1. Neutron activation of materials relevant for GERDA Institut für Kern- und Teilchenphysik March 12th 2009 GERDA-meeting - Padova Alexander Domula

2. 2 ŒNeutron Introduction/Activation Experiments Neutron-Activations with 14MeV Neutrons ŽActivation of copper and stainless steel components

3. 3 Neutron Activation Experiments Neutron sources: radioactive sources -radioactive -sources ( 210 Po, 241 Am,…) - 7 Li(,n) 10 B, 9 Be(,n) 12 C, 13 C(,n) 16 O,… - 241 Am- 9 Be source E n midd = 4,46 MeV nuclear fission -Maxwell- or Wattspectra; E (  max ) ≈ 1 MeV

4. 4 Neutron Activation Experiments accelerators -charged particle reactions  7 Li(p,n) 10 B (Q=-1,646 MeV)  2 H(d,n) 3 He (Q=3,266 MeV)  3 H(d,n) 4 He (Q=17,586 MeV; E n ≈14,064 MeV) -Bremsstrahlung  (,n)-reactions cosmic ray reactions

5. 5 Neutron Activation Experiments inelastic scattering  74 Ge(n,n‘) 74 Ge * Neutron capture  74 Ge(n,) 75m Ge

6. 6 Neutron Activation Experiments fast Neutron activation  63 Cu(n,) 60 Co  76 Ge(n,p) 76 Ga  59 Co(n,p) 59 Fe  65 Cu(n,2n) 64 Cu

7. 7 Neutron Activation Experiments competing reaction channels one product of different isotopes one product of different reaction channels

8. 8 Neutron Activation Experiments spectroscopy of Neutron fields dosimetry measurement of Neutron-reaction cross-sections exploring nuclear level schemes material analysis

9. 9 Activation Experiments at 14 MeV TUD Neutron Generator motivation: GERDA meeting at Nov 2008 „Cosmogenic Radionuclides in stainless steel and copper“ G.Heusser, M. Laubenstein 1. stainless steel 2. copper

10. 10

11. 11 Activation Experiments at 14 MeV TUD Neutron Generator chemical composition of 1.4571 stainless steel (X6CrNiMoTi17-12-2) Element CSiMnPSCrMoNiTi Max. fraction % 0,081,002,000,0450,015 18,52,513,50,7 + Fe + rest consists of Fe activation experiments at neutron facility at FZD Rossendorf -stainless steel components (1.4571):  Fe, Mo, Ni, Ti activated elementwise

12. 12 Activation of stainless steel components (Fe) end irradiation Feb 12th 2009, 16:00 short living nuclides -Feb 12th 2009, 17:33:15, t L = 580 s E [keV]Nuclid 846,856-Mn 1811,3856-Mn 2114,0456-Mn 2524,1856-Mn 3371,2856-Mn

13. 13 Activation of stainless steel components (Fe) long living nuclides -Feb 27th 2009, 11:42:13 t L = 256‘979 s E [keV]Nuclid 121,3857-Co 319,7951-Cr 510,99Annihilation 810,7658-Co 834,954-Mn

14. 14 Activation of stainless steel components two ways to get 54 Mn  56 Fe(n,2np) 54 Mn  54 Fe(n,p) 54 Mn not mentioned  14 MeV Neutrons!

15. 15 cross section vs. Neutron Flux   activation 2,6 times higer for 56 Fe(n,2np) 54 Mn reaction  54 Fe(n,p) 54 Mn also important

16. 16 Activation of stainless steel components (Mo) E [keV]Nuclid 140,0299-Mo / 99m-Tc 180,599-Mo 235,4995m-Nb 765,7695-Nb 777,9396-Nb 934,5492-Nb 1199,8996Nb 1204,8891m-Nb 1477,3893m-Mo long living nuclides t L = 165‘840 s

17. 17 Activation of stainless steel components (Ni) short living nuclides t L = 1‘750 s E [keV]Nuclid 121,2157-Co 136,8857-Co 127,7557-Ni 510,8Annihilation 810,5858-Co 847,1556-Co ? 1377,8457-Ni 1758,2757-Ni 1920,557-Ni

18. 18 Activation of stainless steel components (Ti) E [keV]Nuclid 158,7247-Sc 174,7748-Sc 510,9446-Sc 888,9948-Sc 983,3348-Sc 1037,3546-Sc 1120,4947-Sc 1212,8248-Sc 1312,1248-Sc long living nuclides t L = 170‘465 s

19. 19 Activation of Copper E [keV]Nuclid 366,1465-Ni 510,86Annihilation 1115,765-Ni 1346,1864-Cu 1482,1865-Ni end irradiation Feb 12th 2009, 16:00 short living nuclides -Feb 12th 2009, 17:07:24, t L = 1‘239 s

20. 20 Activation of Copper long living nuclides -Mar 2nd 2009, 12:03:33 t L = 169‘995 s E [keV]Nuclid 121,0257-Co 135,0357-Co 510,76Annihilation 608,50214-Bi 809,7358-Co 1171,9660-Co 1331,0560-Co 1460,3040-K 1763,63214-Bi 2504,83  60-Co 2613,64208-Tl

21. 21 cobalt in copper ?

22. 22 Cross sections 59 Co(n,x) 59 Co(n,2n) 58 Co only when 59 Co(n,) 56 Mn is visible

23. 23 Activation of Cobalt short living nuclides -t L = 265 s E [keV]Nuclid 510,92Annihilation 810,7258-Co 846,7656-Mn 1099,2859-Fe 1291,8559-Fe 1811,3156-Mn 2113,9756-Mn 2524,0956-Mn 3373,8456-Mn

24. 24 Summary Neutron activation is a powerful tool to investigate radioisotope production First samples of Fe, Ni, Mo, Ti, Cu and Co have been activated with 14 MeV Neutrons 54 Fe(n,p) 54 Mn reaction can‘t be neglected for 54 Mn production on iron Observed 57 Co by copper activation due to nickel within Cu

25. 25 Next steps activation of 1.4571 stainless steel sample provided by G. Heusser work towards cross section measurement activation of chrome ? Activation of Argon ? Activation of any other Material of interest for GERDA ?