Intermediate structure of the cross section for fission of /sup 241/Am by neutrons with energy 0. 08--1. 3 MeV

The results of measurements of the cross section sigma/sub f/ for fission of /sup 241/Am by neutrons with energies E/sub n/ from 80 to 1350 keV are reported. In sigma/sub f/ (E/sub n/) as a function of energy we observe at E/sub n/ = 200, 300, 480, and 790 keV resonance-like structures with width GAMMA/sub b/approx. =70, 90, 120, and 190 keV, respectively. The characteristics of these structures manifest their connection, not with vibrational states in the intermediate minimum of the two-humped barrier as is believed at the present time, but with excited states of compound nuclei at a normal deformation delta/sub 0/approx. =0.25. The height of the /sup 242/Am fission barrier is B/sub f/ = 6.40 +- 0.05 MeV, and the barrier curvature is h-dash-bar..omega../sub f/ = 700 +- 50 keV.