1. n_TOF annual meeting 13-15 December 2011, Lisbon
Analysis of 63Ni(n,g)
Claudia Lederer
University of Vienna
n_TOF annual meeting December 2011, Lisbon

2. Claudia Lederer n_TOF annual meeting, Lisbon
Motivation
63Ni branching point in weak s process in massive stars
64Zn
66Zn
67Zn
65Zn
63Cu
64Cu
65Cu
66Cu
62Ni
63Ni
64Ni
65Ni
core He burning, kT=25 keV, Nn~106 cm-3
Claudia Lederer n_TOF annual meeting, Lisbon

3. Claudia Lederer n_TOF annual meeting, Lisbon
Motivation
63Ni branching point in weak s process in massive stars
64Zn
66Zn
67Zn
65Zn
63Ni MACS crucial for expected 63Cu abundances !!
63Cu
64Cu
65Cu
66Cu
62Ni
63Ni
64Ni
65Ni
Pignatari et al. (2010)
core He burning, kT=25 keV, Nn~106 cm-3
C shell burning, kT=90 keV, Nn~1011 cm-3
Claudia Lederer n_TOF annual meeting, Lisbon

4. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni measurement (20 mm Ø)
samples measured (protons for filter runs in brackets):
Configuration
thickness (a/b)
protons (x1017)*
purpose
63Ni
2.846e-3
18.9 (3.3)
cross section
62Ni
6.203e-3
9.7 (1.1)
background
197Au
0.584e-3
normalization
Sample holder -
2.6 (1.0)
Carbon
84.55e-3
0.6 (1.9)
background n-scatt
Empty
1.6 (0.6)
* dedicated pulses, extracted by TTOFsort
Claudia Lederer n_TOF annual meeting, Lisbon

5. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni sample
Original material (TU Munich, G. Korschinek, T. Faestermann):
62Ni sample irradiated in thermal reactor (in 1984 and 1992)
total mass: mg
enrichment in 63Ni: ~13 % (= mg)
contaminants: ~15.4 mg 63Cu
After chemical separation at PSI (D. Schumann):
NiO powder, 1156 mg (919 mg Ni)
63Ni/62Ni=0.134 (=108.4 mg)
Container: PEEK (C20H12O3)
<0.01 mg 63Cu
PEEK container had 180 mg total mass
Claudia Lederer n_TOF annual meeting, Lisbon

6. Claudia Lederer n_TOF annual meeting, Lisbon
Detector calibration
calibration sources: Cs (Eg=662 keV), Y (Eg=898,1836keV), AmBe (Eg= 4.44 MeV)
C6D6  detection of compton edge
simulation of energy deposition in C6D6 liquid
GEANT4 geometry by IFIC Valencia
assume resolution function s2=a*E+b*E2
Y source (898,1836keV)
Claudia Lederer n_TOF annual meeting, Lisbon

7. Claudia Lederer n_TOF annual meeting, Lisbon
Detector calibration
Calibration:
calibration needs to be good up to approx. 9 MeV (Sn 63Ni !!)
last energy point of sources: 4.44 MeV:
63Ni
Claudia Lederer n_TOF annual meeting, Lisbon

8. Claudia Lederer n_TOF annual meeting, Lisbon
Detector calibration
Calibration:
calibration needs to be good up to approx. 9 MeV (Sn 63Ni !!)
last energy point of sources: 4.44 MeV
 Use also 62Ni and 63Ni amplitude spectrum (strong transitions at Sn)
Claudia Lederer n_TOF annual meeting, Lisbon

9. Claudia Lederer n_TOF annual meeting, Lisbon
Statistics
Claudia Lederer n_TOF annual meeting, Lisbon

10. Claudia Lederer n_TOF annual meeting, Lisbon
Statistics
Claudia Lederer n_TOF annual meeting, Lisbon

11. Claudia Lederer n_TOF annual meeting, Lisbon
Weighted Spectra:
WFs:
Ethres=250 keV
IFIC Geometry
Claudia Lederer n_TOF annual meeting, Lisbon

12. Claudia Lederer n_TOF annual meeting, Lisbon
Weighted Spectra
Claudia Lederer n_TOF annual meeting, Lisbon

13. Claudia Lederer n_TOF annual meeting, Lisbon
Beam Off background
63Ni
Dummy (1 pos from 63Ni)
62Ni (2 pos from 63Ni)
57Fe Campaign
58Ni Campaign
Claudia Lederer n_TOF annual meeting, Lisbon

14. Claudia Lederer n_TOF annual meeting, Lisbon
Beam Off background
dedicated
parasitic
Claudia Lederer n_TOF annual meeting, Lisbon

15. Claudia Lederer n_TOF annual meeting, Lisbon
Beam Off background
Claudia Lederer n_TOF annual meeting, Lisbon

16. Claudia Lederer n_TOF annual meeting, Lisbon
Normalization
4.9 eV resonance in Au
Normalization:
Au(4.9 eV): 0.601
Au(4.9 eV) 2009: 0.661
Fe(1.15 keV) 2009: 0.629
Claudia Lederer n_TOF annual meeting, Lisbon

17. Claudia Lederer n_TOF annual meeting, Lisbon
Normalization
4.9 eV resonance in Au
Normalization:
Au(4.9 eV): 0.601
Au(4.9 eV) 2009: 0.661
Fe(1.15 keV) 2009: 0.629
Cross section at thermal:
Au: 91.8 b (98 ENDF)
62Ni: 12.6 b (14.1 ENDF)
62Ni(2009): 14.1 b (Emin=1eV)
Energy dependence of beam interception?
Claudia Lederer n_TOF annual meeting, Lisbon

18. Claudia Lederer n_TOF annual meeting, Lisbon
Normalization
Experimental Beam Interception 2011 (F. Belloni)
eV:  7.2 % lower
1-10 eV:
100 eV – 1keV:  7.9 % lower
Claudia Lederer n_TOF annual meeting, Lisbon

19. Claudia Lederer n_TOF annual meeting, Lisbon
Normalization
Experimental Beam Interception 2011 (F. Belloni)
eV:  7.2 % lower
1-10 eV:
100 eV – 1keV:  7.9 % lower
Experimental Beam Interception Au and Fe 2011
thermal (2011): 6.7 % lower (wrt ENDF xs)
4.9 eV: (2009), (2011)
1keV: (2009)  5 % lower
Claudia Lederer n_TOF annual meeting, Lisbon

20. Claudia Lederer n_TOF annual meeting, Lisbon
62Ni 2011 vs. 62Ni 2009
2011
2009
Claudia Lederer n_TOF annual meeting, Lisbon

21. Claudia Lederer n_TOF annual meeting, Lisbon
62Ni 2011 vs. 62Ni 2009
2011
2009
Claudia Lederer n_TOF annual meeting, Lisbon

22. Claudia Lederer n_TOF annual meeting, Lisbon
62Ni 2011 vs. 62Ni 2009
2011
2009
Claudia Lederer n_TOF annual meeting, Lisbon

23. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni yield
63Ni-sample
62Ni-sample
Claudia Lederer n_TOF annual meeting, Lisbon

24. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni yield
59Ni
63Ni-sample
62Ni-sample
Claudia Lederer n_TOF annual meeting, Lisbon

25. Claudia Lederer n_TOF annual meeting, Lisbon
59Ni contamination ~ 0.06%
Claudia Lederer n_TOF annual meeting, Lisbon

26. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni yield
63Ni-sample
62Ni-sample
Claudia Lederer n_TOF annual meeting, Lisbon

27. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni yield
63Ni-sample
62Ni-sample
Claudia Lederer n_TOF annual meeting, Lisbon

28. Claudia Lederer n_TOF annual meeting, Lisbon
63Ni yield
63Ni-sample
62Ni-sample
Claudia Lederer n_TOF annual meeting, Lisbon

29. THANK YOU FOR YOUR ATTENTION

30. Detector calibration + resolution
calibration needs to be good up to approx. 9 MeV (Sn 63Ni !!)
last energy point of sources: 4.44 MeV
 Use also 62Ni and 63Ni amplitude spectrum (strong transitions at Sn)
Claudia Lederer n_TOF annual meeting, Lisbon

31. Detector calibration + resolution
calibration needs to be good up to approx. 9 MeV (Sn 63Ni !!)
last energy point of sources: 4.44 MeV
 Use also 62Ni and 63Ni amplitude spectrum (strong transitions at Sn)
Claudia Lederer n_TOF annual meeting, Lisbon

32. Detector calibration + resolution
calibration needs to be good up to approx. 9 MeV (Sn 63Ni !!)
last energy point of sources: 4.44 MeV
 Use also 62Ni and 63Ni amplitude spectrum (strong transitions at Sn)
Claudia Lederer n_TOF annual meeting, Lisbon

33. Claudia Lederer n_TOF annual meeting, Lisbon
Weighting functions
Simulation of monoenergetic g-rays (1e7 particles each):
100, 200, 500, 700, 800 keV and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 MeV
Claudia Lederer n_TOF annual meeting, Lisbon

34. Claudia Lederer n_TOF annual meeting, Lisbon
Weighting functions
Simulation of monoenergetic g-rays (1e7 particles each):
100, 200, 500, 700, 800 keV and 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 MeV
g threshold 250 keV
WFs for samples
Au, big Au
58,62,63Ni
Claudia Lederer n_TOF annual meeting, Lisbon