Resonance structure in the fission of (235U + n)

Abstract A new multilevel reduced R-matrix analysis of the neutron-induced resonance cross sections of 235 U has been carried out. We used as a constraint in the analysis the angular anisotropy measurements of Pattenden and Postma, obtaining a Bohr-channel (or J, K channel) representation of the resonances in a two-fission vector space for each spin state. Hambsch et al. , have reported definitive measurements of ( 235 U the mass- and kinetic-energy distributions of fission fragments of ( 235 U + n) in the resonance region and analyzed their results according to the fission-channel representation of Brosa et al. , extracting relative contributions of the two asymmetric and one symmetric Brosa fission channels. We have explored the connection between Bohr-channel and asymmetric Brosa-channel representations. The results suggest that a simple rotation of coordinates in channel space may be the only transformation required; the multilevel fit to the total and partial cross sections is invariant to such a transformation.