FISSION OF GOLD WITH 112-Mev C{sup 12} IONS: A YIELD-MASS AND CHARGE- DISTRIBUTION STUDY (thesis)

Fission prcduct cross sections were measured radiochemically and mass- spectrometrically for gold bombsrded with 112-Mev C/sup 12/ ions. Cross sections for 43 nuclides were measured for elements from nickel to barium. Thirty-six yields are either primary fission product yields (independent yields) or were corrected (with less than 25% correction) so as to represent independent yields. The independent yields were empirically systematized and a yield-mass curve was constructed. The yield-mass curve is compared with the yield-mass curves obtained from the fission of Bi with 22 and 190-Mev deuterons. The yield systematics indicate that the sum of the mass numbers of complementary fission products is 13 plus or minus 1 amu less tban that of the compound nucleus, and the sum of the charges of complemertary fission products is two units less than that of the compound nucleus. It is postulated that 9 plus or minus 1 neutrons and an alpha particle must have been emitted. Evidence is presented that at least three and possibly more of the neutrons are emitted prior to fission. The most probable charge of the fission products as a function of mass number was determined empirically. It is shown that from mass number 80 to mass number 111 the Equal Charge Displacement (ECD) and Constant Charge Ratio (CCR) rules predict the empirical values equally well. For masses less than 80 and greater than 120 the ECD and CCR rules are shown to be equally poor, as the empirical distribution is between them. The Minimum Potential Energy theory of charge distribution proposed by Present and modified and interpreted by Swiatecki is shown to predict the empirical points over the entire mass region studied (A = 66 to A = 135) within experimental error ( plus or minus 0.2 charge unlt). (auth