Zirconium capture measurements: INFN Bari N. Colonna G. Tagliente INFN Trieste K. Fujii P.M. Milazzo C. Moreau ITN Lisboa L.Marques P.Vaz R in Paris Zirconium capture measurements: data analysis results, perspectives

Physics case s-process analysis of great interest in stellar modeling (e.g. evolution of Red Giant stars) nuclear reactor design purpose nuclear waste transmutation 90 neutron magic number (N=50) Act as a bottle neck for the reaction flow towards heavier elements 90, 91, 92, 93, 94 Low-neutron capture cross sections, predominantly of s-process origin (existing data have uncertainties larger than 10%) 93 radioactive isotope One of the major long-lived fission products (T½ = 1.5 Myr) Used in reactor’s structural materials 96 r-process only Relevant in the study of pulsing AGB stars

Physics case, Nuclear Astrophysics (n,g) x-sections of Zr Bottleneck in the s-process flow at N=50 neutron magic number Small x-sections Normalization of s-process abundance Probing the neutron exposure and neutron flux in Red Giant Stars TOF 08

Zr capture Yields Zr Yield Overall background Stable isotopes, 2003 Natural radioactivity of the sample

Estimated resonance parameters E, Γg, Γn Resonance analysis Normalization 197Au 4.9eV Resonance Fit Zr-92 data 1 2 3 4 N.F.(92Zr)=0.6219 SAMMY fit of 92Zr 1 2 3 4 Estimated resonance parameters E, Γg, Γn

Resonance analysis typical examples 90 91 96 94Zr En=58.7keV 94 … multiple scattering correction, Doppler broadening and instrumental resolution were included in the analysis

Data analysis Sntof 14% lower than the previous data Gnntof 7% lower than the previous data

Data analysis Sntof 19% lower than the previous data Gnntof 3% lower than the previous data

Data analysis Sntof 14% lower than the previous data Gnntof 1% lower than the previous data

Data analysis Sntof 4% higher than the previous data Gnntof 3% higher than the previous data

Data analysis Sntof 25% lower than the previous data Gnntof 12% lower than the previous data

Data analysis Mughabghab 2006 Mughabghab 1986

Energy range investigated(KeV) Data analysis Energy range investigated(KeV) n_TOF RRR(KeV) Jendl3.3 90Zr 3.9 - 66 3.9 - 300.9 91Zr 0.16 - 26 0.16 - 30.6 92Zr 2 – 40 2 – 120 94Zr 2.2 - 74 2.2 - 90 96Zr 0.17 – 42 0.3 – 96

Data analysis MACS @ 30 KeV Zr (En range KeV) nTOF data (mb) Jendl 3.3 Correction factor (k) 90 (3.9-66 ) 14.6 17.2 0.85 91 (0.16-26) 32.6 37.8 0.86 92 (2-40) 25.8 30.4 94 (2.2-74) 26 23.5 1.1 96 (0.17-42) 6.2 11.1 0.6

Data analysis MACS @ 30 KeV Zr nTOF data (mb) Corrected by k Jendl 3.3 90 18.5 18.1 21.2 91 36.6 36. 41.85 92 39.7 37.7 44.3 94 27.4 27.6 24.9 96 7.5 6.9 12.4

Data analysis MACS @ 30 KeV Zr nTOF data (mb) Bao 90 18.1±1 21±2 91 51.6±2 60±8 92 37.7±2 33±4 94 27.6±1 26±1 96 7.5±0.4 10.7±0.5

Data analysis open questions Isotope En (eV) K with 96Zr K Diff % 91 159.4 0,383 0,02 182.0 8,45 8,44 -0,08 292,7 141,4 130,2 7,73 449,9 4,84 5,27 8,09 681,7 83,6 94,6 -13,1 893,3 27,2 26,9 1,29 3862,9 121,6 125,5 3,09 90 3864,4 71,8 76,9 6,65 4008,4 151,6 139,4 -8,78 96Zr Analysis

Data analysis open questions 91 on 91 sample 91 on 96 sample En = 681.7 eV ΔS/S ~ 13% En = 893.3 eV ΔS/S ~ 1% not related to wrong sample components definition

(almost) ready to publish how to proceed? A paper for each isotope (because of the difference in Gg) Two papers of the Astrophysics implication of all stable isotopes