KX Rays fromCf252Fission Fragments in Ternary Fission

Abstract

The yield and the energy distribution of the $K$ x rays emitted by ${\mathrm{Cf}}^{252}$ fission fragments have been simultaneously measured for the cases of ternary and binary fission, with a cooled lithium-drifted silicon detector. The $K$ x-ray yields in ternary fission are found to be greater than in binary fission by (25\ifmmode\pm\else\textpm\fi{}6) and (14\ifmmode\pm\else\textpm\fi{}6)% for fragments in the light and the heavy groups, respectively. It has been shown that a comparison of $K$ x-ray yields and the energy spectra in binary and ternary fission can give information about the origin of the light charged particles emitted in ternary fission. From the analysis of the present results, it is inferred that these charged particles do not originate at the expense of nucleons exclusively from either of the fragment groups, but are liberated from the fissioning nucleus as a whole, implying emission just before or at the instant of scission.