1

Measurement of excitation yields of low energy prompt -ray from proton bombardment of 48Ti foil

VN Bondarenko AV Goncharov a IM Karnaukhov VI Sukhostavets A G Tolstolutskiy SN Utenkov KV Shebeko

NSC KIPT Kharkov Ukraine

1-st Technical Meeting on Development of Reference Database for Particle-Induced Ray Emission (PIGE) Spectroscopy 16-20 May 2011 IAEA Headquarters Vienna

National Scientific Centre National Scientific Centre Kharkov Institute of Physics and TechnologyKharkov Institute of Physics and Technology

a Chief scientific investigator

2

Kharkov on a map

3

Kharkov Institute of Physics and Technology

1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of

theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including

investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of

electron and ion accelerators including the largest in the USSR electron linear accelerator were built

1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies

1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes

4

The basic fields of research work at NSC KIPT

Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials

Plasma physics and controlled fusion Nuclear physics physics of electromagnetic

interactions physics and engineering of electron accelerators

Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration

Theoretical physics

5

The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels

That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database

Motivation

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

2

Kharkov on a map

3

Kharkov Institute of Physics and Technology

1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of

theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including

investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of

electron and ion accelerators including the largest in the USSR electron linear accelerator were built

1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies

1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes

4

The basic fields of research work at NSC KIPT

Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials

Plasma physics and controlled fusion Nuclear physics physics of electromagnetic

interactions physics and engineering of electron accelerators

Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration

Theoretical physics

5

The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels

That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database

Motivation

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

3

Kharkov Institute of Physics and Technology

1928 ndash founded with aim of developing urgent fields of research 1931 ndash the cryogenic laboratory first in the USSR was organized 1932 ndash 1937 Landau formed an internationally known school of

theoretical physics 1934 ndash the first in the world radar was constructed 1937 ndash Van de Graaff accelerator (25 MeV) first in the USSR was built Post-war years ndash activity in the field of atomic energy including

investigations of thermonuclear fusion 1960-1970 ndash many unique experimental facilities namely a number of

electron and ion accelerators including the largest in the USSR electron linear accelerator were built

1972 ndash 1991 the Institute executed functions of a main organization in the USSR in the field of radiation materials science and radiation technologies

1991 - present time ndash the Institute constitutes an essential part of research complex of Ukraine especially in the field of atomic industry material science accelerator equipment and new sources of energy for civil and defense purposes

4

The basic fields of research work at NSC KIPT

Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials

Plasma physics and controlled fusion Nuclear physics physics of electromagnetic

interactions physics and engineering of electron accelerators

Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration

Theoretical physics

5

The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels

That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database

Motivation

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

4

The basic fields of research work at NSC KIPT

Solid-state physics Physics of radiation effects and radiation materials science Technologies of materials

Plasma physics and controlled fusion Nuclear physics physics of electromagnetic

interactions physics and engineering of electron accelerators

Plasma electronics and physics of high-current beams Physics and engineering of heavy charged particle accelerators New methods of acceleration

Theoretical physics

5

The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels

That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database

Motivation

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

5

The PIGE technique is widely used for quantitative analysisFor example the technique can be used for determination of Ti in the strengthened by fine dispersed TiO2 ferritic steels which are developing for fast reactors PIGE measurements can be simultaneously performed with PIXE ones using HPGe detector In comparison with the PIXE technique the PIGE one is characterized by larger depth of analysis in steels

That is only one of reasons why the experimental cross-section values of 48Ti(p)49V 48Ti(p)49V+49Ti(pn)49V reactions are necessary for PIGE database

Motivation

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

6

- Acceleration voltage 05 hellip 35 МeV - Energy spread 007 - Ion beam current of the direct output 90 μА - Ion beam current after the bending magnet 20 μА - Accelerated ions ndash H+ He+

NSC KIPT ldquoESU 5rdquo Van de Graaff accelerator

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

7

RF source of gas ions H+ He+ N+

NSC KIPT ldquoSokolrdquo Van de Graaff accelerator

- Acceleration voltage 02 hellip 2 МeV - Energy spread 007

- Ion beam current of the direct output 50 μА

- Ion beam current after the bending magnet 10 μА

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

8

Experimental beam lines of the

ldquoSOKOLrdquo facility

1 High pressure vessel of the accelerator2 Beam-bending magnet (analysis of energy and mass) 3 Beam line 1(PIXE PIGE)4 Beam line 2(beam in air biological materials PIXE PIGE)5 Beam line 3(for implantation)6 Beam line 4(ldquouniversal chamberrdquo PIXE RBS NRA PIGE

ERD)7 Beam line 5(microbeam PIXE PIGE RBS) Diameter of ion beam asymp 3 microm

1 2

3

4

5

6

7

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

9

Experimental setup for low energy -emission measurements

Experimental chamber with100 m Be-window

HPGe detector (20 mm26 mm)

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

10

Necessity of proton energy averaging at the cross-section measurements The choice of target thickness for the averaging

(p) ndash reactions on medium nuclei are usually followed with a large number of very narrow resonances corresponding to excited states of residual nuclei

Typical level widths of the 49V nucleus (product of the 48Ti(p) reaction) range from several to several tens electron-Volts (TW Burrows Nuclear Data Sheets for A=49)

So detail measurements of ldquotruerdquo energy dependences for the cross sections of such reactions are practically impossible under conditions when a primary beam has a finite energy spread and a target has a finite thickness

But from standpoint of practical use in PIGE technique such detailed measurements are not necessary because energy spread of beam rises quickly in analyzing substance

In this connection cross-sections measured with some averaging on proton energy are more useful Obviously averaging interval would be larger than distances between resonances In practice this interval is determined by thickness of a target used at cross section measurement

On the other hand the target thickness would not be too large to avoid indistinctness of resonance structure of the measured cross-sections at least near strong resonances

At the preliminary measurements we used the Ti target with 978 enrichment of the 48Ti isotope Thickness of the target was equal to about 065 m

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

11

Isotope composition of the used 48Ti target

46Ti 47Ti 48Ti 49Ti 50Ti

02 10 978 07 03

Na Mg Al Si Ca Cr Fe Ni Cu Pb

0005 0013 0007 0007 0013 0006 0005 0006 0005 00005

Impurities

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

12

Measurement of the target thickness by RBS technique

200 400 600 8000

1000

2000

3000

4000

5000

Ti

Ta Ta

E

TiTa model Ta

Cou

nts

Channel number

RBS spectra from Ta target and 48Ti target on Ta backing

E1

Ti Ta-backing

= 1700

t

kE0-E

He+ E0=16 MeV

Ta

= 1700

kE0

He+ E0=16 MeV

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

13

Treatment of the RBS spectrometry data

Kinematical factor of elastic scattering

2

22

1

sin1cos

kkTa

He

M

M MHe is 4He atom mass MTa is Ta atom mass

Correct value of the Ti target thickness from RBS spectrometry data was determined from

numerical solution of the system of two equations for E1 and t

t is the Ti target thickness (atcm2) E1 is the He ion energy (MeV) on TiTa interface t =371018 аtсm2 5

978 48Ti

STi(E) is the stopping power (MeVcm2at) of He ion

in Ti substance vs ion energy E

1

0

0

1cos

kE

EkETi

E

ETi ES

dEtES

dEt

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

14

Beam-target-detector geometry at the excitation function measurement

= 450

Ti

Ta-backing

100 m Be - window

Proton beam

HPGe - detector

= 900-rays

Guard ring- 300 V

At the geometry -ray absorption in a backing has no influence on measurement results

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

15

Calibration of the γ-ray detection system efficiency ε(Eγ)

The calibration was carried out with the standard 133Ba 152Eu and 241Am sources at the geometry used for the cross-section measurements (here Eγ is the γ-ray energy)

With that the ordinary expression was used liveAEnEN Nγ is the full-energy peak area (counts)

n(Eγ) is the quantum yield of used nuclide for the energy Eγ

(quantumdecay) A is the activity of the source (decays)

τlive is the live time of measurement (s) It is well known that the efficiency may be formally present as the product of several factors

EEE crystalabsorber4 Ω is the solid angle of the detector

εabsorber le1 is the factor describing the γ-ray absorption in substance layers between the source and detector crystal (in our case these absorption layers are the output window of target chamber and the input window of the detector)

εcrystal le1 is the factor describing the γ-ray absorption in material of the crystal Using the last equation we may formally introduce the ldquoeffectiverdquo solid angle Ωe(Eγ) of the detector via equivalent relation

4

EE eε

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

16

Proton energy loss in the Ti target

The energy loss ΔEp was determined from numerical solution of the

equation

p

pp

E

EETip ES

dEt 0

0cos

t is the Ti target thickness φ is the beam incidence angle taking from normal to the target Eop is the primary proton beam energy

The interval of energy averaging at cross-section measurement is equal to the ΔEp

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

17

1000 1500 2000 2500 30000

100

200

300

400

500

600

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

18

Data reduction

The averaging differential cross-section dσγdΩ of -ray production from the 48Ti(p)49V reaction was determined from the general expression

cosft

d

dkNN ep

Nγ is the number of counts in the full-energy peak k is the ratio between the live time and the exposure time Np is the number of protons incident upon the target Ωe=Ωe(Eγ) is the effective solid angle of the detector f is the relative content of 48Ti in Ti target substance t is the Ti target thickness (atcm2) φ is the beam incidence angle taking from normal to the

target

Since 23010 cmb e

QN p

Q is the integrated beam charge (μC) measured during exposition e is the elementary charge (160210-13 μC) then we come to the final expression ftEkQ

N

srb

d

d

e

cos

106021 17

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

19

900 1000 1100 1200 1300 1400 1500 1600 17000

2

4

6

8

10

12

14900 1000 1100 1200 1300 1400 1500 1600 1700

0

2

4

6

8

10

12

14

dd

bs

r

E=906 keV

Proton energy keV

E=623 keV

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

Differential cross-sections for the production of 623 and 906 keV -rays

from the reactions 48Ti(p)49V lab=900 (Preliminary results)

Vertical error bar is statistical mean-square error only Horizontal error bar is equal to a half of proton energy loss in target

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

20

Differential cross-sections for the production of 623 and 906 keV -rays from the reactions 48Ti(p)49V for proton energies ranging between 10 and 16 MeV at the laboratory angle of 900 have been measured

Summary

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

21

Further steps

bull to prepare thin (01mgcm2) targets of natural Tibull to measure differential cross-sections for the production of 623 keV and 906 keV -rays from the reactions

48Ti(p)49V at energies lt 1412 keV (threshold of 49Ti(pn)49V) and

48Ti(p)49V+49Ti(pn)49V at energies gt 1412 keV up to 3 MeV

Measurement perspectives

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

22

1000 1500 2000 2500 3000 35000

100

200

300

400

500

600

1362 keV

Q=2000 CE

p=1050 keV

Target 48Ti Ta

KX Ta

KX Ta

15293 keV

623 keV

906 keV

Cou

nts

Channel number

lab

72-

52-

32-

49V0

90639

152928

906 keV

623 keV 1529 keV

The typical spectrum of low-energy -ray from the 48Ti target

23

Thanks for your attention

23

Thanks for your attention