surface, the depletion of copper being maximum on the top layers

and becoming l e s s for deeper layers.

13. X-ray Fluorescence Analysis of High Purity Ta O and Potassium

Tantalofluoride for Nb« Fe, Mh and Ti

(R.M. Agrawal and P.P. Khanna)

An XRF method has been standardised for the high purity TfcpO-

and K TaF. The method consists in dry mixing of the sample with known

proportion of boric acid (as a binding material) and making a double

layer pellet with boric acid pellet as a base* Standards arc prepared

by dry-mixing of known amount of impurities in pure Ts 0 and X TaF,-

and subsequently preparing double layer pel lets as wife the samples.

Standards containing impurities ranging from 20 ppm to 1j6 have been

prepared The fluorescent intensit ies of the analytical l ines

-43-

of the impurities are measured for standards and unknowns, and are

correlated after applying the background corrections wherever necessary.

The calibration graph i s linear in the range examined. The limits of

determination obtained i s 50 PPm for Fe, Hh and Nb and 20 ppm for Ti.

The standard counting error ranges from + 0.5$ to 8# depending upon the

concentration range*

14* X-ray Pluorescencc Analysis of Calcium Sulphate Doped with Dyand/or Tin

(R.M. Agrawal and P.P. Khanna)

An XRP method for the analysis of Dy and/or To in CaSO. doped

with Dy and/or Tm has been developed. The procedure i s similar to one

described for high purity TSgO and KgTaF . Range of analysis i s .005$

to 2$.

The analysis i s required by Health Physios Division in

connection with the development of Thermoluminisoent Dosimeters.

15. X-ray Iluorescence Analysis of High Purity H A for Race Earths

(R.M. Agrawal and P.P. Khanna)

Using a Bimilar XRF technique as described for T s ^ t individual

rare-earths can be determined diraotly in I-Og (Uranium and i t s other

compounds after conversion to U,0_). The l imit of detection is 10 ppn5 8

for most of the rare earths.

Range of analysis 20 ppa to

-44-

16* X-ray fluorescence Analysis cf U 0 for Chlorine and Bromine3 8

(E.M. Agrawal and P*P* Khenna)

Using teohnique similar to the one used for high purity

Cl1 and Br1 can be determined in U 0 (or in metal and other oonpounds3 8

after conversion to U 0 ) to the lover limits of 50 ppa and 20 ppa3 o

respectively* These impurities oan lie analysed i f present upto 1^.

17» XRF Analysis of Individual Rare-Earths in Rare-Earth Mixtures andHare-Earth Concentrates

(R.M. Agrawal, P.P. Khanna and S.K. Malhotra)

Cellulose absorbent teohnique of X-ray fluorescence analysis

has been successfully used for the analysis of individual rare-earths

in rare-earth mixtures and the results ar« found to be in good agreement

with those obtained by using another method of Inert Dilution* A

systematic comparative experimental study of the various XRF techniques

available for the analysis of such a complex mixture i s in hand, in

order to evaluate their merits and limitations*

-45-

l ( o ) ATOMIC ABSORPTION AMD ATOMIC FLUORESCENCE

(S.V. Grampurohit and M.H. D ix i t )

Invest igat ions on the application of atomic absorption and

atomic fluorescence techniques for analys i s of elements which could be

determined only v l t h d i f f i c u l t y by spectrographio methods, are being

carried out in our laboratory. Also inves t igat ions in s e t t i n g up of

atomic absorption and atomio fluorescence equipments, construction of

hollow cathodes and e leotrodeless discharge lamps and fabrication of

power supplies for holl rtr cathode lamps are being undertaken*

A large number of s ing le element hollow cathodes l i k e iron,

copperi s i l v e r , molybdenum etc* have been fabricated in the l a s t year.

Some iron-hollow cathodes have been supplied to other laboratories .

In addition some multielement hollow cathodes l i k e , Ag-Mo,

Cu-Mg-Ca e t c have been prepared.

The ex i s t ing hollow cathode power supply i s modified and i t

i s used to supply pulsed power at 50 and 100 cyc le s .

Two front - s i lvered concave mirrors are fabricated to be used

for the atomic f luorescence se t up*

-4b-

i (d) IMKRARH) AHD BAMAN SPEOTROSCOPY

1. Infrared Spectra of Boron Trifluoride

(N.So Patel and V.B. Kartha)

A complete understanding of the vibrational spectra of BF i s

of importance in view of the use of this compound at one stage or another

in ieotopio separation of B and B. Infrared spectra of BF, in gas,

solution and solid form are being studied both for development of

methods for isotopic analysis of BF-. as well as for understanding the

molecular dynamics of systems containing BF,« Rreliminary investigations

have shown that by the ratio of intensities isotopio analysis could be

carried out to an accuracy of better than 0.5$ at the natural range.

Further work i s in progress.

2. Non dispersive Infrared Analysis

(V.B. Kartha)

During the design of a non-dispersive infrared analyser for CO

analysis in ppm range, preliminary investigations showed that design of

a sensitive pneumatic detector can be improved by fitting of the various

parameters l ike absorbing gas pressure, absorbing gas - inert gas ratio,

and shape, s ize, path length eto. of the detector cel l . In order to

optimise a l l the parameters for any individual analyser, a computer

programme i s being written.

-4?-

I ( a ) I80T0PIC jftWAT.YCTR

1. Iaotopio Analysis of Lithium on Baoording Fahry-Perot 3oectrog«tgr( R E E P O S ) .

(S.A. Ahmad* O.D, Saksena and A* Tenngopal)

Among the various methods employed for the isotopio analysis of

an element, the high resolution speotroscopy method has proved to fee

quite satisfactory* Under suitable conditions of exoitation, the measured

intensities of the isotopio component are proportional to their abundanoe.

An optical method was developed for isotopio analysis of Li by7 6

oeasuring the intensity ratio of Li and Id components in the LI 6738 Aline by recording the isotopio structure in the Recording Fabry-Perot

(2)spectrometer v (REFPOS). The method differs in some aapeots from othermethods published. Some modifications have been incorporated and now the

7 6isotopio structure consisting of Li and Li components i s recorded by a

modified technique of slow and fast scanning. This has improved the

aocuracy of the results and reduoed the time taken per sample for analysis.

The sample in the form of U-o30! i s e x o i t e d *" a liquid-air-cooled

hollow cathode lamp. The l ine 6708 A i s a resonance line and hence shows

self-abBorption. Using Li (99.4$) i t was found that when 2 jig of Li i s

used and a hollow cathode current of 10 s£ i s employed there i s no self-

absorption and the measured intensity ratio of 1 i2.G2 i s very olose to theJ> 2 2 2

theoretical 182 intensity ratio of the doublet **j2 " 8 i h * P i / 2 " 8 i /2*

Using a multiple hollow cathode assembly, standards and samples

are ezoited simultaneously and recorded one after the other. The exit and

entrsao* s l i tB of the monoohromatar are kept at lOOOpm and 350»»r«speotively,

The Fabry-Perot plates used are of 7.0 oa dia and have i ie lectrio ooating

-48-

for best performance at 6800 A. The spacer used is 4.29 no.6

Using this method, the oonoentration of Li in natural Li

samples were found to be 7*4 ± 0 . 5 * A few synthetic samples were Bade

with Li (99.92$) and Li (99.396) and the samples expected to show Li

as 4.8$ and 13.2$ were analysed to have 5*0 + 0.2$ and 15.1 + 0.3#

respectively.

A few of the samples which were already analysed on HEPPOS

were checked with mass spectrometer rfsults. A comparison of the

results obtained by the two methods i s shown below I

Samples

CCEB-Hf

CCEB-2/6

" 3 N K

4/CCEE-E

4/CCEB-Ew^

Results reported on

28-2-72it

10-3-72

24-4-72N

Our values

7.6 + 0.5

5.6 + 0.5

5.5 ± 0.55-6 + 0.5

6.0 + 0.5

Mass spectrometervalues obtained iaSeptember 1972

7.8 + 0.05

5.7 ± 0.055.3 ± 0.055.8 + 0.05

5.9 + 0.05

About 80 samples received from Chemical Bagineering Division

and Chemistry Division were analysed during the yearo

1) Lithium Isotopio Analysis on Recording Fabry-Perot Spectrometer,BARC/5O8/197O - S.A. Ahmad and O.D. Ssksena

2) "Setting up of a Recording Eabry-Perot Spectrometer11, BARO/290/1967G.D. Saksena and S.A. Ahmad

-49-

I (f) ANALYSIS OF GASES IN METALS

1. Determination of Qaeea in Matala by D»C« Aro GasohronatographloTechnique

(A.P. D'Silva*, P.K. Wahi and S,S. Biswas)

Oxygen, nitrogen and hydrogen ere common gaseous impurities

generally present in trace amounts in metals. They exist either in

chemical combination or as solid solutions. These impurities profoundlyi

affect the physical,1 mechanical and electrical properites of the metals.

Thus, their rapid and acourate determination has become necessary.

The technique originated by Fasael et el has been adopted(2)

after modifications for the determination of nitrogen and oxygen ,

and hydrogen in tiro separate determinations. Recently, we have in

our laboratory extended the method ' to the simultaneous determination

of IL» H and 0 using indegenously available argon and tritium £ -ray

ionisation detector of Shahin and Lipsky design. The method has been

found to work satisfactorily and a variety of samplea such as steel,

copper, zirconium, titanium and molybednem have been analysed. The

method has several advantages over conventional vacuum fusion technique.

The Schematic diagram of the apparatus "fabricated i s shown

in Fig. 5. The order of elution of gaseous impurities i s shown in Fig. 6.

A known amount of the sample or sample + bath materials (platinum for

refraotory metal samples) i s supported on a degassed graphite eleotrode,

and the sample melted by a D.O. aro in chamber (2), filled with argon

at 700 torr», when nitrogen and hydrogen are evolved in the moleoular

fora, while oxygen oetbinea with the graphite of the eleotrode to form

ARGONINLET

1. a) MOLECULAR SIEVE, b) SILICA GEL. c) FLOW METER.

2. CHAMBER 9. B - RAY IONISATION DETECTOR

3. FORE PUMP 10. AMPLIFER4. DFFUSION PUMP 11. RECORDER5. GAS SAMPLING VALVE 12.a.b.c.d HOKE ON-OFF VALVES

6. PENNING GAUGE HEAD 13a.b NEEDLE VALVES

1 VACUUM GAUGE ( 0 - 7 6 0 mm) 14 & 15 GAS INJECTION PORT

8. COLUMN OVEN 16. BALL VfcLVE

FIG.5. SCHEMATIC DIAGRAM OF D C . ARC EXTRACTOR GAS ANALYSER

vjl

?

a>m

mxo

oo

o

RECORDE RESPONSEg

-52-

00. The evolyed gases are now allowed to homogenise for 60 seoonds.

Then, an amount 5 oo of this ohamber gas is transferred by way of gaa

sampling valve into the chromatogxaphie column (8) (5 feet Linde

molecular sieve 5 A, heated to about 120°C), wherein a separation

between the constituent gases occur, whioh are subsequently deteoted

by the tritium ionization detector (9).

The limits of detection are « 0g and Ng - 10 /l g and

with a standard deviation of 10$. The limits of detection for 0£ oan be

improved by reducing ohamber blank whioh comes mainly from 0- impurity

in argon and blank due to chamber walls. Attempts are being made to

reduce these blanks.

(•Present address j Institute for Atomio Eesearoh, Iowa State College,Ames, Iowa, USA.

1. Monte Evens and V.A. Faasel, Anal. Cheu* £5., 1444 (1965)2. A.P. D'Silva, P.K. Wahi and S.S. Biswas, BARG-336, 19663. A.P. D'Silva, P.K. Wahi and S.S. Biswas, BARC-337* 19^84. M.M. Shahin and S.R. Lipsky, Anal. Chen. , 467-74 (196?)5. A.P. D'Silva, P.K. Wnhi and 3.S. Biswas, BARC/3PEC/C-23, I96B

2* Determination of 0» and N in Argon

(P.K. Wahi and S.S. Biswas)

Trace amounts of oxygen and nitrogen in argon cannot b*

determined using thermal conductivity (TO) detector as these is a vesty

little TC difference between them and argon. As 1he detector mentioned

in the previous seotion is quite sensitive to oxygen and nitrogen, it

was deoided to develop a method for the trace analysis of O- and B In

argon. This can be done provided the reference (carrier) argon oan ba

-53-

pu?Lfiad and aoaa rafereno* atandazda oan 1>a icepacad. fork ia in

progscaa tovarda attaining tooth thasa go&La. PvalisdnaEy Kcperiatat*

ia.ro anoan that I t will be posatbls to aehiara a Halt of datcotion of

0g • 5 PPai and Hg • 10 ppau

-54-

II. ATOMIC. MQEBQIHAR AMD SOLI1>»8IATE SEECTBOSCOFT

Baalc research carried out In atomic spectra concerns mostly

the hyperflne structure and isotope shift studies of rare-earth atoms,

like Nd and Gd. High resolution Fabry-Perot interferometers and grat-

ing spectrograph8 are specially designed and fabricated for a study of

their fine structures In detail* Solid-state spectra relate to the

absorption and fluorescence spectra of rare-earth ions in crystal

lattices and the luminescence spectra of alkalihalides at low tempera-

tures.

High resolution electronic spectra of free radicals produced

in flash photolysis and flash discharges and photographed on large

grating spectrographs are studied for their rotational fine structures*

Laser sources are set up for doing experiments on level crossings and

double resonance techniques in order to achieve very nig*- resolutions

which were hitherto unattainable in optical spectroscopy.

Vibration-rotation spectra of benzenes, pyrimidines and

other molecules are studied in order to understand their molecular

structures* Normal co-ordinate analysis of several of The molecules was

also made to help the assignment of fundamental vibrations* Computer

programmee for fitting observed spectra with band parameters and evalua-

tion of time-correlation functions and band moments have been written

and tested. The programmes enable one to do quantitative analysis more

accurately as well as study the motion of molecules in condensed systems*

molecular interaction in liquids and solutions and factors affecting

shapes and shifts of vlbrational bands*

ATOMIC. MOLECULAR & SOLID STATE SPEC5R0SC0FT

(a) gyperflne Stracture & Isotope Shift Studiesin Atomic Spectra

(d) ^Electronic Spectra & Structure of"Free Radicals & Simile Molecules

l ie. G.D. Saksena SBDr. P. Haoakoteswara Rao , D~.A. Ahmad SD2A. Tenugopalan SA(B)

(b) Speotra of Rare-Earth Ions in Crystals

Dr. B.C. ITaikK. Harihora Ayyar

(o) Solid State Spectra

SD2SC1

Dr. J . RanaaartLH.P. Karanjikar

SD2SC2

Dr. N.A. Naraeinihaa ?Dr. S.LolT.G. Erishnanachari. SDr. P. Ranakoteswara Rao ' DDr. Mahavir Siagh. CDr. V.A. Job CD r . Go TinlcaVniH wyTajoyw^ QDr. M.N. Diz i t CDr. (r. KrishnanusiT- SD2

( e ) Vibrational Spectra & MolecularStructure

Dr. V.B. Kartha DDr. Ch.VeS. Banaohandra Rao CN.D. Fatal SD2Dr. T.A. Sanaa SC2

I

-56-

I I ( a ) , KHERFIHE STRUCTURE ABB ISOTOPE SHIFT STUDIES IN ATOMIC SPECTRA

1, Recording Fabry-Perot Spectrometer (REFPOS) * Some RecentModifications

(<J.D. Saksena and S.A* Ahmad)

The design and fabrication of the Recording Fabry-Perot

Spectrometer (REFPOS) was published earl ier • Recently some a l t e r a -

tions and modifications have been incorporated in order to improve the

versati l i ty of the instrument« These are being briefly reported below.

(a) The twin-hollow cathode system has been replaced by a

multiple hollow cathode assembly which consists of five hollow cathodes.

In the ear l ie r system the optical system was fixed and the hollow

cathodes were brought in position. In the present system the hollow

cathodes are fixed and there Is a moving optical system. Radiation can

be selected from any of the cathodes in matter of seconds and the system

enables to excite standard and samples (e.g. for isobopio analy?.!-;- ot

Li) simultaneously and record them alternately.

(b) The limited few hundred Angstrom scanning range of the grating

monochromator of REFPOS has been replaced by a continuous worm and gear

drive. The scanning speeds can be continuously varied from 1 A/mia "to

64 A/mdn or store. A mechanical counter has been attached to the

grating drive for wavelength identification and i t i s found to be quite

reproducible.

(e) A pick-off mirror has been introduced just a t the exit s l i t

of the monochromator of HEFPOS. A mbtorised drive has been attached to

this reflecting mirror. With the help of t h i s drive the mirror can be

moved In and out of the l ight path by switches provided on the control

-57-

(d) A photomultiplier was placed at right angle to the exit

slit and an amplifier and recording system attached to it. This make a

the grating manoohromator of BEPPOS an independent unit which can be

used for medium resolution work. With slits of IOOJLI , it is possible

oto record lines 0.2 A apart in the 4th order of grating (15,000 lpi,

biased for 1.6pm).

These modifications help in recording the line of

interest under low resolution and within 30 seconds (the time taken by

pick-off mirror to be out of the beam) the line can be scanned through

Pabry-Perot Interferometsr under high resolution ( —10 ) . This haB

considerably reduced the time taken when a large number of l ines are to

be investigated for hyperfine and ieotopic structure investigations•

1) "Setting up of Recording Pabry-Perot Spectrometer" (BEPPOS),BAEC-290 (1967) - CD. Saksena and S.A. Ahmad.

2* Isotope Shift Measurements In Neodymiua

(S*A* Ahmad and G.D. Sakaena)

Isotope shift measurements in spectra of ffd involving i t s

even isotopes was f irst reported by Klinkenberg and subsequently been(2-a)

•tudied by other authorsv ' with a view to find the relative isotope

shift end to isolate field shift and specific mass shift.

Hasan*1 ' has raade a survey of the isotope shift Measurements

in Sd and the author pointed cut correlation between measured isotope

shifts in a-toBio l i s s s and the configuration involved in the transitions

for these l ines . Rao et « l ' 1 1 ' iwrestigated 51 lines between the region

9200-5900 A almost e l l of them belonging to MI epeetnu £hey confirmed

soas configurationa for tha levels involved in the transition of these

II-58- §

lines. Vfyart has also made a mention of the relation between B.&>?

• ' " - /

isotope shift and configuration* i

The present investigation of isotope shifts in the atonic "

lines of Ndl and Ndll has been undertaken with two objectives. Firstly, g

to find isotope shifts for already classified lines in order to bare |

Bome check on the configurations suggested, and secondly to provide %

data on the isotope shiftB for unclassified lines for those engaged in f

extending the present classification of atomic spectra of Nd.

The isotope shifts have been recorded in 306 lines of Hdl tad

Hdll between 3900-4750 A. Out of these 147 lines have been classified ;

by Hasan and flyart. Out of 306 lines investigated by the authors f

isotope shifts data on earlier neaaurements are available only for 23 |

lines* :

Xhe above investigations were carried out on Recording

Perot spectrometer assembled in our laboratory^ • Tha eouroa m sliquid-air-cooled hollow cathode employing current between 16 aA.

32 mit the carrier gas waa He at 2*5 ma of Hg. The grating spectrua

recorded in -the 4th order of the grating (15.000 lpi ruled over 10n x 4fi

area and blazed for 1.6jD>n)* The Pabry-Perot plate optical flats were

A/100 coated far aaxiinum reflectivity at 4300 A*. Spacers of 10 im and

26 mi were used. All the lines were recorded with entrance and exit

elite of 100^» width for monochrooator record and the aana slit widtha

were used for recording the lines through Pabry-Perot interferometer.

Plrst the iaotoplo atructuree were recorded with natural aaa-

pla of neodymiuB which ooneiata of five even-even laotopea (Z • 60,

A'- 142, 144, 146, 148 end 150) and two even-odd laotopea (A - 143 and

-59-

145). All the lines were then inreetigatod -Kith a single isotope of

Id (A - 144) with 94.4$ purity. Thin wan done in order to establish

whether the lines in question were single l ines or close doublets

and h e l W in great way for analysis of the struotura recorded with

natural samples. It was found that many l ines reported by earlier

workers as single were actually dose doublets when recorded with a

single isotope* The earlier workers had obtained spectra using

natural samples of Nd. It was also found that some of the l ines

reported by fhea as doublets, ware aingla linee showing large isotope

shifts.

For lines showing large isotope shifts , measurements of

AD (142Hd - 144Hd) were Bade using a 4i3 mixture of enriched 142Hd

(96.245Q sad 144Hd (S4.47£). ?cr lines showing small isotope shifts

we measured AD (U2Nd - 146Hd) using 1iO*7 mixture of 142ffd (96.2£3)

and i46Nd (96.2$)* Prom these measurement AD( 1 4 2 id - t44ffd)wae a?o-

urately deduced using relative isotopie shifts position.

Out of the three hundred and six l ines belonging to Sdl eed

Hdll studied} 109 lines show appreoiaMe isotope shifts. Hie isotope

shift Ai>(142Nd - 144Id) varies between 0.010 em"1 and 0.100 cm'1.

Using these data, confirmation of the lerel configurations suggested

for classified lines and also suggestions about new configurations here

been » d e . Isotope shift raluee for different energy lorels of V4I a*4

Mil hare been also obtained and Ibis will be holpful in furtjaer cla-

ssifloatioB of Hk% speotra ef neodymium.

-60- |

References

1. KLiakenberg, P.F.Aj Phyaiea II (1945) 327 •• i

2. Noldeke, G. and Steudel, A., Z. Fhys. 121 (1954)f 632 j

3. Noldeke, G, Z. Phye. J4J, (1955), 274 j

4. Korolev, P.A. & Oaipov, I.P. Dokal. Akad. Nank, SSSB JJO (1956), 365 |

5. Blaiae, J. Annl. Phys. 1 (1958), 1019

6. Dontsov, Y.P», Morozov, T.A. and StraginoY, A.E., Opt. ft Speot. 1J

(1960), 391

7. Gerstenkorn, S, Helbert, J.M., and Chabbal, B., Coopt. Rend* 261

(1965), 1932

8* Hansen, J.E., Steudel, A. and Walther, H., Z. Phys (1967), 296

9. Comanidu E., Rev. Roum. Phys. J£ (1969) 6O3j J£ (1971) 527

10. Hasan, Q.E.M.A., "The Atomic Spectra of Ndl and Ndll" - Thesis,

Austerdam (1962)

11. Rao, P.R., end Gluck G., Proc. Roy. Soc. A 2JJ, (1964)S 540

12. flyart, J.P., Thesis, University of Paris (1968)

13. G.D. Sakeena and S.A. Ahmad, BARC/190 (1967)

3. Isotope Shift Measurement la Gadoliniua

(A. Yenugopal, S.A. Ahmad and G.D. Saksena)

Ihe knowledge of isotope shift in a spectral lia« proridea

Information about Hie oonfigurationa of the levels inrolrsd In 1l»e

transition* With this In new, it was decided to record isotope shifts

In a large number of spectral lines of Gdl and Gdll. It is of considera-

ble interest in recording 1he isotope shift between the rare isotope

152Gd (natural abundance 0.2$) and 1540d (natural abundance 2.155Q.

i52Od has (H - 88, 2 - 64) and 154Gd (V « 90), Z - 64) and an aoonrat*

-61-

knowledge of isotope shift, will throw some light on nuclear deforma-

tion and help in calculation of nuclear deformation parameter.

The grating spectra using the grating nonochromator of

oBBEPOS was recorded between 3900-4750 A. The source was a liquid-air-

cooled hollow cathode using natural samples of Gd a3 S ^ V ***k &

hollow cathode current of 32 nA and neon as the carrier gas at a pre-

ssure of 2.5 mm of Hg.

From thiB record 350 lines of Gdl and GdIX h&ve bees ides-o

tified. Out of this , 5$ l ines between 3900-4200 A hava been recorded

on the HESTOS UBing a spacer of 28 mm* !Ehe Pabry-Perot plateB i&ich

are flat to A/100 are coated for —*<"• reflectiTity at 4300 A.

For the first tine we hare been able to repcrs negative

isotope Bhift. in the spectral l ines of Gd* Earlier this co-old not bo

detected as l ines showing negative isotope shiftB ars "

photographic methods are usually inadequate. The

shifts range between 0*035 cm"" and 0.075 cm" .

lines of Gdl and GdXI using enriched ieotopic samples oi QAV avj in

progresso

-62-

II (b). SPECTRA OF BAHE*EABTH IOHS 15 OBYSTAIS

1. Absorption and Fluorescence Spectra of Hare Earth Trichloro-aeetates

(B.C. Balk and E. Harihara Ayyar)

Absorption and fluorescence spectral studies of certain rare

earth trichloroacetates was undertaken as part of our general progra-

mme of spectroscopic investigation of crystalline compounds of rare

earths. Though several people have worked on the chemical and

thermal behaviour, crystal structure by x-ray method, molecular stru-

cture and infrared spectral studies, no absorption and fluorescence

spectral studies have been reported on these complexes to date*

Trichloroacetates of Eu, Tb, Pr and fid were prepared and

single crystals were grown from their aqueous solutions. Absorption

and .fluorescence spectra of Eu and Tb trichloroacetatas and absorption

spectra of the non-fluorescing Pr and Nd-triehloroecetatee *ev$ wear*

ded at 77 °K on a three prism steinheil spectrograph usiEg sie&ius optic**.,

The results of the analysis of the spectra can be

summarised as followsI-

1) The site symmetry around the rare earth ion In these

complexes Is very low as there appears to be a complete removal of

J-degeneracy (except Kramer's degeneracy In oases involving odd electron

configurations) for most of the observed J-levels . Complete removal of

J-degeneraey of the J-levels i s possible in C^ 0 ^ Oj, C ^ , 0 end »

eyaoetrles.

2) Zhe number of observed transitions 9 on the oliier band la

*»' \ ~ * \ <** *»t \ - + \ further suggests that the

-63-

around the rare earth ion is likely to be C .

3) Fluorescence intensities in Tb, and Eu-triebloro-

acetates point out that they are weakly fluoreaing substances.

is further seen from the fact that only the D level in Eu-5

trichloroaoetate and D. in Tb-trichloroacetate fluorescence. In4

other strongly fluorescing chelates unless the chelate absorption5 5 5

masks, other higher levels l ike D,., D- and even D, in Eu-cooplexec5 5and D-i D_ etc. in case of Tb-complexes also fluoreBce.

4) No ligand absorption is found in the visible aad nearo

ultraviolet region and i t starts only below 3000 A*

5) In the anhydrous state a l l the four rare earth trichloro-

acetates gave very broad absorption bands* Further, unlike other

anhydrous crystalline compounds no fluorescence was observed from Nd

end Fr-trichloroacetates. The Eu and Tb triehloroacetates gave very

broad fluorescence, lacking any Internal structure. Mils suggests that

the anhydrous compleiee lack crystallinity as they cannot arrange into

a regular la t t i ce .

Further work to record the spectra with higher dispersion

and resolution in order to locate al l the energy levels and to cal-

culate the Slater parameters In ease of trihydrated Hd-trichloroaoetate

is in progress.

2. k Hew Biase of Bare Earth Trichloroacetatea with Two Moiecsileaof Water of Hydration

(B.G. Raik and E. Harihara Ayyar)

It i s reported that rare earth trichloroacetates crystallite

with three* noleculeB of water of hydration which are lost to give the

- Q 4 -

correspondine anhydrous complexes nben heated at 60°C or kept in a

vtiouun desicutor for 4U hours over PgOe* Thus °«ly '^o phases via,

the trihydrated and the anhydrous were known from previous studies en

these complexes. But during the course of a epectroecopio Investiga-

tion on some of tbo trihydrated rare earth trlchloroacetates there was

an indication that there exists a new phase for these complexes with

an intermediate state of hydration. The present study was undertaken

to Investigate this aspect more completely. The clue to this was

obtained from the appearance of extraneous l ines in the spectra of some

trihydrated samples particularly in those samples which were stored for

long periods after preparation* Obviously the extraneous l ines did not

belong to the anhydrous phase which gave broad band spectra.

It was possible to prepare samples of Eu and Hd-trichloroace-

tates which gave an entirely new spectrum containing the extraneous

lines mentioned above. This was done by heating single crystals of the

corresponding trihydrated complexes at 50dC under vacuum. Solid stste

absorption and fluorescence spectra were thus used to label the

complexes. A determination of the water of bydration of the samples

giving the new spectra showed that they belonged to the dihydrated phase.

As the difference in activation energies to remove the f i r s t water mole-

cule and the remaining two water'molecules i s not large, attempts to

prepare a pure dlhydrated sample resulted In mixture containing traces

of trihydrated or the anhydrous phase depending on the period of heat-

ing. But as the anhydrous samples give groups of continuous broad

band Bpectra, samples containing traces of anhydrous phase posed no

3 < I - ' • ' • ' %

• <

S /2 7 /24F,

VA

FIG. 7 ABSORPTION AND FLUORESCENCE SPECTRA OFEu AND Nd TRICHLOROACETATES.( 1 . 2 , & 3 CORRESPOND TO THE SPECTRA _O_F TRIHYDRATED

-65-

problem and it.was possible to prepare such samples to study the

spectra of dihydrated phase.

The dihydrated and the trihydrated samples of a l l the rare

earth trichloroacetates which were studded gave sharp l ine spectra "

which were entirely different from each other in the two Btates of

hy drat ion. Fig.7 shows a few of the selected absorption and fluores-

cence groups for Eu and Nd trichloroacetates« The dihydrated sauries

gave a multiplicity of lines for al l the groups, generally twice as

many as are allowed for any single chemical species. This i s believed

to be arising due to the presence of two structural isomers In case of

the dihydrated rare earth trichloroacetates*

Further evidence to show the existence of the dihydrated

phase came from thermogravimetric and infrared spectral studies on Nd-

trichloroacetates» Previous thermogravimetric studies by Mathur

however, did not show up the existence of the dihydrated phase*

ever, in his studies the experimental conditions such as the rate of

heating and the amount of sample taken were not favourable for good

resolution needed in the present studies.

It is also found that the samples giving absorption spectra

different from those of anhydrous and trihydrated samples, also give

an Infrared spectrum which have some additional frequencies by which it

can be distinguished from the trihydrated and anhydrous phases.

(1) Mathur, B.S., Studies on Hare Earth and Yttrium Complexes ofSome Mono and Dibasic Acidst Hi.D. Sheeis, Bombay University,1967.

-f-. fi-

l l ( c ) . SOLID STATE SPECTRA

1. Design and Fabrication of Equipment for the Study of Absorption,Reflectivity. Emission and Excitation Spectra at low Temperatures

( j . Bamamurti)

A glass liquid nitrogen cryostat has been fabricated with

facility for both immersing the sample and for varying the tempera-

ture. Prevision is made for rotating the sample in and out of the

radiation beam. A metal liquid helium cryostat has been designed and

submitted to Central Workshops for fabrication. In this also

provision, is made to have the sample either in vacuum or in liquid

helium and to rotate the sample in and out of the radiation bean, with-

out disturbing the vacuum* A glass liquid helium cryostat is being

fabricated with locally available glass tubing in the divisional glass

shop.

To measure absorption spectra, the Hilgsr single fciam

spectrophotometer has been modified to take a sensitive photo-

multiplier instead of a photocell. Three monochromators for the aar-

visible region have been fabricated. All are based on the Czerney

Turner mounting and have sine drives. The focal length of the colli-

mating mirror and focussing mirror are equal. The focal length of the

mirrors in two monochromators is 1/4 meter and in one the focal length

is 1/2 meter. The quarter meter ones can take gratings of two sizes,

2" x 2" and tj" x 1". The half meter one takes a grating of 2" x 2"

size. For work at higher energies it is proposed to fabricate a vacuua

ultraviolet monochromator and the basic design features of this have

-67-

been finalised. It will be a mounting in which concave grating

mores on a Rowland circle. Radius of the concave grating la 20.03 cm.

The angle of incidence and diffraction in zero order is 10°. The de-

tailed design is under progress* Besides this, a photomultipller

attachment for the 3 meter Hilger vacuum uv speotrograph has been

fabricated. Besides the above, a ur-vislble monochromator with different

grating and mirror mountings has been designed.

Adjustments of monochromators for exact reproducibility la

one of the main factors in the use of the Instruments. Two important

adjustments In a sine drive are -the length of the lever and the •tart-

ing position of the lever. Computation of the magnitude of the error

for any one of the two mlsadjustments have been made. If AL is the

change In length and Lc is the correct length of the lever, then AA

change in the output wavelength is

_v -£k _x (£±) + etc.

where X i s the correct output wavelength for Lo- Another similar

expression for the change in the output wavelength as a function of the

error in the angle setting, has been obtained and values computed.

2. Imminisoence of Pure and Mixed Alkali Halidee Osl. KClsKBr.HaOltHaBr

( j . Banamurti)

Irradiation of single crystals of alkali halides gives rise

to luminlBcence at low temperatures. This can be due to impurities,

in which case It i s host sensitised luminiscenoe or i t can be due to

-60-

crystal latt ice itself in which case i t ia termed as intrinsic lumini-

ecence . The latter should be Independent of the history of the

samples studied* Also Intrinsic lumlniscence should be stimulated only

in the fundamental absorption region of the crystal. Csl gives rise

to several emission bands on Irradiation in the region between 5*4 and

10 eV. The peaks of these emission bands are at 4-35» 4«2O, 4.06,

3*64, 3.35, 3.06 and 2.64 eV. Of these only the 3.64 eV emission i s

stimulated above 5.8 eV as shown In Pig.8. This i s excited only in the

fundamental absorption region and hence one can conclude that i t i s an

intrinsic emission band. The 4.06, 3.35, 3.06 and 2*64 eV emission

bands are utimulated outside the fundamental absorption region as

shown in FigoS and hence i t can be concluded that these are due to un-

intentional impurities in the crystal. The 4*35 and 4.20 eV emission

bands are stimulated bo1£ outside the fundamental absorption region ess£

in the fundamental absorption region. This pen *?•* «??n ij '• . '-^-'Hrv*

the crystal with 5.5 eV photons but not in thfc ©so A-,.-tier: =;>••* ^?s sin?*

the 4.06 eV impurity band masks them. The relative invensitv s.r the2»

two bands changes with respect to the 3.64 eV emission in two different

crystals studied. The excitation spectra of these bands i s similar to

that of the 3*64 eV emission in the fundamental absorption region. The

strong excitation of the impurity emission in the host absorption i s

explained by assuming transfer of energy to impurity centre from the host.

Hence we attribute both 4*35 and 4.20 eV bands to Impurities in Csl.

The above results on Csl indicate that luminiscenoe of single

crystals of alkali halidea are sensitive to unintentional impurities ija

- 6 9 -

,2400 2000 1800 1600 1400

50 60 70 80EENERGY IN eV

90

FIG. 8. a ) EXCITATION SPECTRUM FOR 3.64 eVEMISSION BAND OF Csl. b) EXCITATIONSPECTRUM OF IMPURITY EMISSIONBANDS. DASHED LINE SHOWSABSORPTION DUE TO A SINGLE CRYSTAL.

-70-

the crystals* Alkali chlorides, KC1 and NaCl contain large eonoen-

(2)tration of bromineN ' and in this case it 1 B difficult to distinguish

impurity emission from intrinsic emission since the absorption of

brotriue is very olose to the exoiton absorption of NaCl or KC1. So

the emission and excitation spectra of NaOl aad KC1 intentionally

doped with Br have been studied. The Be are shown in Fig*9« The 5»35

and 3*92 eV emission bands vary with concentration of bromine and

hence are due to bromine. Only the 3*99 eV band is intrinsic* The

peaks in the excitation spectra of these bands fall on the long ware-

length tail of the first exciton peak of NaCl which is similar to the

excitation spectra of the impurity bands in Csl. It should be noted

that we are monitoring the very low level absorption due to the bromine

impurity center by looking at the emission due to these centres* This

absorption would normally be very difficult to measure directly since*

it would be masked by the host crystal absorption. This ia a r<2*T'ffe-

tation of the general phenomena that luminescence is a Terr &s.i»'tir^

test of presence of impurities. In KGltKBr 3 emission bands ere ©

with peak position at 4.91, 3.63 and 2.43 eV. We attribute all the

three to the bromine impurity.

(1) J. Ramamurti and K. leegarden, Ehys. Rev. V&, 698 (1966)(2) K. Koboyashi and lomiki. J. Ihys. Soc, Japan, Jjj,, 1982 (i960)

-71 -

7-6 78ENERGY IN

FIG. 9. EXCITATION SPECTRA FOR a)3.49eV ti 3.92 eV ANDc)5.25eV EMISSION BANDS OF Nacl:Br d)EXCITONSPECTRUM OF THIN FILM OF N a d e) ABSORPTIONSPECTRUM OF A SINGLE CRYSTAL OF Nad (SCHEMATIC).THE SPECTRA ARE MEASURED AT 10#K

-72-

II (d). ELECTRONIC SPECTRA AND SJRUOTPBE 0? PHEB RADICALS AM? 3]MQEECOIBS

*« Near Infrared Bands of 3_

(H.A. Naraeimham}

o

Fragmentary bands observed in the region 6900 - 8100 A in

emission from a microwave discharge through sulphur vapour with heliua

as a carrier gas, have been shown to be due to S_ and to involve

transitions from a common initial state TT to A and I , states*g u u

The TT is an inverted state and has a spin splitting of 134 cm" •

The sub-states, TT and TT predissociate at J1 fc 34 and J1 >/ 16respectively while the TT state is not observed* Detailed

oganalysis of the rotational structure of "the bands shows that the bands

° P Q_at 7506. 7785 and 8083 A have, in each, six branches Q,.-* "-to*

12* ^13* E13 P13 c o r r e eP° n dl nS "«o transitions from F,, levelsof TT to P- and P- levels of E state while each of

Zg 2 y Uo p g

at 7434. 7707 and 7996 A shows three branches H^t Sj 1 «oAcorresponding to transitions from £> levels of TT. to P. levels ofz - ig i

the 5 I state* The lower state,- 'Z *, i s considered as a transitionu

to Hund's coupling case (c).

2« Spectra of Molecules of Interest in Air Pollution StudiestRotational Analysis of the 3000 & Band System of SO-

(S«L.R*Q-* Eriehnamaehari & T.?. Venkatachalaa)

Sulphur dioxide i s one of the atmospheric pollutants vhich

plays an Important role in the photochemistry of the pollvted atmos-

phare. As the solar radiation transmitted Into the lower ataospher*

-73-

Us

O

to

oo

oI

o

u.

-74-

ohas a lower wavelength cut off at 2900 A, the transitions that are of

interest in the SO molecule are the a B. - X A1 transition repre-

senting the 3600 A system and the A ( B.) - X A. transition repre-

senting the 3000 A system. Of these the former is forbidden by

electric dipole selection rules and it is the latter transition which,

is responsible for the initial photoexcitation of the SO molecule.

However, in spite of its importance t the electronic epecias classi-

fication of the upper state (A) of this system, the vibrational

assignments of the bands and the determination of the geometry of the

molecule in this state have not been satisfactorily done* Hence a

systematic study of tills system of S0_ is being undertaken in our

laboratory.

The fairly extended nature of the band system, from

0

2600 - 3400 A indicates that the molecule undergoes a large change ia

geometry on electronic excitation« As a resralt; several 4U-"M»*»». *if tfc<?

bending and stretching vibrations of the melseuLs art 'xa1?**?*?. ?.?sd

bands belonging to tiaese transitions strongly overlap. Because of

complexity, i t becomes difficult to locate the origin of the band

system and make an unambiguous assignment of the vibrat ions! quantumnumbers of the bands* In order to make a correct vibrational assign*

16 18ment of the bands, the spectra of the isotopic species S 0., 8 0,

16 1fi

and S 0 0 are being studied. The enriched SO. is prepared by burn-

ing sulphur in 18Q enriched oxygen gas. Prom a Btudy of the vibra-

tlonal isotope shifts I t has been possible to arrive at the correct

vibrational numbering of the bands.

-75-

The vibrational structure of the band system gives a quali-

tative information about the geometry of the molecule in the concerned

electronic states. Quantitative information about the geometrical

structure could only be obtained from a complete rotational analysis

of the bands. In the case of SO- whe«. the principal moments of

inertia are fairly large, one requires instruments of very high reso-

lution to resolve the rotational structure completely*

However, by studying the structure of the contour of the

band which involves the study of the K-structure, it would be possi-

ble to arrive at a reasonably accurate geometrical structure of the

molecule* The K-structure could be resolved with instruments of

moderate dispersion and resolution. Certain bands in the spectra of

16 18 16 ISS 0,|3 0- and 8 0 0 which are free from overlapping are chosen

ofor such band contour study. The bands at 3040 A which represent

340 - 000 vibrational transition are photographed in the 3rd and 4th

orders of the 3*4 metre Ebert Spectrograph at a dispersion of 0-3 A/wst

end 0.6 A/nm respectively. The measured K-structure is compared with

the computer simulated one obtained by giving different values for

the bond distance and the bond angle. She preliminary results ob-

tained from the analysis of the contour of the S 02 molecule indicate

that in the excited state (l), the bond distance increases from the

ground state value of 1*43 to 1.52 while the bond angle decreases from

the ground state value of 119.5° to 106°. These values are being

improved to fit the observed contours of the S 0g end S 0 0 moleeuUs.

-76-

3. Electronic Spectra of Some Substituted Aaabenzenea

(V.A. Job and ScB* Kartha)

The electronic states of Azabenzenes have been studied in

great detail; both experimentally and theoretically* A summary of the

work done till 1966 can be found in a critical review by limes et al* .

A spectroscopic investigation of substituted azabenaenes would be of

great help in clearing up some of the present ambiguities regarding

the vibrational assignments and excited state geometrical structure of

the parent molecules* We have studied-the vibrational and electronic

spectra of several substituted azinee, and a summary of the results is

given below.

(i) K.K. Innes, J.P. Byrne and I.G. Ross; J. Mole* Spectroecopy22, 125 (1967).

(a) Ihe Electronic Spectrum of Dimethyl Tetrazine

Dimethyl tetrazine vapour exhibits handed absorp1&<si

ctrum in the region 5900 - 5200 A* The strong band at 17496 cm has

been assigned as the 0-0 band. A strong v* progression of 519 en! is

observed and this has been assigned to the mode A) 6a* (The conventions

used here are the same as those in the review by Innes et al (ioc.cit)*

A band observed at 520 cm" to the red of the 0-0 transition Is

assigned to the corresponding 0-1 transition-. Almost all the bands

in the spectrum could be assigned in terms of four excited state vibra-

tional frequencies, 519 em f 835 cm" , 1287 cm"1 and 1482 <aa"\ These

have been assigned to the modes V 6a, ^ 1 , ^12 and ^8a, which corr-

espond to the totally symmetric ag modes of s-tetrazine, thus Indicating

-77-

that the D^ symmetry for the ring i s not appreciably altered by

methyl substitution. Two sequences of +55 and -100 cm"1 were identi-

fied in the spectrum. In the absence of the corresponding 0-2 and 2-0

bands i t i s not possible to make definite assignments for these

sequences; these, however, can be tentatively assigned as the 1-1

transitions of lJ16v, and \J.. respectively, as these two sequenciea

are prominent in the spectrum of s-tetrazlne.

As we have no information about the ground state geometry

or rotational constants of dimethyl tetrazine i t would be rather

difficult to obtain good values for the rotational constants of both

upper and lower states simultaneously by fitting the partially resolved

rotational structure by hand contour techniques. However, we were

interested to see whether the structural changes of s-tetrassine on ele-(2)ctronic excitation proposed by Merer and Imes would reproduce at-

least the gross features of the experimental contour. A trial set of

rotational constants were obtained by assuming the structures proposed

for the Ag and B_u states of s-tetrazine. The internal rotation of

the methyl groups was neglected* She C-type contour computed with

these constants reproduced the gross features of the experimental con-

tour. In the experimental contour a strong sharp red degraded B^ head

and on the violet side of the head weak partially resolved structure

(B_ heads) are seen* These features are sensitive to the change In the

rotational constant A. A larger value for A would have resulted in a

sharp turning back of the IL heads* Thus* the structural change pro-

posed for s-tetraaine i . e . a slight elongation of the ring, teems to be

-78-

coropatible with the observed band contour of dimethyl tetr&zine.

(2) A.J. Merer and K.K. Innea, Proc. Roy. Soc. A. ,202, 271 (1968)

(b) Ths Electronic Absorption Spectra of 5-Methyl Pyrimidlne and4-Methyl Pyrimidine

The ultraviolet absorption spectrum of 5-methyl pyrimidineo

shows discrete bands In the region 3500-2900 A. This i s the ana-

logue of the B. - A. (TT-*-n) transition in the parent molecule,

pyrimidine* The strong band at 30800 cm** was identified as the 0-0

band* A v1 progression of 530 cm" and v" progression of 557 cm"

are the most prominent features in the spectrum. This has been

assigned to the vibrational mode ^ 6a* The other progressions .

1 \'' —1 1'observed in the spectra are -816 cm" ( ^ 12) and + 785 cm ( ^ 1 2 ) .

- 1

In addition strong bands are observed at + 1020, + 994 and - 1047 cm

from the origin and the members of the V 6a and ^12 progressions.

These ore assigned to ^ 8 a , VJ and \) 1 respectively. !5eo!.".u^*s cf

-159 cm" and -268 cm" were assigned to the 1-1 transitions ai ^ loa

and ^ 6 b . Confirmation for tha assignment of the V 16a sequence i s

obtained from the identification of the corresponding 0-2 and 2-0 bands—1 —1

at -602 cm and + 466 cm from the 0-0 br. d. All the strong bands in

the spectra could be assigned in terms of the totally symmetric modes

^ 1 , ^ 6 a , ^12 and ^ 8 a and sequences in ^ 16a and 6 b .

The A, B and 0 type band contours were computed with trial

rotational constants obtained from a structure in waich the geometrical

parameters were assumed to be those given for pyrimidine by Innes et al .

The computed contours were markedly different from the observed one*

-79-

The gross features of the C-type computed contours oould be Batched

with Hie observed contour by asking the change in the rotational

constant A very snail ( + 0.001). She structural change suggested

by limes et a l ^ ' for pyrimidine on electronic excitation results

in a auch larger change for A ( -0.01 )• She structural ch&age

proposed for s-tetrasine by Herer and InnesV*' seeas to be sure

compatible with the observed contour of 5-aethyl pyrlaldlno.

The corresponding absorption spectrum of 4-aethyl

pyrtmidine was observed in the region 3250-2800 A. Because of the

lower symmetry of 4-methyl pyrimidiiie, there i s no restriction on

the number of quanta excited for al l the in-plane vibrations of the

ring. The band at 31609 cm" i s assigned as the 0-0 band. Hot bands

are observed at displacements -623 cm" r -480 cm" r -536 cm"* and

-358 cm" from -the origin and other strong band's. These are assigned

to the modes ^12 , ^ 6 b , ^6a and ^ 18b respectively? ^18b

corresponding to the in-plane C-CH, bending node. A v* progression

of 768 cm" observed In the spectrum i s readily assigned to ^12y

Other strong bands occur in the spectri-m at,displacements of +364 oa

from the 0-0 band and each member of ttie +768 on" progression and at

+540 cm"1 and 559 cm"1 from the 0-0 band. Biese are assigned to the

modes ^I8b, ^ 6a and ^6b respectively. Unlike most of the

azlnes and substituted asines a long progression in \) 6a i s not ob-

served la "the spectrum of 4-methyl pyrimidine. Confirmation for the

assignment of the mode ^ 18b i s obtained from the fact that the

•364 interval Is also observed In 2-aethyl pyrazine and 2,6-dimethyl

-80-

pyraelne, flbere the C-CB_ bending mode i s totally symmetric as l a

4-ae'thyl pyrimidine.

(3) E.K. Ianee, E.D. MoSwiney Jr . . J.D. Simoons and S.O. Silford;J. Kol. Speetry. 2h ™ (1969).

(c) Electronic Absorption Spectra of 2-methyl pyraxlne.

Ihe UV absorption speotra of 2-methyl pyrasine, 2,6-dimethylo

pyraaine and 2,6-dichloro pyrazlne occur in the region 34O0-3OGOA*

She analysis of these band systems i s yet to be completed.

The 0-0 band of 2-methyl pyraalne appears at 30948 CB .

She Tibratlonal frequencies identified in the spectrum are 928 em

( ^ 1 ) , 637 em"1 ( ^6b), 560 cm"1 ( ^6a) , 357 cm"1 ( ^18e),

567 cm"1 ( ^ 6 a ) , 628 cm"1 ( ^6b) and 898 cm"1 { ^ 1 ) .

The 0-0 band of 2,6-dimethyl pyrasine occurs at 31161 om. «

She vibratianal frequencies 602 cm" ( ^ 6 a ) t 551 cm" ( ^6a) and

365 cm"1 ( ^9a) were identified in the spectre..

The origin of the transition occurs at 32967 om in the

electronic absorption spectrum of 2,6-dichloro pyrazlne. l-jiis Tibra-

tional frequencies identified in the spectra are 177 enT1

172 cm"1 ( V 9 a ) t 558 cm"1 ( ^6a) and 461 CM"1 ( ^ 6 a ) .

4» Emjaelon Speotrum of PrO

(H.A. Sarasimhamy 0. Kriehnamurty and T.7. Venkatachalaii)

The bands of the diatomic molecule PrO ware exclt«d la d.o.

are using carbon electrodes fed with pure ^0.^ powder and metallic

- 8 1 -

B M resulting spectra emitted from the arc were photo-

on a 3.4 mater Jazrel-Aah grating speotrograph (30,000 l i nes /

in the f i r s t order at a dispersion of 2.5 A/m. They were

Into twelve band systems aa per ear l ie r workers. Sinca no

rotational structure analysis for any of these bands are published, a

" ^ J l a d rotat ional structure analysis of some of these bands were

!--'.,rled out.

The 0-0 band at 6488.95 A and the 1-0 band at 7986.44 A of

'.•4~oa I and the 0-0 band at 7662.85 A of system I I I , were photographed

CJI a 6.6 meter concave grating speetrograph (30,000 lines/inch) in the

iUot order a t a dispersion of 1.2 A/m. Tae rotational structure of

-u.-'*3 bands consisted of three branches v iz . the P, Q and H branches

'••••V;U could only arise out of a transition involving A X * ± 1. Cfa

vOJ basis of 1ne rotational analysis these bands were assigned to

'. vaisitions from v1 a Q and 1 levels of A A _ / o and v1 • 0 level of5/2

„ > 2'v. cy- to a common v" « 0 level of the ground, X TTa/2

stat*'

*'•• rteinvestip;ati cm erf the Band Systems of NS

(T.K. BalasubramEinian and N.A. Narasimham)

la recent years, several workers have studied the HS moleeula

'.iii the microwave technique and extremely accurate values for the

-?crational constants of the ground I TT state are now available.

Sbase oonstants werei also known earlier, though1 not so accurately,

from optical speetroecopic data of Zeeman^1' from an analysis of the

0-0 and 0-1 bands of the f -system. The rotational constants reported

- 8 2 -

by geeman do not agree with those obtained from microwave data,

although the microwave data has been confirmed by several Independent

workers. She rotational constants of the I state ( in i t ia l stats

of the V-system) and the & state ( in i t ia l state of the p system)

are known only relative to those of the ground state and a revision

of the ground state rotational constants would necessitate a corres-

ponding revision of the constants of these excited states as well* In

view of these, i t was though necessary to reanalyse some of the bands

of "tiie j3 and the f systems of the NS molecule.

Accordingly, the P and / bands have been photographed on a

3*4 m Sbert grating spectrograph In the third order (dispersion 0*7

A/mm)< Xhe analysis of the 0-0 band of the / sys tem shows that the

2•pin-splitting in the in i t ia l £ state i s not negligible as wassupposed by Zeeman but has a measurable magnitude ( f • 0.0054 cm ) .

2ilso, the centrifugal stretching constant D of the 2 stats had to

o

be revised drastically. Ihe rotational constants derived, after taking

into account the above facts, agreo well with those obtained from mioro-

wave data. Several perturbations In the higher rotational levels of the2

£ state have been observed. To confirm this and propose a possible

mechanism for theoe perturbations, the rotational structure of the 0-1

band i s being presently studied.

( i ) P.B. Zeeman, Can. J. Ihys., 2£, 174 (i95i)

-83-

6. Spin-Orbit Coupling Constant In the A 2 if state of 0*

(G.I. Bhale)

Rotational analysis of the 0-8 and 1-7 bands of the second

negative (A n"u - X TTg) bands of 0 g revealed that the upper state2

A ITU i s an inverted state and not a regular one as has been aesvmed

so fax* She revised value of the spin-orbit coupling constant A' i s

-4.0 as against the earlier accepted value of 46.2.

Xhe 0-8 and 1-7 bands were photographed in the third order of

a 3*6 m Ebert grating spectrograph at a dispersion of 0.65 A/W. An

unambiguous identification of the S> {\k) line In both these bands

showed that the upper state oust be Inverted.

ThiB conclusion i s further supported by Hie intensity pattern

exhibited by the various sets of rotational lines of these bands,

when the observed Intensity ratios are compared with the theoretically

calculated ones, using the two alternate values of A1 in question, i t

i s seen that agreement exists only i f the negative value of A1 Is used

for these calculations, as shown in Fig* 11.

The X -doublings in the various bands of (i6Q180)'t> speetnm

nave further supported these conclusions.

7t Electronic Spectrum of SgO

Sakehminarayana and ZT.A* Narasiahaa) -

She electronic absorption spectrum of SgO has been photographed

en a 3 u grating spectrograph by the so-called 'afterglow1 method using

30

20-

• i

10-

'0-5

EXPERIMENTAL CURVETHEORETICAL CURVE WITH A 8

—••THEORETICAL CURVE WITH As-40

-O-— — -O— -O— -O—O— -O—O-- O— O - -O

4-5 8-5 12-5 16-5 20-5

03P

FIG.11. NTENSITY RATIOS IN THE 0 -8 BAND OF SECOND NEGATIVESYSTEM OF 05

- 8 5 -

hyirogen oontinunm as the teakground radiation* We have photographed

along with i t s previously know absorption tends in the region

2500 - 3400 Af a new eleotronio tend system in the 1900-2300 A region*

(a) Yibrational Analysis of the 2500-SdOO A Banda

Bren though these absorption bands were photographed

previously no vibrational analysis of these tends attributing them

to 6-0 has teen made until now* She wave numbers of these bends have

teen determined by using iron lines as standards. The absorption tends

are arranged into six progressions involving various vibrational modes

in th» upper and in the lower eleotronio states. The vibrational analysis

yielded the following vibrational frequenoieai

upper

1035 <

261 <

state Lower

1165

387

state

-1om-1

-1

y (8-0 Stretch)

j/ (S-S-0 band)

V- (S-S Stretoh)

( B ) Tibrationsl Analysis of 1900-2*00 A Bands

The wave nunters of these tends are. determined using atomic

eopper l ines as standards* She vibrational analysis of these tends

yielded the following vibrational frequencies in the eaoited eleotronio

state*

V t (ft-0) - Vt (3-B-0) - 270 em"1

y ? (8-8) - 378 omT1

-86-

fhla upper eleotronio atate la at a height of 44228 cm* froa the

ground atate*

8. Rotational Analyaia of the 0-0 Band of the D-I Syatea of 8£

^V»A» Barasinihasi

Botatlonal analysis of the 0-0 band at 1700 A of the D-X banda

of Snt photographed under high resolutien, haa been carried out*

Various molecular constants in the D TT u state hare been detexnined

from this analysis. The rotational structure of the higher nembere

of the T H • o progression is found to be diffuse and hence could not

be analysed. Ibis diffuse character is in conformity with the ear-

lier suggestion of the D TT u state being predieeoeiated at higher

Tibrational levels*

9# Bydberg Transitions of Sg

(C.G. Mahajen*, 6. Lakshmlnarayana and N.A. Harasimham)

The second member of the Bydberg transition [-(-IT (3P ))-**

3p)(TTu np)1 haa been photographed in the 1400-1540 A region

under better resolution than that used before* She structure of each

of these bands could therefore be resolved* further work to under-

stand the structure of these bands in terms of the theory of the

Hydberg eleotronio states In molecules la In progress*

i* M S <*zuor Eeeearch Reliant)

-37-

10. Rotational Analysis of the A 5 TT - X £ ~ System of s-0

(N.A. Harasimhem and Kahma Baghuveer)

The rotational analysis of the V^-X and P2«X components of th«

0-0 band lying at 2634 A and 2C23 A respectively and of the P - I

components of the 1-0 band lying at 2595 A and belonging to the

A T T - X 1 ~ system of SO has been completed. Vaxioue moleoular

oonetants have been evaluated from Ibis analysis. The shifts of the

0-0 band heads from the expected position axe found not to be due to

the shift of the first few rotational l ines of these bands.

"81. Plash Photolysis of Organic and Inorganic Compounds

(S.I.N.G. KriBhnamachari)

a) The Mechanism of Formation of Formaldehyde in the RtotochemioalDecomposition of Organic Compounds

Formaldehyde plays an important role in various photochemical

reactions such as In photosynthesis, atmospheric photochemical reactions

In polluted atmospheres and In the photochemical reactions in galactic

end interstellar media. It i s of great interest to determine the rela-

tive efficiencies of the formation of formaldehyde from -the addition

reactions Involving smaller constituents and from the degradation rea-

ctions of bigger cnes. The photolysis of methyl formate provides a

suitable system vberein these two reactions could be simultaneously

studied. Methyl formate has a continuous absorption speotrum below

2500 A nhicn i s favourable for the photocomposition of this molecule.

Hash photolysis techniques coupled with absorption epeot roe copy ore

-88-

•mployed to study this problem. With the help of the flash photolysis

unit that has been built in 1fce Division? the flash photolysis of

methyl fornate baa been studied with the delay time ranging from 5 J<

sec. to 200 p see. and absorption path lengths upto 16 metres* She

formyl radical (HGO) has been observed with the help of i t s absorption

bends occuring In the region 5600-6800 A, as a transient species with

a half-l ife of 100 sec. The occurrence of formaldehyde as a stable

end product was established from i t s absorption bands occurring In

the region 2500-3000 A.

The following are the possible mechanism by mans of which

the HgCO could be formedi

HCO

HCO

HCO

CHjO

+ HCOOCHj — »

+ HCO —**

+ CILO — »

+ CH-0 —*-

CH 0 -* -

HgCO + OOOCH,

HgCO + CO

& fl—V/v

2 HgCO + H2

HgCO + H

(1)

(2)

(3)

(•)

(5)

Of theBe, the reactions,1, 2, 3 involve the formyl radical

and 3» 4, 5 involve the methozy radical. The role played by thesa

different mechanisms could be established by studying the spectra of

the deuterated methyl formates. Tor this purpose, the d-methyl

formate (SCOOCH-), methyl formate-d, (HCOOCD-) and per-deuteromethyl

fornate (LCOOCD_) were eynthesised in the Chemical Bogineerlng

DiriBion and the flash photolysis of these compounds are studied* In

the f*i,aen photolysis of the deutero methyl formats (isotopic

eono. 95#) only Hie spectra of the DCO radical could be ceea and ths

-89-

HOC was oosplstely abasnt. Howeror, the end produot was found to be

only HgCO*

In the flash photolysis of nethyl fornate-d th« transient

that was observed was only SCO but the stable produot «as D 00. the

flash photolysis of methyl formate-4. i s being studied. The results

obtained ao far indicate that the reactions involving the forayl

radical are not that efficient compared to those involving CH_O in

forming the HJJO.

(b) She Flash Photolysis of DP-

In order to develop a molecular spectroscopia technique for

the isotopic assay of uranium, the flash photolysis of UF,t

(obtained from the Chemical Engineering Division}and the absorption

spectrum of lOLwere studied using a path length of 30 cm. She absorp-

tion spectrum consists of two regions; one a diffuse banded spectrum

from 4100-3600 and the other a continuous spectrum below 3300 A. Both

these systems would be effective in bringing about the photodecomposi-

tion of the molecule. Studies are being carried out to determine

which of these two systems would be more efficient In bringing about

the photcdecomposition. Also, the electrical discharge excitation of

TOP, vapour was carried out using a high frequency oscillatorD

(4-12 MB), high voltage transformer (2-3 KV) and a microwave osci-

l lator (2450 MHs). The resulting emission spectra are studied and tt»

speotra are found to oonsist of the band ^sterns characteristic of

Si» thereby indicating that the fluorine that was released as a result

of the decomposition of Urfi has attacked the walls of the discharge

-90-

tuse to fora Sif •

12. Ine 2 I * - I 2TT System of IB*

(a* Krisbnamurty)

She reinvestigation of the bands involving tha transition

2 I * - X 2TT of HB* has baea undertaken. Tht 0-0 (2886.4 A) sad

1-0 12730.22 A) bauds have bsan photographed on tha 3*4 mater

Jarrel-dah Ebart grating spectrograph (30,000 l p l ) on tha f i r s t ordar

at a dispersion of 2.5 k/xm. Rotational constants B, D, H and tha2 • +spin splitting constant / have been evaluated for tha £ s tats .

The B and P branch lines involving higher N values hare baea reassign

ned* The ezrtra lines arising out of the severe perturbation of tha

2 4 -

TJ ground utate by the £ state were studied in detail. Since tha

accuraoy of the measured values of the individual rotational lines of

the By Q and P branches is poor at this dispersion, efforts are being

Bade to photograph these bands under high dispersion*

13. Investigations on the Vacuum Ultraviolet bands of SeO

(L.C. Chandola)

Tha far end vacuum ultraviolet spectrum of SeO, lying In tha

wavelength region 1800 - 2400 A, has been photographed by passing a

trace of oxygen over Se, in a r.f discharge. Tour band systeas hare

been identified in this region and assigned to C-X, D-x, S-X sad f-x

systems^ K These bands have now been photographed en a 3-metre vac-

uum grating spaotrograph at a dispersion of 5 A/an* Because of batter

-91-

diapereion uaad by us, i t waa poeaibla to loeata two naw tenda at0 o

1936 A and 1979 A* Bfforta ara In progress to identify tha emitter

of thesa bands*

The SaO bands bara alao been obtained in sealed tubea, usingthe aeparated isotope Se and natural 8a. Work ia In progress to

ephotograph SaO bands in 1he region 2200-2400 A at a higher diaperaion

using these tubea*

(1) P.B.V. Haranath, J. Kol. Spectroaeopy, J2, 168 (1964)

14» Sanitation of Yttriaa ggdrids Bands

(S.V. Orampurohit)

An attempt was made to excite the moleoular spectrum of

the radical yttrium hydride* Three methods of excitation were tried

Tic* hollow-cathode* eleotrodeless-sealed tubea and vacuum arc* It

ma obaerr«d that -the vacuum aro suitably excited the apeotra.

Yttrium metal chipa were fixed on to oopper electrodea and mounted In

a closed chamber* This i s evacuated and waa flushed with argon aloeg

with a traoe of hydrogen* The aro waa water cooled* She apeotsale

region from 2300 to 8000 A waa scanned. Three bands with open etra-

oture wera obaerred at 5100 A, 6966 A and 7100 A. bigh resolution

apeotra. of these bands ara recorded. The band at 6966 A i s analysed

*• 1 1 - 1 1 band. The analyaia of the band at 5100 A i s being

carried out*

-92-

15» Eaoitatlfn of Yttrl"m

(S.?. Oxampurohlt)

81aee the argon used In the ezoltation of yttrium hydride

experiment contained alight oxygen, l i e uaual yttrium oxide bands are

recorded* Besides theae, a new band system la found at 3000 A. An

attempt la being » d e to record thia ayatea in Mgh resolution.

16* Excitation of CuO Banda

(S.V. Grampurohlt)

During the course of the excitation of yttrium oxide panda

It waa found a number of banda were recorded whenever the are wae

atruck between eopper electrodes. These new banda appear to belong to

the molecule CuO. Two of -fee prominent banda cone at 3200 and 3260 A.

High resolution platea are being taken to carry out rotational analyeie

of these bands*

17* Emission Spectrum of PO Ifolacule

; (M.N. DixLt and A.S. Bao)

The band spectrum of PO molecule baa been recorded In the

region 2300 A - 1300 A* There are certain unreported features which are

under inreatlgaticn. Perturbations are observed in the i bands belong-

ing to higher vibrations! l sre l s and a study i s undertaken to understand

thssn.

The isotojdc shift studies of the bands belonging to C-I,

»*-X and B-x systems by employing 1 80 i s undor progress.

-93-

18. Bho Sfady of the H>* Molecule

(ll.A. ?aset H.I. Bixit and H.A. Haxaalsfaaa)

'Jhe speotrua of ED molecule In the region 3200-5000 A has

beta «xelt«d In an eleotrodeless discharge. She fine struoture stu-

dies of these bands i s undertaken. A search i s made to locate th»

other excited states of the molecule.

19. laser Spectroscopy

(H.I. Harasimham, G. Krishnauurty, M.N. Dixit and A.3. Bao)

k selective single level exaltation of molecular egrsteos,

and the study of the resonance fluorescencep which leads to the

knowledge of many moleoular properties, has been Bade possible with

the advent of lasers. Among the properties which can b« advanta-

geously studied are

(a) The ground state molecular constants

(b) Radiative l i f e times, Franck Condon factors

(o) Transition probabilities

(d) Effect of collisions! energy transfers

In view of this, an attempt i s made to make use of the existing faci-

l i t i e s and build other apparatus needed. As a first step fabrication

of some OW lasers i s undertaken and two one metre He-He gas lasers

have been nade * With the available mirrors, the output power has

been optimised to 3 •* . Various experiments are under w*y to ia-

orease the power output and the l i f e of the tubes*

-94-

20. Hew Band System of Copper Chloride Mbleoula In the Region6900 - 7500 I

(P. Meenakshi Baja Bao)

• new band system of Cud aoleoule was reoord«d In the

region 6900 - 7500 A* The vibrations! ooastante of both the state*

involved In 1fee transition were calculated* She values of the

oanstents.for Cu 01 molecule axe Vg • 13424*2 cm" f

COg- 509.18 on'1, ^eXg» i.joa"1, U)g« 412.5 em"1,C»5eXj. 1.21 om"1.

She iaotope ebifts of the band heads for the Ou ft 01 isotopes were

calculated end found to agroe well with the observed ones*

- 9 5 -

I I ( a ) . VIBRATIOHAL SPECTRA AND MQLECDIAH STROCIDBE

1. Vlbrational Spectra and Normal Co-ordinate Analyela of D1h"lo-qenated Benzenes

(N.D. Pate l , V.B. Bartha and N.A. Naraslmbaa)

The infrarea and Reman spectra of o- , a- , and P-fluoro-

chloro and fluorobromo benzenes have been studied in deta i l In our

(1 2)laboratory ' . In order to understand the vibrations! nodes of

these molecules further, vibrational spectra of the corresponding

deuterated molecules have now been studied. Infrared spectra of the

gas ohromatographically pure parent and deuterated molecules have been

obtained In the 4000-250 om" region on a P.E. 621-grating apeotrophoto-

meter. Raman spectra were obtained on a Spex-1400 double monoehroma-0 ° +

tor with 6328 A He-He and 5145 A Ar excitation l i n e s . Depolarisatlon

r a t i o s , band oontours, isotopic s h i f t s and solid and solution spectra

were used in making unambiguous assignments for a l l the fundamentals

and many combination bands* Some of the assignments made previously

were shown to be due to Impurities and- revised assignments were given*

A 33-parameter valence force f i e l d was used for normal co-ordinate ana-

l y s i s of the In-plane modes. The normal co-ordinate analysis showed

that many of the previous assignments of the ring modes \ ) . . , ^and I)** t o r disubstituted benzenes are erroneous* Revised

assignments with good correlation with 1be corresponding benzene mode*

hare been given* The correlation for some of the modes can be scan

clearly from Pig« 12 which shows the re lat ive magnitudes of the eigen

vectors for these molecules and benmene for some of the ring vibration e l

•odea*

.1 /**. .11,11.. ll.ll

0 0

0

6660

627

0

c

Ba 0

. . If If.5450 o o

521i a O o

596I

MODE 6a f6 „ | Q1 7 13

o-FBr D

l n nm - F B r C

P-FBrB

I .821

I) 0 0 D

859D o o 0 Q D 0

810

990a D o Q D a

I I D

I l i D l . I .

Bi a 0 I •

AMODE 1

0I. K35Oa o Q O l m o U

1002O a O a Q 0 0 D D 0 D

n1015 n i lI . . 0 . I I . 0 II I

19 24 1

1010t i t • i i

7 13

l!

AMODE 12* i i • i i

19 24

CHI

FIG.12 CORRELATION OF RING MODES OF DIHALOGENATED BENZENESWITH C6H6 RING MODES.

-97-

A 16-paraoeter valence force field was employed for

normal coordinate analysis of the out-of-plane modos. Unique assign-

ments have been obtained by comparison with the d.-oompounde speotra,

for many of the weak or overlapping bands assigned as fundamentals In

the B.-oompounds.

1* N.A. larasimham, and Gh. 7.S. Bamachandra Rao, J. Mol. Bpeotros-oopy 28, 44 (1968)

2. N.A. Narasimham and Ch. V.S. Bamachandra Eao, J. Hoi. Speotros-copy .20, 192 (1969)

2. Normal Co-ordinate Analysis of CP_H and CT,D Molecules

(Bosola S'Cunha)

A rigorous normal co-ordinate analysis is made for the

molecules C?_H and CP_D using ell the available vibrational data i 12

frequencies, 4 coriolls coupling constants and 3 centrifugal stretch-

ing constants* Two types of foroe fields have been obtained; a

general harmonic foroe field with, 12 parameters and a modified Urey-

Bradley force field with 9 parameters. Both the force fields aeoount

for the observed data reasonably well.

(7.B. Kartba and N.7. Thakur*)

The Infrared spectra of the anhydrous rhombohedral mre earth

formates are being investigated, since they fom a group of simplest

ran* earth complexes, and are thus well suited for the study of effects

of oovalenqy, crystal etruoture, extent of coordination etc. Th«

-98-

atudlea bare shown that the (000) M bond la oovalent in rare earth

f ornate a and that the eovalenoy increases from lanthanum to gadolinium.

She frequencies associated with the 0-H group are found to be very

sensitive to this covalent character. I t i s also seen that the various

vibrational modes are aplit into doublets in the solid state.

Detailed interpretation of the spectra and comparative studies with the

hydrated formates are being carried out.

(* Uranium Metal Plant, BABG)

4. In-plane Vibrations of 2-chloropyrimidine and 5«6-diehloropyrida-sine

(Y.A. Sarma and V.P. Bella ry)

The infrared spectra of 2-chloropyrimidine has been

recorded from 3500-400 cm" and that of 3,6-dichloropyridaaine between

3500 and 200 cm" in various phases. In order to make the assignments

for the in-plane vibrations of these molecules, i t i s fe l t necessary

to assign the fundamental frequencies of pyrimidine, pyridazine and

thsir isotopic substituents. A normal coordinate analysis has, there-

fore, been carried out to estimate the potential energy constants and

to make theoretical band assignments*

Pyrimidine and pyridazine have CLy. symmetry and the 24

normal vibrations are grouped into foui* species, 9a. + 2a. + 5b. +

8b2 for pyrimidine and 9a1 «• 4a2 + 3 ^ + 8V for pyridasine. Dtader the

selection rule of the point group 0 ^ , the a.,, b. and b_ species are

infrared active. In this study, the 17 in-plane vibrations have been

-99-

ealoul&ted. Ihe out-of-plane vibratians of 2°chloropyrinidine aai

3|6-dichloropyridazine, belonging to the b species are assigned

empirically. The observed frequencies of pyrimidine and pyridaaim*

are taken from the literature*

Drey-Bradley and valence force fields have been used to

calculate the frequencies of pyrinidine, pyrimldine-d end 2-chloro-

pyrimidine. The in i t ia l set of potential energy constants were

transferred from similar 'molecules and refined to give the best f i t

between "the observed and calculated frequencies. Simple valence fore*

field in found to be inadequate, so some bond-angle interaction

constants which are very sensitive, are introduced in the potential

energy function..

Ihe vibrations ^20a, ^ 6 a and 18b of pyrimidine are sen-

sit ive to the substitution of chlorine In the 2-position. The other

in-plane vibrations are unaffected and the modes of vibration for the

rest of the frequencies and their assignments remain the same as in

pyrimidine.

: Ihe vibrations! frequencies of pyridazine, pyridazine-d.,

pyridazine-5, 6-dg and pyridazine-3, &-d2 h a v e b e e n c a l c u l a t e d nslng

Urey-Bradley force f ie ld . The frequencies ^20^, ^15 * l^1i ^ 6 R I

V 1 3 and V 1 8 a of pyridaaine are sensitive to the substitution of

chlorine In the 3,6-position* Potential energy distributions are ob-

tained for a l l the normal modes of these molecules.

-100-

5» Vibrational Analysis of Methylamlne and its Isotopic Derivatives

(G.S. Ghodgaonkar)

In order to evaluate the rate constants for isotoplc

exchange reactions between aethylamine and its deuterated derivatives

it is necessary to know the fundamental vlbrational frequencies of

OU_NHD. i. normal coordinate analysis of the 6 molecules - CELHH-j

CH_HD2, CD_ND2, CH_NHD and CD-NHD was therefore carried out using a

modified valence force field. Calculations were done, both with the

symmetry axis of the methyl group assumed to be along the C-N bond,

and with the actual structure where the symmetry axis of the methyl

group makes an angle 3°50* with the CN bond. The two sets of values

did not show much difference. Further work on the complete assignments

of all the isotopic molecules is in progress.

6« Vibrations! Spectra of Isotopic Borazineg

(G.S. Ghodgaonkar and V.B. Kartha)

Borazine, or 'inorganic benzene1 is the parent compound for

a large number of substituted ring compounds of boron and as such a

complete understanding of its spectra is very useful. Though considera-

ble work has been done recently^1' |3' on the vibrations! spectra of

borazine | the assignments are not oonfirmed. Moreover, recent electron

diffraction studies have Indicated that the molecule may have a Q9 non-

planar structure instead of toe planar D_ configuration assumed so Ar.

A detailed Investigation of -the vibrational speetra of this molacul«

is being carried out.

-101-

fformal coordinate analysis"' have been carried out for

this molecule only with the iTully deuterated isotopic tpecies, and

then alBO with a force field which included redundant constantB. In

view of this, the spectra of partially deuterated borazinea hare

been studied and normal coordinate analysis with these species end

with removal of redundant constants is being carried out now.

1* V.B. Kartha, S.L.N.G. Krishnamachari and C.R, Subzaaaniea, J.Mol. Spectroecopy, 2£, 149 (1967)

2* V.B. Kartha and Sf.A. Narasioham, Invited Talks, InternationalConference on Speetroscopy, Bombay, January 1967*

3* K. Niedenzer, W. Sawodny, H. Watenabe, J.W. Dawson, I. lotaniend V* Weber, Inorg, Chen., 6,, 1451; (1967)

4* Kenneth E. Slick, John W. Dawson and Kurt Hiedenzu, Inorg*Chenu, £, 1416 (1970)

7. Infrared Spectra and Molecular Motion of Water In Alkali12-Molybdophosphates

(V.B. Kartha and S. Dutta Roy*)

She alkali 12-molybdophosphates belong to the cubic systea

4and are supposed to have 0. symmetry, with 4 molecules of water per

unit cell. Recent investigation by one of us (SDH) have shown that

there are 8 water molecules per unit cell end that the structure is

better represented by !?• She water molecules held in the anion

cavities should be disordered. We have studied the infrared spectra

of these alkali 12-molybdopho8phates to get information on the Igrpe

of banding, degree of rotational fteedom and motion of water moleoulw

in these systems* Preliminary investigations have shown that there

-102-

are no liberational modes of the water molecules, indicating that

there la considerable free rotation. This ie Bupported by temperature

effect studies on the HgO bending mode ae well as HMR experiments,

further work is in progress to find the real nature of rotation and

diffusion motion* Also a complete assignment of the internal modes

of the molybdophoephate group is in progress*

•Analytical Chemistry Division, B&BC

8. yibrational Spectra and Normal Co-ordinate Analysis of Benzo-trifluoride

(Bomola L'Cunha)

She infrared spectra of gas chromatographically pure

CgHLCP- and CgD5CF_ have been obtained in the range 4000-200 cm" , on

a F.E. - 621 infrared spectrometer. Raman spectra of the two liquids

also have been obtained tilth a Spex-1400 double monochromator. Assign-

ment of -the fundamental vibrational modes i s being completed for these

two molecules. A normal co-ordinate analysis with force constants

transferred from CP H ' i s also being carried out.

1. Bomola D'Ounha, J. Mol. Spectroecopy, £5, 282 (1972)

9. Vibrational Spectra of Trifluoromethyl Derivatives of Seleniumend EhosphoroasteJ

(P.K, Wahi and H.J.

The gas phase infrared and liquid phase Raman spectra of

compounded CF^eX ( X » d , Br, CH, <My CP3 and GPjSe), ( C F ^ P,

-103-

PP and OP-EP- were recorded on Perkin-Elmer infrared 8pectrophotoai9tera

sodela 457 end 225 In the range 4000-200 cnT' and CQEERG PHO

instrument in the range 1350-50 cm** . The Raman spectra were excited

by the appropriate lines of a tunable Argon-Krypton ion gas laser of

Coherent Radiation Laboratories (Model 52). The Tibrational spectra

of all "these compounda hare been analysed and all assignmentBf ezoept

the toraional modes made. The assignments are baeed upon a study of

(i) Raman depolarisatian ratios (ii) Analogy with similar compounds

and (iil) Gas-phase infrared band contours. The PR separation for gas-

phase infrared bands have been calculated using the recently reported

formulae cf Seth-Paul et al* . The calculated PR separations are in

good agreement with the experimental value a. The PR separations hare

also helped in making poaaible many new assignments. The study has

established following Important results!

(i) As usual the C-F stretching modes have been found to

give very strong bands in the infrared, while in the Raman they give

weak and broad bands* For selenium compounds, the symmetric C-F stret-

ching mode always lies below the asymmetric stretching mode, while

reverse has been found to be the case with phosphorus compounds. For

Belenium compounds containing a single CF, group, the symmetric 0-P at

tch in general shows a perturbed PQR structure and a alight splitting

has been observed between a1 and a" components of the otherwise degene-

rate asymmetric C-F stretching mode*

ii) The CF_ symmetric deformation mode ia a good group wave-

number ft"* is always found around 745 cm and remains constant to

- 1 0 4 -

Hh 6 cm* for both phosphorus and selenium compounds. Except for

CT-PFj, and P(OF_)_, the modes always show a PQR structure. For com-

pounds! containing two or more CF, groups, the out-of-phase CF_

deformation mode i s strong In the infrared and weak in Hie Earoan, while

reverse is the case for the in-phase mode. Only a negligible splitting

la observed between these in and out-of-phase modes. The asymmetric

CF_ deformations are confined in the region 530-575 cm** .

i l l ) She (F-)C-Se stretching modes in general give medium

to strong intensity infrared bandB. The bands show FQR structure only

for CF,SeCN and CF SeOEL. The corresponding Raman band i s always

strong. These vibrational modes are found In the region 315-350 cm" •

P-Q stretching modes also behave as good group wavenumbers and are

-t -1found around 460 cm and remain constant to within ± 3 cm « This mode

shows a POP. structure only in case of OF P3? • No splitting has been

observed between the symmetric and aeymmetrio P-0 stretching modes In

(CF_)2 PP. The P-F stretching modes are confined within 10 em said

occur as very strong bands in the infrared, while in the Raman they give

bands of medium Intensity. In the case of CF_PF- a little splitting

Is observed between the symmetric and asymmetric P-F stretching modes.

The splitting is consistent with tne available data on compounds C1PF-

and BrPF£

iv) The CF- rocking modes, (which are degenerate in CFJBr

end CFjCl) show the greatest splitting. For the selenium and phosphorus

compounds these modes are found between 250-300 cm and 100-250 cm"*1

respectively. In case of phosphorus compounds, the CF_ rocking modes

- 1 0 5 -

have been found to occur below the PC skeletal bending modes as Is

the case with many other trlfluoromethyl phosphorus compounds. This

i s in contrast to the assignments of Burger et al^*' for P (CF_),«

1. W.A. Seth-paul, J. Mol. Structure, 2* *°3 (1969)

2. A* Muller, 0. Glemaer and E. Nicke, Z. Batim: orach = f B«21t732 (1966)

3. H. Burger, J. Cicb.cn, J. Grobe and P. Mofler, Speetrochim.Acta, 28A. 1275 (1972)

10. The Vibratlonal Spectra of 5-Methyl Pyrimidine and 4-MethylPyrlmidine

(V.A. Job end S.B. Kartha)

The infrared spectrum of 5-methyl PyrlMdlne vapour was

recorded In She region 4000-250 cm" on a Perkin-Elmer nodel 621 infra-

red spectrophotometer. The Raman spectrum of the liquid was recorded

with a Gary model 81 Bpectxophotometer employing He-He laser for exel=

tation. The infrared spectrum of 4-methyl pyrimidine vapour was recor-

ded on a Perkin-Elmer model 21 spectrophotometer-

If we assume C- symmetry for 5-Bethyl pyrimidine, the 25

normal vibrations of the CMJH5-C fragment can be divided into 9a^f 2»2,

5b and 8b modes. The a , b,. and bg modes wil l give rise to type A,

type C and type B bands in the infrared spectrum. The analysis of the

Infrared and Eaman spectra were made by comparison with tiie parent

molecule, pyrimidine and substituted benzenes. The characteristic con-

tours of the A, B and C type bands were used to identify the species.

-106-

The following assignments were given.

a. species

3019 (" 206

1113 (^a]

a2 species

863 ( 17a]

b1 species

880 (^5),

bp species

0> 3030 (

I, 1042 (V

>, 408 pJ'

810 ( 1ii

V2), 1570

^J, 816 (

), 725 (

? 1415 (*>19a), 1240

3060 (V7b), 1605 (^8b), 1485 (^19b), 1340 (*>14), 1193

1170 (^15), 630 (^6b), 286 (V» 18b).

-CH_ modes

2940, 2915, 2880

1440, 1380

983 (V-CH3)«1

The frequencies 1240, 286 and 226 cm represent the C-CH,«f

stretching, in-plane bending and out-of-plane bending modes respectively*

The mode V 6a was not observed in the infrared spectrum. However, th«

Raman line observed at 559 cm" and the vH progression of 557 em

observed in the electronic absorption spectrum leave no doubt about the

correctness of the assignment* Similarly a vrt progression of 816 cm

is observed in the electronic speetrum* The band at 810 om"1 in the

infrared speotrum, however, 1 P C-type. I t Is assumed that the expe~

cted 'type A band is overlapped by the type 0 band.

-107-

Ihe normal vibrations of the 0 HgH-C fragment In 4-methyl

pyrlmidlne can be classified ae 17a1 and 7an specieB. All the funda-

mentals could not be identified from the Infrared spectrum. The

assignments made are given belowt

a1 epeciea

3060 (^2Oa), 3075 (^7b) , 3045 ( ^ 2 ) , 1593 (^Sb), 1562 (^8a) ,

1476 (^19b), 1391 (^19a), 1503 (^13) , 1164 (^9a), 1046 (^ 1),

822 (^12) , 677 (^6b), 537 (^6a) , 363

aw species

826 (^11) , 746 ( ^ 4 ) , 488

modes

2941 (^CHj), 1449 (6-CHj), 989

-103-

III. OPTICS

In the Optics Section, a large number of optical components such

as flats, prisms, mirrors and some optical instruments hare been fabrica-

ted for divisional use as well as for other divisions of BAJRC and outside

agencies* Different types of Interferometers have been assigned and

fabricated for testing of optical surfaces, e.g., Twyman-Green inter-

ferometer for testing of solid l&Ber rods and other optical materials

for parallelism and homogeneity and a modified Jamin interferometer for

the analysis of deuterium content in heavy water.

In the field of thin film optics, some preliminary theoretical

and experimental work has been undertaken for the fabrication at thin

film multilayer devices. Multilayer devices are very useful in many

applications such as, narrow band Interference filters, band rejection

filters, high reflectance-no loss laser mirrors, anti-reflection coatiage

etc. For such type of work vacuum evaporation equipments and other

associated instruments are being designed and eet up in the division.

Grating replication techniques are developed and these are used for

making small size gratings for use in spectrophotaneters. An account of

the work done in these fields is given in this section.

• - 1 0 8 -

I I I . QKEEO3

Dr. M.V.R.K. Itirty SF

A.L. HaraainhamDr. K.V.S.R. ApparaoR.F. ShuklaN.C. DasT.K« Kunclur

3D2SD2SC2SC2

8A(B)

-110-

1, Compensation for Coma and Anamorpbic Effect in DoubleMonochromators

(M.V.B.K. Murty)

I t i s known that monochromators of the Czerny-Turner type

suffer from a email amount of coma due to the inequality of the

widths (anamorpfaio effect) of the incident and diffracted beams on

the diffraction grating^1"5 .

Recently, two identical monochroinators of Caerny-Turner

type were coupled together to act as a double monochromator especia-

l l y for work in laser Hainan spectroscopy. The coupling of the mono-

chromators can be favourable or unfavourable la respect to coma and

enamorphic effect. In fact , two identical conventional Czerny-Turner

monochromato^e may be coupled in four different ways in the manner

(A)enema in P i g . 13. From simple considerations x ' involving the r e l a t i o n

between angles of Incidence and d i f f rac t ion a s w e l l as d i r e c t i o n s

of coma f l a r e and dispers ion the propert ies of the four p o s s i b l e

combinations have been derived* These are summarised i n the Table

belowi

Table 1. Propert ies of Four Poss ib l e Double MonochromatorArrangements that can be obtained by CouplingTwo Conventional Czemy-Turner Mbnochromators.

Double monochromator Anataorphic Coma Dispersionscheme according to effect

Pig. 13 (a) Compensated Doubled Doubled

Pig. 13 (b) Compensated Compensated Zero

**«• 13 (c) Increase?* Doubled Doubled

Pig* 15 (d) Increased Compensated Zero

(a) (b)

(0 (d)

FIG. 13. COUPLING SCHEMES FOR TWO IDENTICAL CZERNY-TURNER MONOCHROMATOR

Xhus we may conclude that if double dispersion is required

ecu cannot be cancelled out while for zero dispersion, the com is

oanoelled out. If anamorphic effect is to be cancelled out, the moat

suitable arrangements are those shown in Figs* 13(a) and (b) or their

equivalent. It nay be seen f rom the above analysis that arrangements

of Spex is equivalent to the one shown In Pis* 13(e), and conse-

quently it has double dispersion but its coma 1A not corrected, and

also its anamorphic effect is increased. The arrangement of

Mandelberg* ' may be seen to be equivalent to the one shown In Fig* 13

(b), and consequently it has aero dispersion but its coma is corrected,

and the anamorphio effect is also compensated. If double dispersion

si cog «dth cancellation of coma is the requirement, each monochromator

of the double monochromator has to be made coma-free by using the

method of F&stie^1' or Leo*2'.

Heferences

1. ff.O. Paetie, U.S. Patent 3,011,391 dated 5 December 1961

2. W. Leo, Z» Angew. Ihys* 8, 196 (1956)

3. A.B. Shafer, L.R. Megill, and 1. Droppleman, J. Opt* Soc. Aau54, 879 (1964)

4. M.V.H.K. Murty, Appl. Opt. 11(7), 1637 (1972)

5* 03te Spex Speaker 12, So.4 (December 1967)

6. H.I. Handelberg, Appl. Opt. 9, 674 (1966)

£• Cona-Bree Double Monochromator Without Intermediate Slit

(M.V.B.K.

- 1 1 3 -

aberration coma «apecially at laager wavelengths o Some earlier

workers hare suggested some simple means of correcting thia aberra-

tion at a epecifio wavelength within the range of use of the Instruacit.

Such an instrument will have zer: coma at, say, 5000 A. and slightly

reduced coma at the shortest and longest wavelengths. Recently^ we

have proposed a modified Czemy-Turner monochromator in **,ich the coma

i s eliminated at every wavelength setting of the instrument, and, in

addition} which has the desirable properties of double dispersion and

scattered light of a double mcoochromator.

1. M.V.R.K. Murty, App. Opt. 11 (io) 2286 (1972).

3. Use of Vacuum Evaporation Methods for Production of DiffractionGratings

(M.V.R.K. Uurty end T.K. Kunchur)

There are several methods of making replicas of a surface

having fine structural features. One method is to pour a solution of

celluloid on the surface and allow the -tolvent to evaporate leaving a

thin layer of the celluloid. This layer is either peeled off or more

easily floated on the surface of water by immersing in a trough of dis-

tilled water. This method is satisfactory if certain amount of

deformation is tolerable. In the case of replication of diffraction

gratings distortion cannot be tolerated. To avoid the handling of the

delicate thin layer of celluloid, white and Eraser^ ' invented a aethod'4

involving the use of vacuum evaporation techniques.

-114-

Hecently, we have employed similar mathods for production

of reflection replica gratings. As a preliminary, trials mere aede

to replicate the fine oircular grooves made on brana and etaloleM

steel surfaces on a lathe* For parting material* we have used the

diffusion pump oil having low vapour pressure. The metal blank is kept

in the vacuum chamber* At a pressure of about 5 x 10 to 10 tm of

Hg, the diffusion pump oil is heated to deposit a very thin layer on

the metal surface. Then a layer of aluminium is evaporated onto the

same surf&oe* The metal disc is taken rat and is kept horizontal with

the grooved surface uppermost. The poly&erizable resin used by ue it

"Araldite" marketed by CIBA Ltd.* in India. It comes in two separate

containers end the reBin and the hardner must be mixed just before use*

To reduce the viscosity of the combination one should add also a

diluent* This mixture is poured on the aluminised metal master and a

glass blank of same diameter is placed on top of it* The combination It

kept in an oven for about 46 hours at a temperature of 40°C. At the

end of this period* the resin hardens and the glass blank can be

separated from the master.

After having obtained enough confidence • wa have replicated

a diffraction grating of about 25 mm x 35 mm. The first results are

very encouraging* Some of these gratings are now being used In spectre**

photometers with encouraging results* Work on the replication techni-

ques is being continued along the above lines.

i) J.0. White and W*A. Freser, Method of Making Optical Elements,O.S. Patent 2,464,736 dated Iferch 15, 1949.

- 1 1 5 -

•• Holographlcally Produced Grating In Rowland Circle and Seya-HamLokaHyps of Moup*iT'fl

(M.V.H.K. Murty sad B.C. Das)

In the present paper we have evaluated the aberration

properties of a holographically produced concave grating for two types

of recording geometry* namely (i) the constructing sources are situated

on the Rowland Circle; (ii) they are situated on lae source and the

image points of Seya-JTamioka type of mounting. It has been found that

under Rowland Circle condition tangential foci of all wavelengths are

situated on the Rowland Circle and aberrations are very small for long

range of wavelengths when one of the recording sources is situated on

the centre d' the concave surface while the other 1B situated very near

to it* It hue also been found that the holographic grating recorded

in the Seya-Nanioka type of mounting shows very little amount of

aberration compared to the conventional ruled grating*

5« Theory of an Anastlgmatic Manochromator for Vacuum UltravioletRegion

(M.V.H.Z. Murty and B.C. Das)

It is proposed In the present paper to use a concave grating

along with a concave mirror to obtain a monochrooator In which there is

no beam displacement and astigaatism is very small, fo change the wave-

length the concave grating is rotated about an axis passing through

itself. Xhe angle between the Incident and diffracted beam is kept snail

so 1faat the astigmatism is also very sitoU. An analysis of tha focussing

-116- ' •

properties of such a manoehromator ie made and it is shown that ^

be profitably used in the region 500 A to 4000 A. The addition 0? an

extra reflection may not be in itself a disadvantage in Tie* of the

fact that reflection properties of coatings are being constantly

improved.

6. A Modified Jamin Interferometer

(M.V.R.K. Murty and R>F* Shukla)

The conventional Jamin interferometer suffers from the die*

advantage that fringes are set against a fixed reference nark such aa

a crosswire. There may be fringe shift due to the variation of

temperature end pressure which causes the inaccuracies In the measure*

men*.

Guest and EU&iansA ' described a method of producing fiduciary

fringes in the Jamin Interferometer to improve the setting accuracy*

But they have not given any observations regarding the practical use of

the interferometer. A novel method of producing the fiduciary syatea

of the fringes in the Jamin interferometer is presented. Xhe application

of the Interferometer in the heavy water analysis is also discussed*

1) P.G. Guest and Wendell M. Simmons, J. Opt. Soc.Anu, £J, 319 (1953)

Analysis of DgO

The schematic diagram of the intarferometer is shown 1 B

Pig.H. Fig. 15 snows the *hite light fringes. Xhe Interferometer can b*

used for the measurement of difference In indices of refraction of two

IDENTICAL GLASSPLANE WEDGE SHAPED

PLATES (1&Z)

STANDARDLIQUID iCOLLIMATING

PLAN OF OPTICAL PATH OF BEAM

UPPER BEAM

LOWER BEAM

ELEVATION OF OPTICAL PATH OF BEAM

FIG. 14 SCHEMATIC DIAGRAM OF MODIFIED JAMIN INTERFEROMETER.

-118-

liqulda having very nearly tiie Bane composition* Shis hat been uaed

in standardising a atthod for analysis of 1 ,0 In DgOa Liquid ce l l

having two chambers, one la the path of eaoh of the beams* Is f i l l ed

with standard heavy water and sample. She beams of light below the

liquid meniscus pass through thea and above the liquid surface

traverse completely In air forming a system of interference fringes*

Thle upper set of fringes i s fixed In position and acts as a fiduciary

system. The upper and lower bands are separated by a sharp dark l ine .

The width of this line i s made snail by means of a parallel plate of

suitable thickness at 45° In the path of the beams* She lower set of

fringes i s shifted relative to the upper set because of difference In

indices of refraction of pure heavy water and sample* This fringe

shift Is measured by bringing the central bright fringe of the lower

system and fiduciary system Into coincidence by means of compensator*

The compensator consists of two wedges In opposite directions* Move-

ment of one wedge relative to the other by means of a micrometer head

Introduces path difference which can be reed In terns of drum scale

divisions*

Calibration

She standard concentrations of heavy water are prepared by

quantitative dilution of the pure heavy water. The Instrument la then

calibrated for standard concentrations of heavy water against the fringe

shift in terms of dim scale divisions. Hg.16 shows the calibration

curve for heavy water analysis. The setting accuracy of the instrument

has been found to be better than A/GO, The precision of measurement

(a) (b)FIG.15. WHITE LIGHT FRINGES OBTAINED WITH

THE MODFIED JAMIN INTERFEROMETER.

- 1 1 9 -

800r

600

400

z

200

TEMP. = 25#CHUMIDITY = 15%

CELL LENGTH = 25.37mm

(3:2 04 0.6% H2O

0.8

RG. 16. H2O IN D2O CALIBRATION CURVE OBTAINED WfTH MODFIEDJAMIN INTERFEROMETER.

-120-

in 25*37 an cell is 0«01 per cent in the range of Interest 99# and

above. Hg.17 shows a photograph of the complete interferometer

which has been used for the above work.

7. Some, Considerations of fjgeau Interferometer

(M.7.R.K. Murty and S.P. Shulds)

The Piaeau lnterferometsr is en Instrument mainly used for

the precise measurement of flatness and sometimes the homogeneity of

flat optical components. Several authorsN • ' considered modifloeitlon

of the Pisoau interferometer in devising complex colllmating lens

systems to correct spherical aberration and reduce the fooal length

to as small e value as possible* The arrangement of source of light,

lens system t:rtc. is shorn in Fig. 18. There is a type of Fiseau

interferometer devised by Kilgere where a concave mirror is uaed off

axis and the theory of aberrations of this, in so far as their rela-

tion to Hie function of the instrument, is discussed here.

Angular Aberrations cf a Concave Mirror used Qff-axiB

The actual arrangement of Fizeau interferometer is shown in

M g . 19. The radius of curvature of the mirror is 2700 mm and its

dear aperture 200 mm* The point source is displaced by 150 mm from

the middle ray of the collimated beam. The «n*nrl'"mti value of angular

aberration for no longitudinal fooal Bhift has been calculated to be

622 z 10 radians. This can be further reduced by choosing the valut

of longitudinal shift to (|~) where 'H«; is ths shift of the point

source from the axis and r is the radius of curvature. Then the angu-

FIG. 17 MOOJFIEO JAMIN INTERFEROMETER

- 1 2 1 -

O SOURCE—A— PIN HOLE

^ E Y EBfeAM DIVIDER

FIG. 18. SCHEMATIC DIAGRAM OF SOURCE AND LENSSYSTEM OF FIZEAU INTERFEROMETER.

-1 ?? -

FIAT UNDER TEST

MASTER FLAT

POSITION

O SOURCE

—CONCAVE MIRROR

FIG. 19. FIZEAU INTERFEROMETER WITH OFF-AXIS CONCAVE MIRROR

-123-

lar aberration beeoaea 279 x 10 radlana. Assuming an air gap of

5 •» and uaing «a 5461 A, m hara a maximum arror of 7 x 10~*ft2

(t - £ • where 9 la the angular aberration, t air gap between taat

Plata and optical f lat , wavelength of l ight) 1B the order of ln-

tarferanoa for optimum choioe of tha value of longitudinal focal ahlft.

Hence the result ahows -that tha above eyatea can be used with confi-

denoe for high accuracy meaaurementa In apite of tha airror being

used off cods.

Alternate arrangement

An alternate arrangement aimilar to Hilgers la ahown In

Fig* 20 In which a lene i s used for collloatlon. Pocal length of the

lena la 2400 mm and the mail mum angular aberration for Hie lena la

calculated to be 82 z 10 radiane. The IBWT1""1" arror In tha order of

interference la 6 z 10 under the oondltiona of t • 5 as and

A • 546I A. Thua we aee here alao the arror ia so emsll that i t ia

not significant.

Heferencaa

1. W.O.A. Taylor, J. Soi. Inatrum. 2k, 399 (1957)

2. P«B. Yoder, W,W. HoUie, J, Opt* Soc. Am. £L» 858 (1957)

3. V. Tnyman, Priam and teno Making, published by Hilgera andWatta Ltd, London p.384 (1957)

8. fabrication of 19" Yaeuun Coating Plant

(X.Y.S.B. Apparao)

Fabry-Perot intarfaromater platee, band paea f i l tera , narrow

band Interference f i l tera, laaer mirrora and such HUa film optioal

darleaa are In conatant uee In the SlTieion. Btaaa filtera are made by

-124-

FLAT UNDER TEST

EYE POSmoN

BEAM DIVIDEROSOURCE

PLANE MIRROR

FIG. 20. FIZEAU INTERFEROMETER WITH COLUMATIN0 LENS

-125-

depositlng In vacuum a number of thin films of different dielectric

naterlals of specified thickness one over the other on a suitable sub-

strate plat Co In Hie fabrication of such filters the most isportant

factors to be controlled are, first the uniformity of leyer thickness

orer the area of the substrate, and secondly controlling the overall

thickness of each layer. lack of uniformity causes a shift of chara-

cteristic wavelength orer the surface of the filter while errors in

overall thickness of each leyer causes a drop In overall performances*

Ene first requirement, vis, layer uniformity, eaa be

attained by rotating the substrate in an evaporating vacuup chamber

having a nritritmim diameter of 19" and about 20" In height, and by plac-

ing the source off-axLally at a specified point. The second requirsnat

is the thickness of each layer of specified material can be controlled

by monitoring the thickness during evaporation using a good optical

monitor*

fo fabricate different high precision optical filters, a 19"

vaouuB coating unit with th* above facilities Is designed sad i s being

fabricated In the Division.

9; A Hew Method of *PMn.im» TMrVweaa Monitoring

(K.T.S.H. Apparao)

In thin fllB optics, film thickness Is a very important pars-

Mter for basic Investigation as well as for f11B applications. Alaost

all optical applications of thin films require coatings of well-defined

and precisely controlled thickness. lumber of oethode are known for

-126-

monitorlng ttie thickness of thin films during deposition. But tho

accuracy of most of these methods is not sufficient In the fabrication

of Interference filters and other precision coatings. For such devices

the error In film thickness should be less than about 2 & A new

optical monitor ie designed to achieve this precision and is being

fabricated.

Ibis method consists in measuring the transmittanee of the

monitor plate at two wavelengths and finding the difference. A mono-

chromator is used which contains a chopping system which switches the

measurement between the two wavelengths* The chopping takes place at

the optimum frequency of the detector and the measurement of the

difference in transmlttance is the amplitude of the a*c« signal from

the detector. The two wavelengths, one polarised perpendicular to th«

other, are obtained using split polariser and the chopper consists of

another rotating polariser. The signal from the detector was first

amplified and tben synchronously rectified to give a d.c. output and

the output is read on a current meter. The design is such that the

output of the detector reads zero when the thickness of the film Is

quarter wavelength at which point the deposition Is terminated.

10. Thin-Film Flicker Refractometer

(K.V.S.R. Apparao)

To measure refractive Index of dielectric thin films a hew

inatrunant called "Thin Film Flicker Refractometer" is designed and ft

working, model, of Hie same was assembled and tested. The principle

-127-

involved In the design of the instrument is due to AbleB1 and makes

use of the fact that for light polarised with the electric vector in

the plane of Incidence, the reflectance of a film of refractive Index

n. on a substrate of index n at the angle defined by tan © • n /n la

the same as that of uncoated substrate* The method involves the adjust-

ment of the angle of incidence until the intensity reflected by tiie film

is the same as that of the substrate • To judge this intensity matching

a photometric principle is also made use of in the design of the refra-

ct omster. According to this principle» when two identical patches of

light fall on a screen in the field of view alternately at a frequency

of about 18 c«p,s. the human eye detects flicker of the light if the

two patches ere of different intensity and the flicker disappears when

the intensity of the two sources are identical.

The main part of the instrument 1 B a prism spectrometer

wherein the telescope is replaced by a "Flicker chamber" which is moun-

ted on the telescope arm* The "Slicker chamber" consists of two iden-

tical slits of about 5 am x 20 mm size each arranged in front of the

chamber! a fixed mirror and a rotating sector mirror placed in the

chamber in such way as to interrupt one beam of light and reflect the

other beam into tae field «ff riew alternately at a frequency of about

18 o.p.e.

She sample fila coated partly on a substrate is mounted on

the prism table and the collioated polarised monochromatic light fros

the colllaator falls on the film as well as on the substrate symmetri-

cally and get reflected end respectively #attr the two slits of the

-128-

"flicker chamber" • The turn table alongwith the "flicker chamber*

is rotated until the flicker in the field of view disappears and the

angle of incidence at the film is noted. The refractive Index is

then computed from the relation given above*

This instrument can tie used to measure the refractive Index

of any dielectric material in the farm of film and the accuracy of

the method is about + 0.2$.

11. Thin-Film Calculations Using Computer

(K.V.S.R. Apparao)

In view of the ever-increasing use of multilayer thin film

coatings in the field of optics and spectroscopy* it is Important that

rapid and accurate method of calculating reflectance* transmittence of

such coatings be made available. Precise calculations of reflectance

and transmittance are necessary both to aid the designer in his com-

plex problems and in general to provide a basis for comparing the

theoretical and experimental results. This film calculations are in

general exceedingly complex because of the involved mathematical steps

and one has to do such calculations on high speed electronic computers.

A programme was developed using CDC-36OO for calculations

of reflectance, transmittance and the phase angle an reflection of non-

absorbing filters of upte 50 film stack, for any number of wavelengths

and far any angle of Incidence. The programme also calculated deriva-

tives of reflectance with respect to the thickness of each layer for

each wavelength. Sheee derivatives indicate the thickness sensitivity

-129-

of each layer with respect to the overall performance of the f i l ter

and these values are very useful in The actual fabrication of any

dielectric multilayer f i l t e r . These calculations are performed in a

single run with one set of input data, namely number of films,

refractive Indices, thickness, range of wavelength and the angle of

incidence to be covered*

Using this programme, results for a number of different

types of f i l t er designs are obtained.

12. Thin-Film Filter Design Using Computer

(K.V.S.R. Apparao)

The problem of designing a practically realisable multilayer

f i l t er , to meet given optical specifications i s often a difficult task

because of the complexity involved in the problem and limitations on

the choice of available materials. On the contrary, i t i s relatively

easy to modify a known design to meet the required specifications.

For such problems, a programme i s being developed using

CSC 3600 starting from a design which moderately approximates the

desired characteristic. Obis method, called "Refining method",

t s in calculating the partial derivatives of the reflectance with

respect t o the individual film thicknesses and solving for the

ness increments which provide a better f i t . These new thickness incre-

ments are incorporated in fee init ial design end the performance

of the improved design i s obtained. Th$ calculations ere repeated,r*i • ' . ' •

taking the above design as a starting point, In an iterative way until

-130-

the required characteristics are obtained..

13. 10.6 metre Ebert Grating Spectrograph

(Habavir Singhf G. Krishnamurty and M.V.B.K. IJurty)

High resolution spectrographs play an important role in

providing information to understand the structure of atoms and mole-

cules. In order to carry out the high resolution studies in the

optical region of atomic and molecular spectroscopyf the fabrication

of a 10*6 aatre Ebert grating spectrograph has been undertaken, Eie

off-plane Ebert arrangement was chosen for its economy of optloal ele-

ments used (a single large concave spherical mirror serves both as

collimating and focussing element) aad its simplicity of lay-out and

ease of operation.

The dispersing elemsnt la this spectrograph is a plane

reflection grating (Bauach and Lomb). It hat ruled area 206 x 128 ma

and the blank dimensions are 220 x 135 mm. Hue grating is ruled with

1200 groovea/mm and is biased at one micron In the first order. A

concave spherical mirror of 50 oma diameter and 10*6 mettree focal len-

gth is chosen as the collimatlng and focussing element.

The following accessories of the spectrograph have been

designed and fabricated.

l) She concave mirror mount made of aluminium for holding

the nirror has been casted. Two steel supports axe provided to support

mirror holder rigidly.

-131-

ii) The grating mount rests in a turn table which enables

the grating to turn to the required angle about the rertieal axis*

the grating mount is provided with screws to natae the necessary adjust-

ment for the grating*

ill) A steel frame for holding the plate holder has been

fabricated* She plate holder can be racked upwards and downwards by

means of a bevel gear* The plate holder has been casted and the

required curvature to obtain the spectrum in good focus has been provi-

ded In the plate holder. The camera can take three 2" z 10" plate8t

14* fabrication of a 35* Concave Grating Spectrograph

(M.N. Dixit, M.V.R.K. Warty and K.V.5.H. Apparao)

As per the programme of the Division to develop better faci-

lities in the field of high resolution studies, a 35* concave grating

epectrograph in the Eagle mount is being assembled for the Division.

All the parts of the spectrograph, like, the grating holder*,

the turn table, the plate holder, the camera assembly, the slit holding

device etc* are completely designed in the Division. The design of the

sliding mechanism of the plate holder ie unique in the sense that the

56" plate holder in the zero position can be swung out and turned so

as to unscrew the cover of the camera to load the photographic plates*

The camera can take three 18" x 2" plates and can cover about 2400 A In

the first order at a plate factor of 1.5 A/mm. The grating is biased

for 1.16 enabling the spectra to be photographed at higher orders,

at higher dispersion and resolution.

* is designed In such a way as to rotate the grating aboutall the three ax«s.

-13?-

IV. SERVICE ELECTRONICS

The service eleotronios group, in addition to doing regular

aaintenance of a l l electronic equipments in -die d iv i s ion , also

carries out fabrication of a l l electronic equipment8 required by the

various groups*

During this period, three numbers of 6 V 3 amps DC regu-

lated power supplies were fabricated and supplied against the

requests of Fuel Reprocessing Division and Atomic Minerals Div i s ion .

These power supplies have l ine regulation better than 0.02

percent for + 10$ change in input voltage and output impedance l e s s

than 0.025 ohm. The dr i f t in tiie output voltage after f i r s t hal f an

hour iB l e s s than 1 mV per hour.

A low voltage spark source for the exci tat ion of »nall area

of the order of 25 to 40 microns i s fabricated. This provides a

starting voltage of 2000 V DC and i s oapable of giving average current

upto 50 mA DC during sparking*

A tuned amplifier having a gain of 3000, tuned to a frequenoy

of 33 cycles per second using twin-T network in the feedback loop l a

fabricated. This amplifier x e j e o t s 50 cyoleB/eeo signal by a factor of

60 and 100 cyc le s / sec by a factor 500*

This amplifier i s required for the modulated baam photoneter

used for nonitoring the thiokness of thin filma vary p reo i s e ly .

During th i s period, a miorowwre oso i l l a tor and an u l t r a -

Sonic generator sent by Dr. Qoyal of Medical Division wars lervioed

-133-

to aliminata defaotire oparatioc.

Maintananoa and •ewioiog of a l l tta axiatiig aleotronio

equipment* in tha division hara alao baeii dona tfaroughoat fha jaar«

-134-

IV. SERVICE ELECTRONICS

P.K.S. Prakasa Rao SD2

H.S. Dua SIP.R. Pawar SiP.S. Hariharan SA BlCM. MuaalG 3& B)

APPENDIX I

ANALYTICAL MfcTHODS DSTELQPKD IH

SPECTROSCOPY DIVISION, B .A .R .C

SPECTROCHEMICAL METHODS

(Quantitative and Semi quantitative)

-130-

Material

1) Aluminium

Analysed for

Ag,BtCdsCo,Cr,Cu,Fe»Sa, %,Mh,Ni,Ti,VSi , Zn

Range

10 - 1000 ppm

100 - 2000 "

2) Aluminium Alloys(BARC-I-111, 1971) Ti

Fe.Si

O.OO6-O.15 i»0.011-0.06 "0.1 -0.6 "

3) Antimony

4) Antimony Oxide

ft) Arsenio, ArsenicOxide

Ag,B,Cu,Ga,Mn,Ni,Pb,SnBi,Cd,InAl.lfeAs,Fe,ZnSi

Al,B,Bi,Cu,Ga,Pb,SnCd,Fe,In,NiSiAsfZn

Cr,Hn,PbBi,Go,NiAl,Cu,%Cd,2nSi

0.525

10

25

2

51020

125

2050

- 10-100-100-500-50a

- 50-200-200-200

-100-100-100-500-500

ppm«i

H

It

•1

ppm11

11

11

n11

«

11

11

6) Arsenic Chloride*AxBenic Oxide(preconcentration)

Al,Bi,Cd,Co,Cr,Cu,Mgtl'ii,Ni,Pb,Zn

Limit depends on to ta lamount of sample taken

7) Barium Sulphate(BARC/Speo/2ij1968)

Sr 0.0005-0.5 i>

B) Bismuth(BARC-4861I970)

Ga,In,Pb,SnAl,B,Co,Ni,SbFe,GeA3,Cu,Si,Zn

125

10

- 50- 50- 50- 50

ppmti

it

11

9) Bismuth Alloys(BARC-533J1972)

PbTe

0.002=0,1 Jo0.02 -0.5 »

10) Bismuth Oxide Se 10 -250 ppm.

-139-

Material

11) Borio Aoid(AEET/Speo/I8|1966)(BAHC-56411971)

12) Boron Nitride(BARC-632|1972)

Analysed for

Al,CaflfefPbCr,Fe,Si,SbAa.P

Pb,SnBivSbAl,lfeFeAs,Ca

Range

2 - 100 pam5-200 ••

10-200 "25 - 500 "

2 - 5 0 ppm5-200 «

10 - 200 "20 - 200 "50 -1000 "

13) Cadmium Oxide,Cadmium Sulphide(BARC-5931 1972)

Bi,Cu,Nl,Pb,SnAl,Co,SbFe,lfeAa,Zn

1 - 5 0 ppm2 - 1 0 0 H

5-250 M

10 - 250 M

14) Calcium Fluoride B 0.1-2.5

15) Calcium Oxide(BARC-469J197O)

19) Copper Oxide

B,CdMhCrAlJfe.Si

Be,SnBifMn«YCo,Cr,Mo,Pb,SbAl,Aa,Fe,MgtNl,Te

0.1 - 5 ppat2 - 50 »5 - 1 0 0 ••

10 - 200 '•20-500 "

16)

17)

18)

Caloium Phosphate(Bone Aah)

Cerium Oxide(AEET/Spee/7|1964)

Cobalt Oxide(AEET/Spee/3;1964)

Cd,Cr,Eg,MAs,Zn

La,NdfSmPr

Al.CuCr,Mn,NiFe.lfe

n,Ni 2-10020-200

0.01-0.50.05-0.5

2-1005-100

25 - 250

ppmn

96n

ppmit

n

1 - 100 ppm2 - 1 0 0 M

5 - 2 0 0 M

20 - 500 "

20) Dysprosium Oxide ErGd.Ho.YTb'

0.005-0.50.01 - 10.02 - 1

21) Erbium Oxide(BARC-471|197O)

Yb

Ho

0.0025-0.1 960.005 -0.5 "0.025 -0.5 "

-140-

Material

22) Europium Oxide(BARC-53211971)

25) Gadolinium Oxide(AEE0/8peo/i4l1964)

24) Gallium Oxide(BAHC-528J1971)

25) Germanium Oxide

26) Gold

27) Bolmium Oxide(AEEl/Spec/i6}1966)

26) Indium Oxide(AEEl/Spec/2O»1968)

29) Iron Fexxio Oxide(AEE3/Spec/5f1964)

Analysed for

Od, SBTb

%, Bu, SB, Tb

CuAl, InBi, 6ef PbCr, Fe, Kg, Hi

Al,B,Be,Bi,OufCr, 1

Cr, MnAg,Co,Hi,Pb,Ft,SaBi, Ou, Fe, 8bZn

T

Er

GaHiAlPb, P tFeSb

CuA l , IfaCo, l aPb

Bang*

0.005 -O.O1 -

0.01 -

0.5 -2 -5 -

10 •

5 •

2 -5 -

1050 •

0.0050.0150.03

0.525

102050 -

25

1020

0.1 it• 0.1 •

0,5 $

• 50 pi>a• 100 •• 100 "• 200 "

» 250 ppa

- 50 ppa- 100 H

- 100 B

- 500 "

- 0.1 it- 0.5 "- 0.5 "

- 20 ppm- 20 "- 50 •- 200 "- 200 "- 500 "• 500 "

- 20 ppn- 50 "- 100. •- 200 •

-14-1-

Material Analysed for Bange

30) Lanthanum Oxide(AEET/SPeo/6t1964,BARC-472;197O andBARC-47311970)

NdPrCeAg,Be,Ge,Mn,Pb,8nfTB,CrtOCo, Ti

0.001 - 0.05 £0.002 - 0.05 "0.003 - 0.05 "

2 - 1 0 0 ppa5 - 100 w

1 0 - 1 0 0 •

31) lead Sulphate Bi , CuFe, 3b,AB, SiZn

5 - 250 ppa10 - 250 "25-250 "50 - 250 "

32) Lithium Fluoride(BARC-4961 1970)

Ca,Cr,Ott,Bu,E,Hg,Mn,Na,Ni,Fb,Ti 10 - 25O ppn

33) Hftgnesium,Oxide.

Ag,B,Be,Bi,Cd,Co,Cr,Cn,Fe,Ge,In,]in,Ni,Pb,Sb,Sn ,Ui,V.Zn

1 - 5 0 0 ppm

50 - 500 •

34) Manganese Dioxide

37) Nickel Oxide

Ag,Be,Bi,Ou,In,Pb,Sn 1 - 5 0 0 ppaAs;B,Cd,Mg,lTa,Sb 5 ~ 500 "Al,Co,Cr,Fe,Hb,Ni,a,T 1 0 - 5 0 0 w

Zn 20 - 1000 "

35)

50

Molybdenum Oxide(BABC/Spec/22»1968)

Boodymi.um Oxide

B,Co

Pr,

»Cr,e>Mg

Sm

.si ,S ii 5

25

0.05

- 100 ppa- 250 «

- 0.5 ft

Ag, Co, Ou, Hni l , Mg, HaBi,Cd,Fe,Pb,Sb,Si,SnAs,Ba,Cr,Ifo,T,Zn

1 - 2 0 ppa2 - 20 w

5 - 100 •10-100 "

Material Analysed for Sange

38) liobium Oxide Kit, Pb 5 - 500 ppn(AEBa/Anal/7»1963 & Sn 10 - 500 "BAHC-4951I97O) F«, Mo 50 - 500

at, n. 100 - 1000 "

39) Phosphorus (red) B, Bi, Cr, Mn, Sb 5 - 500 ppm11, Ou, Fe 10 - 500 n

As, Kg 25 - 500 "Ca 50 - 500 w

8i 100 - 1000 "

40) Phosphorus Chloride Ag 0.01 - 2.5(preconcentration) Au 0.O5 - 2.5

fd , fa 0 . 1 - 5 "Zn 0.5 - 5 M

41) Phosphorus Oxyohlorid© Ag 0.O1 - 2 .5Au 0.05 - 2»5 "Cd,Pb,Sn,Tt,Ti 0.1 - 5 .0 M

Zn 0.5 - 5.0 "

42) Platinum, Platinum* Ag, Ou 2 - 2 0 ppmHhodium Alloys A l ^ C e . C g ^ l f a , I „(BAHC-2O7H965) Mo,Pb,Pd,8n,V. | 1 0 Z 0 °

AufFetIn,]fi 20 - 200 n

Sb, W 100 - 500 "Bh 0.1 - 5 i»

43) Potassium Bromate Ba 10 - 10,000

44) Potassium Pluo t^ntalate(BAEC-46511970)

Pe,Cr,MnHi

Sn,Ti,Zr 5 0 -

2 5 -5 0 -100 -

1000 ppm1000 "500 «1000 M

-H3-

45)

46)

47)

48)

Material

Praseodymium Oxide

Bamarium Oxide

Scandium Oxide

Sil icon(BARC-I-63?197O)

Analysed

l a ,Ce,

Btt.

la ,

B

SmUd

« .

T

for

Hd

Bange

O.O1 -0.1 -

0.01 -

0.005 -

1 -

0.5 5*2 "

0.5 J-

0.5 i

20 ppm

49)

50)

51)

52)

Silver Chloride(BARC-484|197O)(BA.RC-539J197O

Sodium Chloride(BARC-283 |1967JBARC-284;1967)

(preooncentration)

Sulphur

Tantalum Oxide(AEEa/Anal/7,1963)(7iARC-64811972)

Bi , Ifo, XiCo., 6a, PbB,Co,Cr,%tSb,SaAl, InFe

Aut3i,Cd,Co,Cu,InfMn,Pb,Pd,Tl

All rare-eartna

Ag,Al,Ca,Cr,Cu,

Fe, TeA.

Va.Hi, Pb, TiFe, Si7Al, Ho, SJXHb, Zr

|I

1

0.10.20.5

15

- 25 PP»- 25 •"- 25 "- 25 "- 50 •

Ids i t depends on amountof sample

51025

2.55

10152540

taken.N

- 100 ppm

- 2 0 0 "- 200 "

- 1000 ppm- 1000 "- 1000 "- 500 »- 1000 "- 4000 "

53) terbium Oxide(BARC/SPec/i6|196"6)

0.01 - 0.5

- 144 -

ISr-terial

54; -aorium, Thorium Nitrate,Thorium Oxide.

Analysed for

Ag, B, Be, Cd, Gft

HaCa, K, Mo, ZnP, S i , Zr

Bang*

.11

51050

- 2 ppa

- 20 •

- 100 "- 200 •- 1000 "

55) Tin Oxide(AEEffi/Spee/1011964)

Bi,Cu,Fe,Fb,SbAs, Zn

10 - 1000 ppa100 - 1000 *

56) Tungstio Oxide(BARC-I-72|197O)

57) Uranium, Uranyl Nitrate,UO j 1LO_.

\ V n / 51 y y)

Hi. Cr,AlSi

B,Co,31.« i

Zn

Ma

Fe, Sn

Be, Cd, Ma, Ni, Sn,Cu,In,Mb,Pb,Sb

1251050

0.112520

- 20 ppn- 20 "- 50 "- 50 "- 250 "

- 5 PP«. 20 "- 50 "- 50 "- 250 "

(BARC-I-11O|1971)

(AEBT/Anal/i7|1963)

(BARC-664J1973)

Mo

Bu

Ca

Ag, MoCa

1 •

5

Limit depends onamount of sample

200

110

- 10 ppm- 100 n

totaltaken- 10,000 ppa

20 ppm- 200 "

58) SoditDB Diuranate OuBAsP

510100600

- 50 ppa- 50 »- 1000 »- 6000 n

- 1 4 5 -

59)

60)

61)

62)

63)

64)

65)

Material

Uranium Bare earths in(AEEl/Anal/23|1963)(AEE!l/Anal/24|1963}(AEE!1/Spec/I7|1966)(BAHC-I 106 |1971)

Uranium Tetrafluoride

Ttterbium Oxide(BAIlC-47111970)

Yttrium Oxide-Bare earths in -(BARC-521J1971)

Yttrium Oxide(BAEC-621|1972)

Zino Oxide, Zino Sulphidu(AEEiy'Spec/1511965)

Zirconium Oxide( A E m / A n a l / ^ ^ )

Analysed tax

Od, EaDjr, Er, Sm

B

Er, 33nLa

Tb'

MnCu, Ga, FbHi, SnB, Ca, Cr. FeAl, Mg, Sb, BICd

fi,Bi,Cr,fh,Ki,Eb,SnCd, Co, Cu, SbBi, Fe

Hf

Bange

O.O4 -0.1 -0.2 -

0.2 -

0.025 -0.035 -

20 -50 -

0.1 -

0.1 -1 -2 -

10 -50 -

2 -5 -

10 -

O.Ci -

1 pp»2 •4 *

20 ppm

o!5 "

500 ppm500 •

1 3*

100 ppa100 "100 "100 "100 •100 "

250 pp»250 "250 "

0.25 #

X-EAY FLUORESCENCE TECHNIQUES

-148-

Materlal Analysed for Range

1) Aluminium-Zirconium Alloy Zr Entire range

2)

3)

4)

5)

6)

7)

8)

9)

10)

11)

12)

13)

14)

15)

16)

Cupro-Nickel Alloy

Low Alloy Stee ls

Plain Carbon Steels

Precious Metal Alloys

Stainless Steels

Bare Earths- Mixtures andconcentrates.

Dysprosium Oxide

Gadolinium Oxide

Lanthanum Oxide

Neodymium Oxide

Praseodymium Oxide

Samarium Oxide

Yttrium Oxide

Uranium - Calcium in .

Uranium - Rare Earths

CuNi

CrMn, MoNi

Mn

Ag, Au, Cu, Pd, Pt

Cr, Mn, Mo, Ni

Individual Bare Earths

E r , Eu, Gd, Ho, Tb, Y

Ey, Eu, Nd, Sm, Tb, Y

Ce, Nd, Pr, Sm

Ce, Eu, Gd, La, Pr , Sm

Ce, La, Nd, Sm

C e , Eu, Gd, Nd, P r , Y

By, Er, Su, Gd, Ho, Tb,

Ca

All Rare Earths

8 Entire range

0.1 - 2 %0.15 - 1.5 %0.15 - 5 %

0.3 - 1.6 %

Entire range

Entire renge

Entire range

0.005 - 1 %

0.005 - 1 %

0.005 - 1 %

0.005 - 1 $

0.005 - 1 i»

0.005 - 1 $

Yb 0.005 - 1 / 6

20 - 500 ppa

20 ppa- 1.0 %

- 1 4 9 -

Material

17) Uranium

18) Thorium

19) i^ TaP7, Ta2O5

20) CaSO^

21) Niobite , Tantalite

22) Arsenic Sulphide

23) Tin Oxide

Analysed for

Br"

Cl"

ZnUZr

Pe, Vtat NbTi

Ity, Tat

Ta

AB and S

As

Bange

20 ppa - 1.0 i>

50 M - 1.0 %

20 - 500 ppa50 - 1000 "

100 - 1000 "

50 ppm - 1.0 i>20 M - 1.0 "

0.005 - 256

Entire range

Exact composi-t i o n

20 - 500 ppm

ISOTOPIC AHA1YS1S

-152-

ttiterial Analysed for Range

1) Boron Trifluoride

(AEBT/Spec/121 1964)

10B and Entire range

2)

3)

4)

5)

6)

7)

Chloroform-D

Lithium

Bitrogen

(Tranium

Water(AEET/Speo/13;

(B.A.B.C. - 281;

1964)

1967)

CHC1

*li

2 3 5u

DgO and E£0

Deuteriumconcentration

0 - 15 %

1 - 99 $

0.4 - 99 $

Natural 100 $

Entire range

Entire range

MISCELLANEOUS METHODS

(Spectrochemieal and Spectrophotometric)

-154-

Material

i ) Gases In Metals(BARC/Spec/23| 1968)IBAHG-336} 1968)(BAHC-3371 1968)

Analysed for

»2'°2

Range

10 - 500 ppa

25 - 250 "

2) Argon

CO

CO,,

5 - 100 ppm

2 - 1 0 0 H

1 - 1 0 0 "

3) Graphite(AEBT/Spee/4| 1964)

B 0.1-20 ppm

4) Graphite(BAEC-575; 1971)

Ag, VBi,Cr,CutGa,In,Al,Be,Co,Mg,NiB, Ca, StCd, FeAs, Si, Zn

0.5 - 20 ppm1 - 50 M

2 - 50 ?5 -50 M

10 - 200 "50 - 500 "

5) Heavy Water(AEET/Spee/11} 1964)

Cl

NO,

so:

0.04-4 /ml

0.01-0.5 /ml

0.01-2 /ml

30-150 /ml

6) Marine Sediments

7) Methanol

6) Minerals & Ores -

9) Minerals & Ores -

10) Minerals & Ores

All

Basalt

' Bauxite

- Chromeores

sstsllic ispuriiiss

Cu, ?e( Mg, SiCo,£fo,MoyHi,VfZn

Water

Trace impurities

Trace impuiitiea

CaCo, Hi, Vlib

ppb

10 -100 -

0*02£

5 -50 -

250 -

range

1000 ppa10000 M

and above

1000 pps1000 "

. 1000 "

Material

- 1 5 5 -

Analyatd fox Bang*

11) Minerals ft Ore* - Copper

Au, Mo, HI, Pb, 5b, TAa, Zc

0.001 o 10 ^0.001 - 0.1 %0.005 - 0.5 i

0 . 1 - 2 .5 SC

12) Minerals ft Ores -Jaduguda ores

13) Minerals ft Ores -Lithium ores

(AEET/Anal/26j 196?)

14) Minerals ft Ores -Niobium and Tantalum(AEET/Speo/8j 1964)

15) Minerals ft Ores -Tungsten ores

(BAHG-4681 1970)

16) Minerals ft Ores -Pot. Feldspar

17) Minerals ft Ores -Pyroxene

18) Noble Metals -Graphite Matrix

IS) Plent Materials

CuMoHi

Li

TiTaHb

W

Pb

Co, Cr, 5 1 , VCa

Au, G&, In , PdP t , Ru, BhBe

Ag,B,Bi,Co,Cr,Cu,Fe, {Mn,Mo,Hi,Pb,SbfSn. §7r

1005

10

0.24

0.521

6

10

0.0050-05

10 -100 -500 -

5 -100 "

- 1000 ppm- 500 »- 1000 •

- 7 5 6

-5%

-7056

- 6 5 *

- 1000 ppm

- 0.5 i>

1000 ppm1000 '10000 n

500 ppm

500 "

20) Potassium Gold Cyanide Ag,Al,Co,CutPe,Mg,Hj.,Pb,Sb.As, Ca, S i , Zn

5 - 2 5 0 ppm100 - 1000 "

-156-

Material

21) Bare Earths Concentrates(BABC-356; 1968)

22) Bare Earths Mixtures(BARC-54OJ 1971)

23) Bare Earths Mixtures(BARC-470} 1970)

Analysed for

BuY

Y

EuDy,Er,Gd,Ho,La,Sm,!Pb,Y

Range

0.1 - *g10 - T 9 J S

1 - 9C#

0.05 - 2j61 - 50#

24) Rocks and Minerals A£,B,Co,Cr,Cu,Oe,Ni,Pb,Sn 20 - 500ppaV 50 - 500 "Mo 100-500 "

25) Silicious Materials(BARC-5O4» 1970)

26) Silicious locks(BAHC/Spec/19; 1967)

27) S i l t (preeoncentration)

28) Steels - Low alloy andmild

29) Steels - low alloy(BARC/I.1O95 1971)

30) Steels - stainless

31) Water(See also Heavy Water)

Ru

Ag, MoNi, VAu, Bi, Co, PbCu, S'oPb, Zn

Sc

CPSSi

' Crfifa, HoNiSi , V

CPSSi

All metallicimpurities

0.1

5 -10 -50 -

100 -500 -

0.1 .

0.09 -0.01 •0.01 •0.05 •

0.20.150.150.1

0.090.0170.016

0.4

500 ppm1000 "1000 "1000 '•5000 »

- 5 ppm

- 0.49 ?6• 0.056$

- 0.57 %

- 3 56

- 5 * 5 ? 6

- 0.16 %

- 0.03356- 1.09 56

Limit dependson amount taken

-157-

APEEMDIX II

OC

1* Br. ••!>• laraeintoam participated in the Srofessor M.I. Sana

ibBsorlal Synposiua held at Allahabad unireraity during Pebruary 5-12,

1972 and gaxe an invited talk entitled, "Spectra of Astrophyaical Inters*"*

2* Dr. H.A. Harasiinaani and Dr. M.V.R.K. llirty attended the

"Symposium on Spectroscopio Studies of Astrophyeical Interest" held at

the Centre of Advanced Study in Astronomy, Oamania Dotrereity, Hyderabad

during August 16-18, 1972* Dr. Naraslnfaam presented a paper entitled,

"Predissociatlons in Molecular Spectra", fir* Murty presented a paper on

"Some Optical Designs for Spectroscopic Systems Useful In Space Astro-

physical Applications'1*

3. Dr. N.A. Naraaimham and Dr. J« Bamamurti attended the Indo-

Soriet Conference on Solid State Materials at Indian Institute of Solenoe,

Bangalore, during December 11-16, 1972. Dr. Baoaaurti presented a paper

entitled, "Emission Spectra of Mixed Alkali Halides HaCliBr and RbBrll".

4* Dr. S.L.H.Q. Krishnamachari participated in the Seodsar on

"Remote Sensing of Natural Resources" held at the K.J. Sonaiya College

of Solenee on 7th and 8th October 1972 and delivered the key note address*

5. Dr. M.T.R.K. Marty attended the Workshop on Pcurier Optic*

organised by the Department of Electrical and Connunication Engineering

during Vorember 13-14, 1972 and gare the folloirlng talks i

l) Interferomstry with Lasers

ll) Diffxaction QratingB Productfi r Hdlography

-158-

6. Dr. V.B. Kartha and Dr. J* Bamamurti attended the "Huoleai?

Physios and Solid State Physios Symposium" held in Bombay during

?ebruai7 1-4, 1972* Dr. Kartha presented a paper entitled» "Infrared

Spectra of Oiol " and Dr. Banemurti presented a paper entitled,

"Luminieoence of MLzed Crystals of Potassium Chloride and Potaesiua

Bromide11*

7« Dr. MeV.H.K. Ifurty presented the following two papers at the

"All India Sysnpo.Bium on Applied Optics11 organleed by the Optical Society

of India in Delhi during 26-12-72 to 30-12-72.

i) k comparison of Two Image Botatlng Prleaa.

it) Theory of an Anastigmatlc Monochroiaator for Taouum Ultra-violet Region (with Nimai Chandra Das)

-159-

APBBNDK III

KBt-QBADEATB tHACHIHg. RESEARCH ABD TBAIHIHG TO OUISIDB PEBSQH1SEL

Dr. H*A<> laraaiohaa taught the special aubjeet apeotroaoopy

ooaprislng of papers 7 find YI of th« M.Se. ( Physios) degree course of the

Bombay tfoireraity.

Dr. V.B. Kartha gare a course of lecturea In Infrared and Ramn

Speotroacopy t o the Refreeher School In Chemlatry for Onirersity Lecturers

held by 3ARC In May-June 1972.

The following eelent iata continue to carry out re search work for

M.Sc/Hi.1) degree.

Sl«Ho9 Haiae - Subjeot Degree Unlreraity Guide

1* T.K. Balasubraaanian Ihyaica Ki.D. Bombay Dr. H.A. lara-ainhaa

2, O.I. Bbale " » " «3» S.V. (xranvurohit n u n H4o I . e . Chandola w " . " "5. S.A. Ahmad " • " "6« Snrt. P. Meenakshi Rajarao n « • H7» T.R. Saranathan w » H M8 . O.G. Mahaiaa " n " "9. I.Y. Venkltaehalam " R « Dr. SIMSK Cbarl10. Xum. M.N. Bhagrat " M.So. " " Dr. H.A. Kara-

alsh&B

The following staff nenbera hare submitted their theala for Hi.D.

degree a during the year 1972*Sl.Bo, Hana Degree Bhlrwltg

1. I.D. ftital a . B . (Chea) Ou3ara4Thasisi'^lbrationid Spectra of the Seuterated Dlhalogenated Benienea

8. 0. lakahoimrayana Ih*9« (aye) B«*ay Dr. I.A.

lueaias Klectronio Spectra of S2, CBO and 8g0

-160-

IBAUIHG 80 0UT3UB EEBSCSHEE

SL« go, VMM of the scientistand the institution

of ti^ Duration

1. Shrl T.I. lathak,Ghealstxy D»partm«nt,Bajasthan Gbireralty,Jaipur

2* Bhrl S.K. Katar*,Arnamaat Bssearch andJDeytlopment Establishment,Posaa-21

fluoreaoano* eaiaaionspectral studlea

Speotrooheslcalanalysis

16-2*72 to2-3-72

10-4-72 to21-4-72

Shri P.O. Taidya,Armanaaat Research andDeTelopment Establishment rPoona-21

Spectroohcmicalanalysis

10-4-72 to21-4-72

-161-

APEEHDIX IV

M8I OP PAPERS PUBLISHED IH JOqHHALS/SPBMrP'EED SOS POBLICAIIOg

8I.H0. Ti t l e of the paper

1. Mcsmal Co-ordinate Analysis ofCPJS and CP-D Molecules

2* Infrared Spectra of Cupferraaand Some Bare Earth Cupferratea

2. Compensation for Coma aadmorphie Effect In Double Mono-ehromators

4* Gomafree Double Monochromatorwithout Intermediate S l i t

5» Spin-Orbit Coupling Constant2 +

in the A rru State of 0 2

6* Emission Spectrum of PrO

Author/a

BomolaD'Cunha

Journal

J« Vol. Spaetroao.12, 282 (1972)

H.V. Ihakur, J» Inorg. andV.B. Kartha, Huol. CheBiiatxy,C.H. Kanekar, J^, 2831 (t972)& T.B. Maratbe

M.T.R.K. Murty App* Opt. 7ol.1972

M.V.B.K. Murty App. Opt. Vol.S » Oot. 1972

G,L. Bhale J« Mol«12, 17' ,

7* Vibrations! Analysis of

2500-3400 A Bands of 3 2

6* Estimation and measurement ofthe frequency of coarse gratingsby 'Moire* Fringe Techniques

9# Hoxual modes and group frequen-cies - Confliot cr Compromise?An in-depth vibrational analy-s i s of cyclohezanone

10* Yibrationel Spectrum of 1»2»4-O6C1-D_ and a noxnal oo-ordi-

nate analysis of i t s out-of-plane Tibrations

T.V. Tenksv Proc* Ind. Aead.tachalam, G. Scienos A. IXXTI,Krishnamurty 113 (1972)& H.A« JTara-simhasi

0* Lakehmina- Curr. S c i . , 41«rayana & H.A* 771 (1972)Naraeimhaa

M.V.R.K. Murty Opt. Engg., .11,,ft B.P. Shukla 20 (1972)

K, Fuhrer, Chenu BST. J 2 t

V.B. Kartha, 439 (1972)P.J. Krueger,E.H. Mantachft B.H. Jones

O.K. Ramamurty Speotro Ones.ft H.A. Hax»sim-A*ta 28 Ahaa 2253 (1972)

-162-

Bl»So. title of the paper

11. force Constant PerturbationProgramme - N.B.C.O.

12. Redundant Porcee and ComplianceConstants

Author/s

H. Puhrer,V.B. Kartha,G. Kidd,

Journal

National Bee.Council ofCanada Bulle-

P.J« Krueger, t i n Ho. 15(1S72)H.H«

H.S. Jones

Ch.V.8. Hama- J , Hoi* Speetroac.Chandra Bao 4&, 105 (1972)

13* She Vibrational Motions ofCyolopentanone

14* Effect of Field TheoreticalCorrections on X-ray Spectra

15. The - X 2 Z + Syetea of AlO

16. A Hew Electronic Transition

? 2 S + - A 2 7^ of AlO

V»B. Eartha,H.H. Mantach& B.H. Jones

T.V. Kriahnan& A.N. Nigam

MahaTir Singht M.D. Saksena

Mahavir Singh

Can* J. Chan,(accepted)

Proo. Ind. l ead .Sol .

(accepted)

Proo* Ind* Acad.Soi .

(accepted)

J . Phys. (B)(accepted)

17* Vibrational Spectra of Lihaloge-nated Benzenes - In-PlaneVibrations

18. Vibrational Spectra of Dihalogcnated Benzenes - Out-of -PlaneVibrations

H.D. Patel ,Y.B. Karthaft 5,A. Kara-sisihani

F.D. Pate l |T.3. Karthaft V.A. Hara-einiham

J. Hoi. Spectroac,

(accepted)

-do-

- 1 6 3 -

PAPERS PBESfcNTfcD AT 'PHS CONFERENCE/SYMPOSIA

SI .No. T i t l e of the paper

7.

Vibretion-Rotation-InveraionHamiltonian of Formaldehyde in

Vthe Excited State

2» Hear Infrared Bands of S_

3* Srsdissociations in MoleoulaxSpectra

Some Optical Designs forSpectroscopic Systems Usefulin Space Astrophyeical Appli-cations

Author/a

Ch.V.S. Baaa-chandra Eao &D.C. Moule

N.A. Barasinfaam

Conference/Symposia

Proc* 27th Symp.on MolecularStructure andSpectroecopy,The Ohio StateUniv. Columbus,Ohio, June 12-16,1972

-do-

H.A. Haraainihan Symposium onSpectroscopicStudies of Astro-physical Interest,Centre of AdvancedStudy in ABtronomy,Oamania Dnivareity,Hyderabad, 1972

H.V.R.K. Murty -do-

Spectra of AstrophyBical Interest H.A. Narasimham Professor M.H.Saha MemorialSympoaiuo,Allahabad

Emission Spectra of MLxedAlkali Balides NaClsBr andRbBril

Infrared Spectra and Coralencyof Bare-Earth Formates

T.B. Earths ftH.T. Thakur

Indo-SorietConference onSolid StateMaterials atBangaloreME CheaiBtry

Aligarh, 1972

L.»O.

8.

9.

10.

11.

, Tit le of the paper

Infrared Speotra and MoleoularMotion of Water in Alkali-12Molybdnophosphates

Infrared Speotra of CIO,

lualniscence of Mixed Crystalsof Potassium Chloride andPotassium Bromide

A comparison of two ImageRotating Prisms

-164-

Author/s

V.B. Kartha ftS. Dutta Hoy

Y.B. Kartha

M.V.H.K. llurty

Conference/Symposia

Ruol. Phys* ftSolid State Phys.Symposium, Chsn-digarh, 1972

Proc. Huol. Phys*and Solid StatePhys* Siymp.,Bombay, 1972

-do-

All India Sympo-sium on AppliedOptioe, Delhi ,1972

12. theory of an Anastignatie Bono- M.V.B.K. Ibirtychromator for Taouum UltraTiolet ft Hiaal ChandraRegion Saa

-do-

- 1 6 5 -

BABO BBPQBT3 BODUCBD

Tit le of the Report Author/s Report Mo,

Spectrochemical Analysis of High Pa SreeraoaBurty BABO-593Purity CadoiuB ft TJI.F. Kalnal

2. A Carrier Distil lation Method B»°» *»** « * BABO-621for th« Estimation of Man-Ear.- Km. P.S. KaznlkEarth Impurities in YgO

3* Speetrogrephic Analysis of Boron B.B. Vengsarkar BABC-432Hitride for Trace Impurities I . J . Machado ft

S.K. Malhotra

4* Speotrogzaphio Analysis of L.G. Chandola BABC-648Tantalum Oxide B.V. Subraoanian

ft Smt. T.S. Dixit

(A) An Intermittent A..0, AreMethod

(B) A D.C Arc Method

5e A Mew Carrier for Speotrogrephic B.M. Dli i t , B.T. Bent forAnalysis of Ag, Mo and Ca in Subramanian, P.P. PublicationUranium Khanna ft Sum. S.B.

Bindigikar

6. Speotrographlc Analysis of • • ? • Karanjikar Sent forTwenty One Trace Impurities * M.D. Saksena Publicationin High Purity Nickel Oxide

APEBHDH T

SEHYIOE AHAIXSIS ANDDESIGf AVD JABRIOAIICH OF OPTICAL EQUIPMENT TO DHIT8Off DtPARTMEHT OF ATOMIC EHKSQY AID OTHER WSTITUTICB3

-169-

Dlvislonal break up of service analyaia fog the year

S.Ho. Souroe No* °* No. of detezai-aamplea aatioaa

1* Uranium Metal Plant

2* Atomic Fuels Division

3. Chemical Engineering Division

4* Chemistry Division

5» Metallurgy Division

6. Analytical Chemistry Division

7* Reactor Engineering Division

8. Heavy Water Division

9* Health Physics Division

10* Isotope Division

11. Beaotor Operations Division

12* Technioal Physios Division

13* Electronics Division

14. Directorate of Radiation Proteotion

15* Variable Energy Cyclotron Project

16. Badioohemi8try Division

17. Cixus

18. Nuclear Physios Division

Department of Atomio Biergyt

19* Power Projeota Bigineering Division

20* Nuclear Fuel Coaplttc

21. Atomlo Minerals Division

1216

301

225

217

51

21

18

12

11

7

6

5

4

3

2

2

1

1

45

7

1

7262

2408

931

1341

122

162

59

28

18

40

58

24

4

24

6

12

4

1

405

7

4

-170-

~ _ Ho.of Ho. of detend-S.No. souroe aaapleB nations

22. Indian Bare Earths Ltd. 4 36

23. ELeotronics Corporation of India 4 4United

Universities & Other Institutional

24* S.W.I.R.P. Pondichery

25. Waltair (University)

26. National Physical Laboratory

27* I.I.T., Madras and Bombay

28. l&tkand Iron & Steel, Bombay

29. Industrial Tube Manufacturing,Bombay

50. Caxton ChesLoal Industries, Bombay

51. Solid State Physios Lab.

52. Instrumentation, Kbta

35. Andhra Pradesh Instruments

34* J*X» Synthetios, Bombay

5?. Century Rayons, Bombay

36. Mahtre Pen & Plastic Industries,Bombay

37* Central Fuel Reeearoh Institute

38. Utkal University

39* Shaw Wire Produots, Bombay

22

15

12

12

10

8

7

4

3

2

2

1

1

1

1

2297

178

242

30

54

24

90

16

7

32

18

8

2

9

1

7

1

13679

-171 -

AHALYTICAL JOBS uTOBgEAKEB BOB OOTSIBB 0BGA3IS&TI0HS

8 1 . ffo» Institution

1* Harro Industries Limited,Bombay

2. ifLorou Platers, Bombay

Mature of Job

Analysis of zinc samples

Analysis erf K 1 ( H )samples c 442/-

3.

4.

5.

6.

7.

e.

Century Eayon, Salyen

Power Projects EngineeringDivision| Bombay

Industrial 2ub« Ifeuaufaotu-rers (P) Ltd., Kalyan

Power Projeots EngineeringMvision, Bombay

Bajaettaan Atomie PowerProject, Kota, Bajastiaan

Instrumentation Limited,Kota, Rajasthan

Analysis

Analysissamples

Analysissamples

Analysissamples

Analysissamples

Analysissamples

of

of

of

of

of

of

seaples

steel

copper

steel

steel

platinum

fc.

is,

it.

Is.

b .

HE.

2500/.

300/-

615/-

310/-

168/-

990/-

-172-

undertaken by the Optical Workshop for otiier Mrialon of B.Jt.B.O.

DlTlBlOO

(1) Pobri-Perot plates

60 am dia. oad 16 sn thick

(2) OoncsYs Mirrors

57 sm dia. and H - 50 B B

150 on dia. and R - 1500 on

Dia. - 80 am

B - 210 am.

(4) PolleblBg of silioa tubaends, filters, windows etc.

(5)

(7)

(8) "

(9) Optical flata

14 on dia* 4 won thick

1 pair

2 HOB.

4 "

8 loa .

8 Hot.

10 Hoe.

2 HOB.

8 Hoe.

HuolcorItayaioa

N

HteithFhyaica

11

Metallurgy

Heavy Water

Biochemistryand FoodSsohnologjr

12 HOB.

2 Hos.

Ohemistiy

-173-

JOBS PHPERTAKEM BY OPTICAL WORKSHOP gQR QUTSIIE ORGAHISATIONS

Sl»Ho. Institution

1. Kesoxam Industries & CottonMill a Limited, Andhra Pradesh

2* Electronics Corporation ofIndia Ltd., Hyderabad

3» fhyaical Research Laboratory,Navxangapura, Ahmedabad

4. Regional Engineering College,Warangal .

5. Eumud Vldya Mandir, Msmkhurd

6» Electronics Corporation ofIndia Ltd., Hyderabad

Mature of job Charges

Cutting and pollening the Bs 201.85lithium fluoride crystalsInto windows

Supply of concave spheri- Rs 7992*60cal mirrore for uee inspectrophotometer

Supply of one pair of 8s 4620.00Fabry-Perot Reflectors

Supply of optical parallels Ss 418.20and standard wedges

1) Reflecting telescope On loan2) Terrestrial telescope3) Projection microscope

Supply of Reflection Rs8095/~gratings (replicas) -30 Nos,

7. Asian Paints (India) Ltd, Testing of 4 cryptometere Rs 65/-

-173-

JOBS OHPERTAKEN BY OPTICAL WORKSHOP FOR ODTSIIB ORGANISATIONS

S I . H o . Institution nature of job

1. Keeoram Industries & Cotton Cutting and polishing the Bs 201.85Mills Limited, Andhra Pradesh lithium fluoride crystals

into windows

2* Electronics Corporation of Supply of ccuca.a «poeri- St7992*60India Ltd-, Hyderabad cal mlrrore for use in

spectrophotometer

3. Physical Research Laboratory, Supply of one pair of Ks 4620.00Narrangapura, Ahmedabad Pabry-Perot Befleotcrs

4. Regional Engineering College, Supply of optical parallels Es 418.20Warangal and standard wedges

5. Kumud Vidya Mandlr, Mankhurd 1) Reflecting telescope On loan2) Terrestrial telescope3) Projection microscope

6* Electronics Corporation of Supply of Reflection Rs8095/-Indla Ltd*, Hyderabad gratings (replicas) -

30 Nos.

7. Asian Paints (India) Ltd* Testing of 4 cryptometers IU65/-