Data are presented for the pulse-height distribution of fission fragments which results from the spontaneous fission decay of the 14 ms ~Am isomer, indicating a normal asymmetric yield-mass distribution for the fragments. The partial cross section for production of the isomer by 12 MeV deuteron bombardment of 24~Pu and the spontaneous fission half-life are determined to be 8~=3 #b and 16.7±1.5 ms, respectively. A search was made for isomers which decay by spontaneous fission produced in deuteron bombardments of 23~Th, 23sU, ~sU, 289Pu, ~lAm and 24~Am and proton bombardment of 243Am. Upper limits are established for spontaneous fission decay with half-lives in the ranges 10-20 #s to 1 h. A comparison is made between experimental data from deuteron bombardments of ~4~Pu and the results of calculations based on the compound-statistical model. E NUCLEAR REACTIONS 242Pu(d, 2n), (cl, f), E = 12 MeV; measured a~(delayed)/a~(prompt). Enriched target. 2Z2Th, 235U, ~3~Pu, 241Am, Z4ZAm(d, xn)(d, f), E = 12 MeV; 2~aAm(p, xn)(p, f), E= 13 MeV; measured upper limits er~(delayed)/ar(prompt). Enriched targets. RADIOACTIVITY 24~Am isomer [from 2~2Pu(d, 2n)]; measured Tff(sf), E~ragment-Spectrum.
Enriched target.