Fission neutron spectrum of Pu239

Abstract

The energy distribution of prompt and delayed neutrons originating from thermal fission of Pu239 has been measured from 0.5 to 8 Mev with nuclear plates. The spectrum obtained shows a maximum intensity in the 0.6- to 0.8-Mev region and an exponential slope of 4.3±0.2 Mev per decade of intensity in the energy region above 2 Mev. © 1952 The American Physical Society.