V.F. Batyaev, I.V. Kirpichnikov, V.N. Kornoukhov* , Yu.E.Titarenko, A.A.Vasenko, V.M. Zhivun

LAL, Orsay IDEA meeting 14-15.04.2005

Validation of excitation functions of 60Co and 68Ge production on germanium isotopes

• V.F. Batyaev, I.V. Kirpichnikov, V.N. Kornoukhov*, Yu.E.Titarenko, A.A.Vasenko, V.M. Zhivun

ITEP (Moscow, Russia) A.Caldwell,…

• MPI (Munchen, Germany)• S.Schoenert,...

• MPIK (Heidelberg, Germany)

(*) for contacts: [email protected] [email protected]


Plan of the report

• Activation at sea level• Cosmic rays at sea level• Review of Ge(n,x)60Co and Ge(n,x)68Ge

excitation functions• Objectives of the proposal• Layout of experiment• Production rates of 60Co and 68Ge • Uncertainties of the experiment


Isotopes production rate (activation)

dN/dt = Ntarget*(E)*(E)dE

(E) – excitation function

(E) – hadrons (neutrons + protons) flux at sea level

Codes used to calculate excitation functions…Code Author, lab Used models Energy, GeV

CEM95 S.Mashnik, Dubna

Exciton INC (Dubna), Weiskopf-Eving evaporation model ,.. 0.01 - 5

CASCADE V.S.Barashenkov Exciton INC (Dubna), Weiskopff-Eving evaporation model, fission

< 1000

HETC K.C.Chandler, T.W.Armstrong,

ORNL, TN

INC Bertini and Weiskopff&Eving

evaporation model

< 3.5

LAHET R.E.Prael,

LANL, CA

INC Bertini/ISABEL, Weiskopff&Dresner evaporation model, fission..

Bertini: <3.5

ISABEL: < 1.0

NUCLEUS T.Nishida et al., JAERI

INC Bertini, JAERI fission model < 3.5

QMD K.Niita et al., JAERI

Quantum-molecular dymamic model, Weiskopff&Eving

evaporation model

< 5.0

ISABEL-simulated excitation functions for 68Ge and 60Co production in Ge isotopes

10 100 1000 100000,1

1

10

100

The ISABEL code

68 G

e p

roduction, m

b

Proton energy, MeV

Target nucleus

Ge70 Ge72 Ge73 Ge74 Ge76

SHIELD-simulated excitation functions for 68Ge and 60Co production in Ge isotopes

10 100 1000 100001

10

100

The SHIELD code

68 G

e p

rod

uctio

n,

mb

Proton energy, MeV

Target Nucleus

Ge70 Ge72 Ge73 Ge74 Ge76

10 100 10000.1

1

10

100

Cro

ss s

ectio

n, m

b

Neutron energy, MeV

Ge70(n,X)Ge68 SHIELD (INR RAS) LAHET (ITEP) ISABEL (Majorana)

10 100 10001

10

Cro

ss s

ect

ion

, mb

Neutron energy, MeV


10 100 10000.1

1

10

Cro

ss s

ect

ion

, mb

Neutron energy, MeV


Excitation functions of production of the isotope Ge68 at interaction of NEUTRONS with nuclei-targets NatGe, Ge70, Ge74 and Ge76.

Comparison of calculations using the codes SHIELD (INR RAS), LAHET (ITEP) and ISABEL (Majorana White Book).

N.Sobolevsky and A.Denisov, INR RAS, Dec. 2004

10 100 10000.1

1

10

100

Cro

ss s

ectio

n, m

b

Proton energy, MeV

NatGe(p,X)Ge68 Calc. SHIELD code (INR RAS) Exp. T.Horuguchi et al,

Int.J.Appl.Rad.Isot.34(1983)1531

100 10000.01

0.1

1

10

Cro

ss s

ect

ion

, mb

Proton energy, MeV

Ge70(p,X)Co60 SHIELD (INR RAS) LAHET (ITEP) Exp. L.Batist et al. Preprint

LINP No.746, Leningrad, 1982.

100 1000

0.01

0.1

1

10

Cro

ss s

ect

ion

, mb

Proton energy, MeV

Ge76(p,X)Co60 SHIELD (INR RAS) LAHET (ITEP) Exp. L.Batist et al. Preprint

LINP No.746, Leningrad, 1982.

Excitation functions of production of the isotopes Ge68 and Co60 at interaction of PROTONS with nuclei-targets NatGe, Ge70 and Ge76.

Comparison of calculations using the codes SHIELD (INR RAS) and LAHET (ITEP) with experimental data.


10 100 1000

10

100

1000

Cro

ss s

ect

ion

, mb

Proton energy, MeV

Ge70(p,X)Ge68 SHIELD (INR RAS) LAHET (ITEP)

10 100 10000.1

1

10

Cro

ss s

ect

ion

, mb

Proton energy, MeV


10 100 10000.1

1

10

Cro

ss s

ect

ion

, mb

Proton energy, MeV


Excitation functions of production of the isotope Ge68 at interaction of PROTONS with nuclei-targets NatGe, Ge70, Ge74 and Ge76.

Comparison of calculations using the codes SHIELD (INR RAS) and LAHET (ITEP).


LAL, Orsay IDEA meeting 14.04.2005

Objectives of the proposal

1. Determination of production rate of the reactions (for En < 800 MeV).

2. Estimation of total production rates of Ge-68 and Co-60 on Ge isotopes.

3. Verification of models and codes. Selection of adequate one.

4. Estimation of the excitation functions.

Irradiation of thin targetsU10 Synchrotron at ITEP:

– Proton energy: 40-10000 MeV;

– Beam section: a circle of ~ 10 mm;

– Intensity: ~(12)1011 protons per pulse;

– Extraction runs: 1-4 50-ns bunches spaced 150 ns apart.


Strategy of the experiment

There are two approach how to run

the experiment:

1. Three sets of the Ge targets are placed at three different positions/angles (a set means 70Ge, 72Ge, 73Ge, 74Ge, 76Ge sample).

2. Three sets of the Ge targets are placed at one position (30o – 60o) and irradiated (one by one) with three different energy of protons: 115 MeV, 256 MeV and 800 MeV.

LAL, Orsay IDEA meeting 14.04.2005

A schematic of arrangement of the Ge-samples around the proton-irradiated W target

LAL, Orsay IDEA meeting 14-15.04.2005 Measured and calculated neutron spectrum at

different angles (if Ep = 800 MeV)

10 100 1000

0.00

0.02

0.04

0.06

0.08

0.10

Particle Spectra from W target

Ep=800MeV, 30odirection

Flu

x (

1/(

p*l

nE

*d))

E (MeV)

Neutrons Protons - +

10 100 10000.00

0.02

0.04

0.06 Particle Spectra from W target


Flu

x (

1/(

p*l

nE

*d))

E (MeV)


10 100 10000.00

0.02

0.04

0.06

Particle Spectra from W target


Flu

x (

1/(

p*l

nE

*d))

E (MeV)


60o seems to be better option

Particles Spectrum at 30o, 90o, and 150o



Number of nuclei produced and activity, if 1015 protons (W) & 1 g

70 72 73 74 7660Co-30 5.18E+06 6.41E+06 4.74E+06 4.40E+06 5.02E+0660Co-90 2.54E+06 1.60E+06 1.06E+06 3.60E+05 -60Co-150 9.76E+05 6.04E+05 1.23E+06 2.40E+05 9.34E+0468Ge-30 1.32E+08 3.45E+07 2.22E+07 1.08E+07 6.89E+0668Ge-90 2.01E+08 3.22E+07 1.29E+07 5.50E+06 2.55E+0668Ge-150 2.37E+07 3.33E+06 1.22E+06 7.20E+05 2.34E+05Activity(1/day)

70 72 73 74 7660Co-30 1.87E+03 2.31E+03 1.71E+03 1.58E+03 1.81E+0360Co-90 9.13E+02 5.77E+02 3.80E+02 1.30E+02 -60Co-150 3.51E+02 2.17E+02 4.44E+02 8.64E+01 3.36E+0168Ge-30 3.38E+05 8.83E+04 5.69E+04 2.76E+04 1.76E+0468Ge-90 5.15E+05 8.23E+04 3.30E+04 1.41E+04 6.52E+0368Ge-150 6.06E+04 8.52E+03 3.11E+03 1.84E+03 5.98E+02

Isotopic composition of enriched Ge (by V.P.Kovach, Svetlana) Zelenogorsk 23.11.2004

Ge isotopes, natural abundance

70 72 73 74 76

20.52% 27.4% 7.76% 35.34% 7.76%

Ge isotopes, after centrifuge cascade (simulation)

0.0000% 0.0089% 0.0798% 12.4577% 87.45%

GeF4

0.02% 0.11% 0.46% 96.55% 2.86%

96.11% 3.57% 0.12% 0.19% 0.01%

0.37% 96.29% 2.91% 0.42% 0.01%

0.05% 1.71% 96.52% 1.67% 0.05%

Ge metal

0.005% 0.01% 0.045% 7.02% 92.92%

0.005% 0.005% 0.02% 3.63% 96.34%

0.005% 0.005% 0.02% 0.59% 99.38%

0.01% 0.02% 0.03% 0.12% 99.82%

0.01% 0.02% 0.06% 13.13% 86.6%

0.005% 0.015% 0.03% 6.6% 93.35%


About isotopic composition of the 76Ge target

Enrichment of 76Ge-sample – 99.82% (to avoid 70Ge influence):

74Ge < 0.12%; 73Ge < 0.03%; 72Ge < 0.02%; 70Ge < 0.01%

GERDA: 76Ge = 88.2%, 74Ge = 11.8%; 73Ge = 0.095%; 72Ge < 0.01%; 70Ge < 0.01%


Scheme of Ge-68 decaytot ~ 0.03* det ~ 0.0006 bkg = 1 - 100 d-1


Scheme of Co-60 decay tot ~ 2* det ~ 0.04 bkg = 1 - 100 d-1

LAL, Orsay IDEA meeting 14-15.04.2005 Time to get 100 pulses

with HPGe measurement, days

Ge-70 Ge-72 Ge-73 Ge-74 Ge-76

60Co-30 1.4 1.1 1.5 1.6 1.4

60Co-90 2.8 4.4 7 20 -

60Co-150 7 12 6 29 75

68Ge-30 0.5 1.9 2.9 6.0 9.5

68Ge-90 0.3 2.0 5.1 12 26

68Ge-150 2.8 20 54 90 279

LAL, Orsay IDEA meeting 14-15.04.2005 Experiment’s uncertainties

Parameter Max uncertainty, %

1 Protons intensity 6

2 Neutrons intensity 15

3 Neutrons spectrum 20

4 Contribution from impurities

in the material of the target

1

5 Yield of -lines 10

6 Efficiency 10

7 Stat. Error (only Ge detector)

(if Ge detector + NaI +AC)

17

10

Sum 34/30


CONCLUSION

In ITEP: a)Accelerator + experimental site with certified neutrons

flux (for Ep = 800 MeV)b) Titarenko’ group involved in transmutation of long-lived

SNF isotopes.In the framework of the project will be done:

1. Verification of different models and codes. Selection of adequate one.

2. Estimation of the excitation functions.

3. Determination of production rate of the reactions (for En < 800 MeV). Estimation of total production rates.

4. Total uncertainty of the experiment ~ 30%.

Documents

V.F. Batyaev, I.V. Kirpichnikov, V.N. Kornoukhov* , Yu.E.Titarenko, A.A.Vasenko, V.M. Zhivun