Fission fragment energy correlation measurements for the thermal neutron sub-barrier fission of 231Pa

Abstract

Abstract Fission fragment mass and kinetic energy distributions and mass-versus-energy correlations have been measured for the thermal neutron induced fission of 231 Pa. The global mass distribution and the mass distribution for selected kinetic energy events show fine structure with a mean period of ≈ 2.5 amu. The peak/valley ratio of the mass distribution is 2271 ± 854 compared to 554 ± 31 for 235 U. The dip ΔE K values at symmetric fission for 231 Pa and 235 U are 14.8 ± 4.2 and 20.6 ± 1.1 MeV respectively. The 〈 E K 〉( μ H ) for μ H ≈ 125–135 is flatter than for 235 U.