1. LAL, Orsay IDEA meeting14-15.04.2005 Validation of excitation functions of 60 Co and 68 Ge 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: kornoukhov@itep.ru kornoukhov@mail.ru

2. LAL, Orsay IDEA meeting14-15.04.2005 Plan of the report Activation at sea level Cosmic rays at sea level Review of Ge(n,x) 60 Co and Ge(n,x) 68 Ge excitation functions Objectives of the proposal Layout of experiment Production rates of 60 Co and 68 Ge Uncertainties of the experiment

3. LAL, Orsay IDEA meeting14-15.04.2005 Isotopes production rate (activation) dN/dt = N target *   (E)*  (E)dE  (E) – excitation function  (E) – hadrons (neutrons + protons) flux at sea level

5. Codes used to calculate excitation functions… CodeAuthor, labUsed modelsEnergy, GeV CEM95S.Mashnik, Dubna Exciton INC (Dubna), Weiskopf- Eving evaporation model,.. 0.01 - 5 CASCADEV.S.BarashenkovExciton INC (Dubna), Weiskopff- Eving evaporation model, fission < 1000 HETCK.C.Chandler, T.W.Armstrong, ORNL, TN INC Bertini and Weiskopff&Eving evaporation model < 3.5 LAHETR.E.Prael, LANL, CA INC Bertini/ISABEL, Weiskopff&Dresner evaporation model, fission.. Bertini: <3.5 ISABEL: < 1.0 NUCLEUST.Nishida et al., JAERI INC Bertini, JAERI fission model< 3.5 QMDK.Niita et al., JAERI Quantum-molecular dymamic model, Weiskopff&Eving evaporation model < 5.0

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

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

8. Excitation functions of production of the isotope Ge68 at interaction of NEUTRONS with nuclei-targets Nat Ge, 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

9. Excitation functions of production of the isotopes Ge68 and Co60 at interaction of PROTONS with nuclei-targets Nat Ge, Ge70 and Ge76. Comparison of calculations using the codes SHIELD (INR RAS) and LAHET (ITEP) with experimental data. N.Sobolevsky and A.Denisov, INR RAS, Dec. 2004

10. Excitation functions of production of the isotope Ge68 at interaction of PROTONS with nuclei-targets Nat Ge, Ge70, Ge74 and Ge76. Comparison of calculations using the codes SHIELD (INR RAS) and LAHET (ITEP). N.Sobolevsky and A.Denisov, INR RAS, Dec. 2004

11. LAL, Orsay IDEA meeting14.04.2005 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.

12. Irradiation of thin targets U10 Synchrotron at ITEP: – Proton energy: 40-10000 MeV; – Beam section: a circle of ~  10 mm; – Intensity: ~(1  2)  10 11 protons per pulse; – Extraction runs: 1-4 50-ns bunches spaced 150 ns apart.

13. LAL, Orsay IDEA meeting14-15.04.2005 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 70 Ge, 72 Ge, 73 Ge, 74 Ge, 76 Ge sample ). 2. Three sets of the Ge targets are placed at one position (30 o – 60 o ) and irradiated (one by one) with three different energy of protons: 115 MeV, 256 MeV and 800 MeV.

14. LAL, Orsay IDEA meeting14.04.2005 A schematic of arrangement of the Ge- samples around the proton-irradiated W target

15. LAL, Orsay IDEA meeting14-15.04.2005 Measured and calculated neutron spectrum at different angles (if E p = 800 MeV)

16. 60 o seems to be better option Particles Spectrum at 30 o, 90 o, and 150 o

17. LAL, Orsay IDEA meeting14-15.04.2005

18. LAL, Orsay IDEA meeting14-15.04.2005 Number of nuclei produced and activity, if 10 15 protons (W) & 1 g

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

20. LAL, Orsay IDEA meeting14-15.04.2005 About isotopic composition of the 76Ge target Enrichment of 76 Ge-sample – 99.82% (to avoid 70 Ge influence): 74 Ge < 0.12%; 73 Ge < 0.03%; 72 Ge < 0.02%; 70 Ge < 0.01% GERDA: 76 Ge = 88.2%, 74 Ge = 11.8%; 73 Ge = 0.095%; 72 Ge < 0.01%; 70 Ge < 0.01%

21. LAL, Orsay IDEA meeting14-15.04.2005 Scheme of Ge-68 decay  tot ~ 0.03*  det ~ 0.0006 bkg = 1 - 100 d -1

22. LAL, Orsay IDEA meeting14-15.04.2005 Scheme of Co-60 decay  tot ~ 2*  det ~ 0.04bkg = 1 - 100 d -1

23. LAL, Orsay IDEA meeting14-15.04.2005 Time to get 100 pulses with HPGe measurement, days

24. LAL, Orsay IDEA meeting14-15.04.2005 Experiment’s uncertainties

25. LAL, Orsay IDEA meeting14-15.04.2005 CONCLUSION In ITEP: a)Accelerator + experimental site with certified neutrons flux (for E p = 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 E n < 800 MeV). Estimation of total production rates. 4. Total uncertainty of the experiment ~ 30%.