Fission yield curves for slow-neutron fission of $sup 241$Am and $sup 241$Pu

The absolute cumulative yields of 40 fission fragments from slow-neutron fission of /sup 241/Am and /sup 241/Pu were obtained by radiochemical means, and a curve of mass yields was plotted. The number of fissions in samples was determined directly from the number of fission events in a small aliquot of the fissionable material placed on a mica track detector and exposed simultaneously to the same neutron flux as the main sample. The absolute disintegration rates of the radionuclides of interest were determined by means of a 4 pi BETA counter. Errors in the determination of fission yields do not exceed plus or minus 5%. Measured yields are compared with values given in the literature. Three fission systems, spontaneous fission STA/sup 242/Cm!, sub-threshold fission STA/sup 241/Am (n,f)!, and above-threshold fission STA/sup 241/Pu (n,f)!, with compound mass A/sub f/ = 242 are compared and discussed. The position of the fine structure for these systems does not depend on Z of the fissionable nucleus. The fine structure has a period of 4 to 5 mass units and fits masses 99 to 100, 105 to 106, 133 to 135, 139 to 140, and 144 to 145. (3 figures, 6 tables) (auth)