High resolution measurements of time-dependent integral delayed neutron spectra from thermal neutron induced fission of 235U

Composite delayed energy spectra from epithermal neutron induced fission of 235U have been measured for twelve delay-time intervals extending from 0.12 to 150 s. These data provide a comprehensive set of composite spectra with enhanced sensitivity to neutrons emitted in less than 1 s following fission. Extensive comparisons between these measurements and the composite spectra obtained by summation technique are presented and discussed herein.