Neutron spectrum from 252Cf spontaneous fission

Includes bibliography.Measurements have been made of the neutron spectrum from the spontaneous fission of 252Cf in the restframe of the fragment by simultaneous observation of the neutron time-of-flight and the fragment velocity. The fragments were detected by means of thin film plastic scintillators in which the scintillation pulse-height response was verified to be a linear function of fragment velocity. The measurements of the neutron spectrum in the restframe of the fragment are compared with previous work and are found to deviate significantly from the predicted observations of the simple form of the evaporation model