New evidence of an intense scission neutron source in the Cf-252 spontaneous fission

The neutron energy-angular distributions relative to the fragment direction of Cf-252 (SF) were analysed. The results of three independent experiments being in reasonable agreement allows the conclusion that a (30 +/- 5)% neu tron surplus exists at similar to 900 relative to the direction of the movi ng fragments, which can not be accounted for with the assumption that all n eutrons are emitted from fully accelerated fragments. This experimental fac t required the incorporation of neutron emission from an additional source of neutrons. Angular and energy distributions of these additional neutrons were evaluated using data from an experiment performed at IRMM several year s ago and were compared with the results in literature, (C) 2001 Elsevier S cience B.V. All rights reserved.