Measurements of Energy Dependence of Average Number of Prompt Neutrons from Neutron-Induced Fission of ²³⁵U, ²⁴¹Am and ²⁴³Am From 0.5 to 12 MeV

Abstract

The energy dependence measurements results of average number of prompt neutrons from neutron-induced fission of ²³⁵U, ²⁴¹Am, ²⁴³Am and total gamma-rays energy for ²³⁵U and ²⁴³Am from 0.5 to 12 MeV are presented. The measurements were carried out with neutron beam from uranium target of electron linac of All-Union Scientific Research Institute of Experimental Physics using time-of-flight technique on 28.5m flight-path. The neutrons and gamma-rays from fission were detected by a big liquid scintillator detector (BLSD) loaded with gadolinium, events of fission — by parallel plate avalanche detector for fission fragments. Measurements of energy dependence of ${{\bar{v}}_{p}}$, Eγtot and determination of BLSD efficiency (relative to ${{\bar{v}}_{p}}$ and Eγtot for ²⁵²Cf ) were carried out simultaneously. Least squares fitting results give ${{\bar{v}}_{p}}{\mkern 1mu} {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} 3.05{\mkern 1mu} {\mkern 1mu} + {\mkern 1mu} {\mkern 1mu} 0.14^\circ {\mkern 1mu} En$ for ²⁴¹Am and ${{\bar{v}}_{p}}{\mkern 1mu} {\mkern 1mu} = {\mkern 1mu} {\mkern 1mu} 3.20{\mkern 1mu} {\mkern 1mu} + {\mkern 1mu} {\mkern 1mu} 0.15^\circ {\mkern 1mu} En$ for ²⁴³Am.