PSI 23-25.11.2015 CHANDA –workshop on target preparation ...PSI 23-25.11.2015 CHANDA –workshop...

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PSI 23-25.11.2015 CHANDA – workshop on target preparation – the needs and the possibilities


SINQ cooling water 7Be, 22Na, 88Y

Proton of 590 MeV and a

beam current of up to 2.4 mA.

2

SINQ target� 207Bi, 172Hf,� 173Lu, 194Hg,� 202Pb, 125Sb,� 106Ru, 44Ti

Copper beam dump

�44Ti, 53Mn, 26Al, 60Fe, 59Ni, 32Si, 60Co

SINQ Target Irradiation

Program-STIP44Ti, 53Mn, 26Al

Special irradiations positions with 590 MeV protons

V for 44Ti production

Bi for 205Pb production

“Useful” components

p-beam

Myon production station� Operation 1-3 years

� Source for 10Be

7Be


Cosmological Lithium problem

N_TOF:

Session 5: Results of experiments I

11:30 Measurements of the 7Be (n,cp) reactions: a big challenge for sample preparation and

experimental setups (M. Barbagallo, INFN Bari, Italy)

Tuesday, 24.11.2015

SARAF:

Session 6: Results of experiments II

15:30 Toward measurements of neutron interactions with 7Be and the primordial 7Li problem

(E.E. Kading, UConn, USA)

Institut Laue-Langevin (ILL)

�The measurement of the cross sections of this nuclear reactions at

different E will be performed in two different experiments: SARAF (10-

15 GBq) and N_TOF (~50 GBq)�Preparation of two 25 GBq 7Be targets

for the N_TOF project


Deposition techniques

Separation of 7Be

Molecular plating Vaporization of droplets

Backing material

Aluminum 5 µm Polyethylene 0.6 µm

Results

Schema of the presentation


Separation of 7Be

100 mL ion exchanger LEWATIT mixed bed

b

e

7Be (decay product 7Li)

and impurities such as 22Na, 110mAg, 88Y, etc...


Deposition techniques

Molecular plating Vaporization of droplets


Electrodeposition set-up

Copper cathode with stainless

steel placket

Platinum Wire Anode (+)

Catode (-)Power supply


3 4 5 6

1

10

100

1000

10000

100000

thickness = 5.8 µm

dE/dx = 0.5692 keV/(µg/cm²)

1581 µg / cm2

Max = 5.5 MeV FWHM = 0.02Area = 62059 cc


Cou

nts

Energy / MeV

241Am 241Am + ~5 µm Al

dE = 900 keV

� standard 241Am source

� 5.8 µm Al backing (1581 µg/cm2)

between the standard source and

the alpha detector.

Energy loss of 900 keV.

Al backing - thickness


Dummy target molecular plating onto 5 µm Al

Step 1: purification of Be.

This step aims to obtain a precipitate of Be(NO3)2 with minimal quantity of both H2O and HNO3.

Step 2: Be dissolution in 5 ml of isopropanol

Step 3: Electrodeposition of Be

Current of about 1 mA, for a total time of 50 minutes

7Be activity in the ED solution was

recorded every 10 min by taking an aliquot of

100 µl of the electroplating solution

0 10 20 30 40 50

0

20

40

60

80

100 Activity ED Solution Yield

Act

ivity

ED

Sol

utio

n (k

Bq)

Time (minutes)

Electrodeposition procedure


3 4 5 6

1

10

100

1000

10000

100000




Cou

nts

Energy / MeV

241Am 241Am + 5 µm Al Be deposited on Al

dE = 200 keV

Thickness = 1.2 µm

3 4 5 6

1

10

100

1000

10000

100000


Cou

nts

Energy / MeV

241Am

� deposited Be layer

between the standard source and

the alpha detector.

Energy loss of 200 keV.

� Thickness = 1.2 µm

Deposit layer thickness


Vaporization of droplets


4.6 4.8 5.0 5.2 5.4 5.6 5.8

1

10

100

1000

5.442 MeV

Energy, MeV

241Am 241Am + PE: dE = 57 keV

5.499 MeV

dE/dx(α-5.5 MeV in PE)

= 0.9481 keV/(µg/cm²)

Thickness PE = 0.64 µm

PE backing thickness


Conclusions

� We can provide different “exotic” isotopes:

� by their extraction from components of the proton accelerator at PSI, e.g. 26Al, 59Ni, 53Mn, 60Fe,44Ti, 10Be, 7Be 14C, 207Bi, 182Hf 146Sm, several Dy isotopes, 22Na, 88Y and many others….

� or produce them in dedicated p- or n- high energy (up to 560 MeV) irradiation experiments, e.g. 44Ti from V and 205Pb from Bi.

� We can produce targets out of them, with different size, shape and activity, using different techniques,

e.g. molecular plating and vaporization of different size droplets.

Molecular platingVaporization of droplets


The END………..

Acknowledgments:

Prof. Andreas Türler

David Piguet, Vögele Alexander

Laboratory for Radio- and Environmental Chemistry at PSI


Tantalum

Backing materials

Carbon, 1.5 µm

Nickel Aluminum, 1 µm

Platinum

SARAF

Carbon (flexible graphite), 75 µm


Carbon, 1.5 µm Aluminium, 1 µm

SARAF

Carbon (flexible graphite), 75 µm


1.5 µm (300 µg/cm2) C backing before molecular plating

C backing × 4.64 times enlargement

Grains have a diameter

of about 0.15 mm

3.5 4.0 4.5 5.0 5.5 6.01

10

100

1000

Cou

nts

Energy, MeV

Am-241 5.49 MeV

3.5 4.0 4.5 5.0 5.5 6.01

10

100

1000

5.26 MeV

Cou

nts

Energy, MeV

Am-241 C 1.5 um

5.49 MeVdE = 0.23 MeV

Energy loss of 230 keV

The energy loss of 5.5 MeV alphas in carbon is

dE/dx = 0.8 keV per µg/ cm2, hence for the carbon

backing with thickness of 300 µg/cm2 it is: 0.8 ×300 = 240 keV, same as measured.

SARAF


Target after electrodeposition× 4.64 times enlargementTarget after electrodeposition× 4.64 times enlargement,

1.5 µm C backing after molecular plating

SARAF


3.5 4.0 4.5 5.0 5.5 6.01

10

100

dE(C 1.5 µm)

= 230 keV

A2 / A1= 4

4.49 MeV. A1= 5

5.26 MeV. A2= 20

Cou

nts

Energy, MeV

241Am + 1.5 µm C: Area=26.1

241Am + 1.5 µm C + Be: Area=25.7

dE = 770 keV

The area of the deposited spot (inner circle) is 0.5 cm2. The tot area of the graphite

backing (large circle) is 2.5 cm2, thus the area of the backing not deposited (naked)

is 2.0 cm2. The ratio between the naked graphite and deposited area is 4.

� dE = 770 keV → three times thicker than the carbon backing,

hence around 900 µg/cm2

� Weight gain after the electro-deposition process is 190 µg which is

deposited onto 0.5 cm2, hence 380 µg/cm2.

deposition is not homogeneous

SARAF


Beryllium hydroxide: Be(OH)2

Beryllium oxide : BeO

Beryllium carbonate tetrahydrate:

BeCO3·4H2O

Beryllium carboxylates:

Be(RCOO)2

Beryllium oxide carboxylates:

Be4O(RCOO)6

Electrolysis of the solvent

Electrolysis of H2O

3.5 4.0 4.5 5.0 5.5 6.01

10

100

A2 / A1= 4

4.49 MeV. A1= 5

5.26 MeV. A2= 20

Cou

nts

Energy, MeV

241Am + 1.5 µm C: Area=26.1

241Am + 1.5 µm C + Be: Area=25.7

Physisorption of the solvent

SARAF


3.5 4.0 4.5 5.0 5.5 6.0

1

10

100

4.9 MeV ??

4.8 MeV ??

A2: 4.39 MeV

A2: 5.26 MeV

Cou

nts

Energy, MeV

241Am + 1.5 µm C + Be after 160°C 241Am + 1.5 µm C

3.5 4.0 4.5 5.0 5.5 6.0

1

10

100

A1 / A2 = 6.8

A2: 5.26 MeV

Cou

nts

Energy, MeV

241Am + 1.5 µm C + Be 241Am + 1.5 µm C + Be after 100°C

A1: 4.39 MeV

100 °C for 90 min

3.5 4.0 4.5 5.0 5.5 6.01

10

100

A2 / A1= 4

4.49 MeV. A1= 5

5.26 MeV. A2= 20

Cou

nts

Energy, MeV

241Am + 1.5 µm C: Area=26.1

241Am + 1.5 µm C + Be: Area=25.7

Physisorption of the solvent

160 °C for 60 min.

Shift of the low energy peak toward lower energy

and increase of the A1/A2 ratio

Supporting the thesis that this peak is related with

the attenuation due to some organic molecules

adsorbed on the backing surface

SARAF


4.5 5.0 5.5 6.0

1

10

100

1000

2.6 µm

1.0 µm

dE = 110 keV5.38 MeV

5.49 MeV

Cou

nts

Energy (MeV)

241Am 241Am + 1 mm Al

0.7 µm

ρAl

= 2.702 × 10-6 µg/cm3

1 µm Al backing before molecular plating

5.5 MeVα on Al (ρ = 2.702 x 10-6 µg/cm3) dE/dx = 0.5692 keV/(µg/cm²)

0.5692 keV/(µg/cm²) × 2.702 × 106 µg/cm3 = 154 keV/µmdE = 110 keV → Al thickness = 0.7 µm


1 µm target after molecular plating

3.0 3.5 4.0 4.5 5.0 5.5 6.01

10

100

1000

4.89 MeV

5.26 MeV

Cou

nts

Energy (MeV)

Am-241 Am+Al Am+Al+Be

dE = 370 keV

Thickness ≈ 2.2 µm

SARAF


3.0 3.5 4.0 4.5 5.0 5.5 6.01

10

100

1000

4.75 MeV4.89 MeV

5.26 MeV

Cou

nts

Energy (MeV)

Am+Al Am+Al+Be Am+Al+Be at 150°C

1 µm target after heating at 150 °C

SARAF

…however, it was chosen to use a 75 µm carbon backing, for safety reasons


Cosmological Lithium problem

�Thin and homogeneous 7Be layer

�on a thin backing

�The measurement of the cross sections of this nuclear reactions at

different E will be performed in two different experiments: SARAF (10-

15 GBq) and N_TOF (~50 GBq)


Dummy target: molecular plating onto 1.5 µm C

� The final target must contain about 11 GBq of 7Be, corresponding to 7.297 × 1016 atoms of 7Be.

� Be isotopes ratio of 1:1:1 (7Be: 9Be: 10Be) at the end of the beam time

� Total number of 2.19 × 1017 of 7,9,10Be atoms will be deposited on the carbon backing of the

final target

� About 2.63 × 1017 atoms (20% more ) of stable Be, in form of Be(NO3)2, were

precipitated from a 0.5 M HNO3 solution

� 130 µl of 7Be(NO3)2 solution (7Be in HNO3 1 M) were added to monitor the yield of the

different steps of the electrodeposition

� The electrolyte solution consists in isopropanol containing millimolar amounts HNO3

together with Be(NO3)2

Starting Be solution:

SARAF


Accelerator wasteShielding, construction material, targets, beam dumps, cooling

intensely exposed by high-energetic protons and secondary particlesdismounted, cooledready or foreseen for disposal

Waste components:Copper beam dump irradiated at the 590-MeV proton beam station at PSI, dismounted about 15 years ago

26Al, 59Ni, 53Mn, 60Fe, 44Ti Proton-irradiated carbon from target E

10Be, 7Be 14C, 3HMaterial from the SINQ facilityLead targets

207Bi, 182Hf, rare earth elements (e.g. 146Sm, several Dy isotopes) and lighter isotopes

STIP program (material research program)Stainless steel for 44Ti, 26Al, 53Mn production

SINQ cooling water7Be, long-lived isotopes from irradiated structure material (22Na, 88Y and many others)

Special irradiationsThe SINQ facility offers the possibility to irradiate materials with 590 MeV protons at special positions.Tended experiments for isotope production can be offered

V for 44Ti productionBi for 205Pb production

Irradiation with 71 MeV protons (injector 2) and up to 590 MeV neutrons (NAA, PNA)

Isotope production possibilities at PSI

PSI 23-25.11.2015 CHANDA –workshop on target preparation ...PSI 23-25.11.2015 CHANDA –workshop...

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