FO UM IN MIXED SION PRODUCTS In a given sample containing the fission praducts of Pu or 0798 it . on is necessary to have a theoretical messure of the (Sr®® « Sr®°)/ (total fission activity) ratic as a functicn of time. WT Hurter and Ballou have derived aunroximate excressions for total Ung ot 7 5a OY. fission product activity as a functicn of time. in minutes, these equations are: tad cee og, If it is expressed A(t) = (156000)¢73:78 l day ¢t <b days “aT A(t) = (2800 )t74°9 4 days< t < 100 days zea A(t) = (2-16x10%)t7*°®9 “TP rt 123° At 130 days after burst time, Sr®* and Sr®° contribute 10% and 0.35 we | 2 100 days ¢ t < 3 years respectively to fission product.activity. The ratio of for J any time is then calculated from the Sr half lives and the A(t) formulae. This ratio has been plotted in Fig. A-l. yes With a knowledge of the percent contribution of each Sr isotope to re 78 i total activity, the disintezration rates of Sr®® and Sr°° at a time are readily obtained using the A(t) data. The ratio of Sr Sr®* has been plotted fram 1-1000 days in this manner in Pig. vn. z be ae z 4g ie S“ a my of nef: ; ye ‘ . me SX UNCL, SSIZILu 00131986.04 103 107b