Delayed neutron emission from mass-separated fission products

Thesis. Delayed neutron characteristics of six fission product nuclides were determined using a mass separator operated on-line with a nuclear reactor. Beta-decay half-lives were- measured using neutron multiscaling techniques for the precursors /sup 88/Br, /sup 89/Br, /sup 98/Kr, /sup 93/Kr, /sup 137/I, and / sup 138/I. The observed half-lives were 16.52 plus or minus .17 seconds, respectively.. Energy spectra were measured for delayed neutrons emitted in the beta-decays of /sup 17/N, /sup 137/I, /sup 93/Kr , and /sup 93/Rb. The spectra of neutron emissions in the mass 93 parentdaughter decay chain were observed using a moving tape collector to effect isobaric separation. Two different types of /sup 3/He- filled neutron spectrometer were used to determine the spectra; a proportional counter with risetime discrimination electronics, and a high resolution ionization chamber. The measured delayed, neutron spectra using both detector types are presented, and the results compared, where possible, with other reported measurements. (auth)