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Claudia Lederer

Status of the 62 Ni(n, g ) analysis. Claudia Lederer. n_TOF collaboration meeting, 15.-17. 12. 2010, Seville. Measurement. C 6 D 6 detection setup sample: highly enriched in 62 Ni, 2 cm Ø, 2 g 197 Au, 2 cm Ø, 0.6 g nat Pb, 2 cm Ø, 0.3 g nat C, 2 cm Ø, 5 g. Claudia Lederer.

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Claudia Lederer

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  1. Status of the 62Ni(n,g) analysis Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  2. Measurement • C6D6 detection setup • sample: highly enriched in 62Ni, 2 cm Ø, 2 g • 197Au, 2 cm Ø, 0.6 g • natPb, 2 cm Ø, 0.3 g • natC, 2 cm Ø, 5 g Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  3. Steps of data analysis • C6D6 calibration • normalization to proton intensity • dead time and coincidence correction • application of weighting functions • time-of-flight to energy calibration • Beam interception and neutron flux • Background corrections Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  4. Steps of data analysis • C6D6 calibration • normalization to proton intensity • dead time and coincidence correction • application of weighting functions • time-of-flight to energy calibration • Beam interception and neutron flux • Background corrections Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  5. ToF to energy calibration • Au spectrum: fit ER of low energy resonances in SAMMY (4.9 eV, 46.7 eV, 58.0 eV, 60.3 eV, 78.5 eV, 107.0 eV)* • moderation time t0 =0 and DO NOT SHIFT NTOF RESOLUTION FUNCTION • LGEEL* = 18694 ± 5 cm • LENDF = 18668 ± 14 cm *private communication GELINA to C. Massimi Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  6. 4.9 eV resonance in Au Flux MGAS (10B)* NWF_Nicola= 0.595 ± 0.001 NWF_Frank = 0.592 ± 0.001 Flux MCNPX** NWF_Nicola= 0.596 ± 0.001 Beam interception Data SAMMY calculation * Analyzed by C. Guerrero ** normalized to MGAS from 1-100 eV Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  7. 4.9 eV resonance in Au Flux MGAS (10B)* NWF_Nicola= 0.595 ± 0.001 NWF_Frank = 0.592 ± 0.001 Flux MCNPX** NWF_Nicola= 0.596 ± 0.001 Beam interception 1.15 keV resonance in Fe • Flux MGAS (10B)* NWF_Nicola=0.592 ± 0.005 • Flux MCNPX** NWF_Nicola=0.574  3% change!!! * Analyzed by C. Guerrero ** normalized to MGAS from 1-100 eV Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  8. Beam interception 1.15 keV resonance in Fe • Flux MGAS (10B)* NWF_Nicola=0.592 ± 0.005 • Flux MCNPX** NWF_Nicola=0.574  3% change!!! Fe yield (MCNPX flux) 4.9 eV normalization Fit of normalization * Analyzed by C. Guerrero ** normalized to MGAS from 1-100 eV Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  9. Flux 2009 Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  10. Flux 2009 + Flux 2003 Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  11. Background corrections Components: • sample independent  empty sample holder • in-beam-g  smooth background, fit background in SAMMY for each resonance • neutron scattering  most difficult correction and biggest background for 62Ni Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  12. Neutron sensitivity • en/eg3x10-5 for C6D6 detectors (Plag et al.) • en/eg ?? for experimental area Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  13. Neutron sensitivity • en/eg3x10-5 for C6D6 detectors (Plag et al.) • en/eg ?? for experimental area • measurement of Carbon sample (sel , sg ) Nibg= Niel_yield*Carbonmeasured/Carbonel_yield Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  14. Neutron sensitivity • en/eg3x10-5 for C6D6 detectors (Plag et al.) • en/eg ?? for experimental area • measurement of Carbon sample (sel , sg ) Nibg= Niel_yield*Carbonmeasured/Carbonel_yield • Example: 62Ni: ER= 4.6 keV, Gn=2.026 keV, Gg=2.374 eV  Gn/ Gg = 853 • calculate elastic yield with SAMMY Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  15. Neutron sensitivity Weighted Counts Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  16. Neutron sensitivity • Fitting the 4.6 keV resonance with pointwise BG Yield En (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  17. Neutron sensitivity • JENDL parameters: ER = 4600 eV, Gg=2.376 eV, Gn=2026 eV • Fit result: • subtracted background: ER = 4614 eV, Gg=1.892 eV • no background: ER = 4603 eV, Gg=2.721 eV Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  18. Neutron sensitivity • JENDL parameters: ER = 4600 eV, Gg=2.376 eV, Gn=2026 eV • Fit result: • subtracted background: ER = 4614 eV, Gg=1.892 eV • no background: ER = 4603 eV, Gg=2.721 eV • en/eg  3x10-5 for C6D6 detectors • en/eg  4x10-4 for experimental area Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  19. Neutron sensitivity • JENDL parameters: ER = 4600 eV, Gg=2.376 eV, Gn=2026 eV • Fit result: • subtracted background: ER = 4614 eV, Gg=1.892 eV • no background: ER = 4603 eV, Gg=2.721 eV • en/eg  3x10-5 for C6D6 detectors • en/eg  4x10-4 for experimental area • HOW GOOD IS THIS PROCEDURE ? Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  20. Neutron filters • W: 0.8 mm thick, ER =4, 20.6 eV • (Al: 30 mm thick, ER =34.7 keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  21. Neutron filters • W: 0.8 mm thick, ER =4, 20.6 eV • (Al: 30 mm thick, ER =34.7 keV) low energy bg in Ni time-correlated Carbon has some additional contribution possibly simulations help Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  22. Comparison of low energy part with evaluations Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  23. Comparison of low energy part with evaluations Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  24. Cross section and thermal • Extrapolation of data to thermal: fit yield with a+b/sqrt(E) sthermal= 14.5 barn Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  25. Cross section and thermal sthermal= 14.5 barn sthermal,res = 11.7 barn Yield data minus background SAMMY calclulation En (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  26. Cross section and thermal sthermal= 14.5 barn sthermal,res = 11.7 barn  see direct contribution Yield data minus background SAMMY calclulation En (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  27. Cross section and thermal sthermal= 14.5 barn sthermal,res = 11.7 barn No bg subtraction: sthermal= 15.6 barn sthermal,res = 16.5 barn Yield data SAMMY calclulation En (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  28. Data vs. JENDL: 1-10 keV 2000 bpd n_TOF JENDL-4.0 Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  29. Data vs. JENDL: 10 – 20 keV 2000 bpd Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  30. Data vs. JENDL: 20 – 50 keV 2000 bpd n_TOF JENDL-4.0 Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  31. Data vs. JENDL: 50 – 100 keV 2000 bpd n_TOF JENDL-4.0 Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  32. Data vs. JENDL: 100-150 keV 2000 bpd n_TOF JENDL-4.0 Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  33. Data vs. JENDL: 150 - 200 keV 2000 bpd n_TOF JENDL-4.0 Yield E (keV) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  34. Summary • all 62Ni data are processed • normalization in good agreement for different Wf and different resonances • Discrepancy between MGAS and MCNPX flux shape • Neutron scattering most crucial background • possible to extract cross section at thermal • Resonances can be identified up to approx. 200 keV • Data are more in favour of JENDL-4.0 (compared to ENDF/B-VII) Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

  35. THANK YOU FOR YOUR ATTENTION ! Claudia Lederer n_TOF collaboration meeting, 15.-17. 12. 2010, Seville

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