On the nuclear charge and atomic mass of attenuated mean fission fragments

Abstract

The changes in the nuclear charge and in the atomic mass values of 235U and 252Cf mean fission fragments during their attenuation in matter have been analyzed. It is shown that the greatest changes occur for 252Cf fission fragments in light stopping materials. After an energy loss of 55 MeV in nitrogen a change of one unit in the nuclear charge value of the mean heavy 252Cf fission fragment was found. Such deviations cause corrections of up to 5% in the stopping power of the mean light fission fragment and up to 3% in the mean heavy fission fragment. A direct comparison of the measured stopping power of Xe projectiles and of mean heavy fission fragments in solids and in gases shows that the two sets of data are consistent.