Near barrier fission channels ( Jπ, K) in 238U for spins Jπ=0 +, 1 −, and 2 + from (e, e′f) angular correlation measurements

Abstract

Complete in- and out-of-plane fission fragment angular correlations for 238U have been measured in (e, e′f) coincidence experiments for momentum transfers q eff=0.20 and 0.28 fm − and excitation energies ω=5.5–15 MeV. A combined analysis with previously extracted E1 and E2/E0 multipole strength distributions yields strength distributions for all 6 near barrier fission channels ( J π , K) = (0 +, 0), (1 −, 0), (1 −, 1), (2 +, 0), (2 +, 1), and (2 +, 2) up to ≈8 MeV. An estim ate of the respective fission barriers, deduced from the increase of the fission cross sections, is given.