High resolution measurement of neutron inelastic scattering and (n,2n) cross-sections for 52Cr

摘要

Cross-sections were measured for gammas produced by neutron inelastic scattering and (n,2n) reactions on 52Cr using the white neutron spectrum of GELINA with the time-of-flight technique at the 200 m flight-path station. The full energy range, from the inelastic threshold up to 18 MeV was covered in one experiment with an unprecedented neutron energy resolution of 1.1 keV at 1 MeV and 35 keV at 10 MeV. The gamma rays were detected with large volume HPGe detectors. The flux was determined with a 235U fission chamber based on the 235U(n,F) standard cross-section. A Cr2O3 sample was used with a 52Cr/Cr concentration of 99.85% wt. Inelastic gamma production cross-sections were measured for 12 transitions, at least one transition from each level up to an excitation energy of 3.77 MeV. Based on the adopted level scheme of 52Cr, the total inelastic and the level cross-sections were constructed. A total uncertainty smaller than 5% was obtained for the total inelastic cross-section up to 10 MeV. The (n,2n) gamma production cross-section was measured for the 749.06 keV and 1164.4 keV transitions from 51Cr. Results are compared with earlier experimental works and model calculations performed with the TALYS code. Calculations with the default parameters of TALYS show in general rather good agreement with the present data.