Further Measurements of Gamma Transitions in Spontaneous-Fission Fragments ofCf252

Abstract

$\ensuremath{\gamma}$ rays in the range from 150 to 1000 keV, following the spontaneous fission of $^{252}\mathrm{Cf}$, are observed with a 20-${\mathrm{cm}}^{3}$ Ge(Li) detector [full width at half maximum (FWHM) 3.5 keV at 356 keV] in coincidence with $K$ x rays from the fission fragments, observed with a 0.14-${\mathrm{cm}}^{3}$ Ge(Li) detector (FWHM 350 eV at 31 keV). Twenty-one 1024-channel $\ensuremath{\gamma}$-ray spectra were accumulated and sorted by computer, corresponding to windows set on $K$ x rays from Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Sb, Te, I, Xe, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, and Eu. In conjunction with previous work, this data allowed both mass and charge assignments to be made for about 90 of the observed transitions. Relative yields for certain $\ensuremath{\gamma}$ rays in self-gated spectra, those for which both x ray and $\ensuremath{\gamma}$ ray originated from the same isotope, have been measured and compared with predictions based on previous work.