CHARGE DISTRIBUTION IN FISSION - FRACTIONAL CUMULATIVE FISSION YIELDS OF 143BA AND 144BA FROM THERMAL-NEUTRON-INDUCED FISSION OF 235U

Rapid chemical separations of Cs and Ba from La and Ce have been used to measure half-lives and cumulative yields of Ba143 and Ba144 from thermal-neutron-induced fission of U235. The half-lives are 13.2±0.3 sec for Ba143 and 11.9±0.3 sec for Ba144. The yields, each expressed as a fraction of the total chain, are 0.88±0.06 and 0.78±0.06 for Ba143 and Ba144, respectively. Charge distribution for A=144 can be represented by a Gaussian distribution with width parameter σ=0.52±0.02 and Zp=56.09±0.05. For A=143, σ=0.58±0.05, and Zp=55.87±0.05, in agreement with previously reported values. Evidence is presented that charge distribution as determined from yields of several isotopes of the even-Z elements Xe, Ba, Kr, and Sr can be satisfactorily represented by a single Gaussian distribution with σ=0.56. A possible even-odd effect in nuclear charge distribution from fission of U235 is noted. © 1969 The American Physical Society.