Excitation functions for production of heavy actinides from interactions ofO18withCm248andCf249

Abstract

Excitation functions have been measured for the production of isotopes of Bk through Fm in bombardments of $^{248}\mathrm{Cm}$ with 97- to 122-MeV $^{18}\mathrm{O}$ ions and of isotopes of Bk through No in bombardments of $^{249}\mathrm{Cf}$ with 91- to 150-MeV $^{18}\mathrm{O}$ ions. The cross sections and widths of the mass distributions for the actinides produced in these reactions are very similar for transfer of the same numbers of nucleons. A semiquantitative comparison of the experimental results with calculations based on a simple model shows that calculations of this type are helpful in selection of projectile-target systems and optimum energies for production of specific actinide isotopes and for synthesis of as yet unknown heavy isotopes and elements. Comparisons of experimental results with calculations show that, in general, about half of the kinetic energy of the projectile is transferred to the actinide product.NUCLEAR REACTIONS $^{248}\mathrm{Cm}(^{18}\mathrm{O}, X)$, $E(^{18}\mathrm{O})=97, 104, 113, 122$ MeV; $^{249}\mathrm{Cf}(^{18}\mathrm{O}, X)$, $E(^{18}\mathrm{O})=91, 97, 104, 113, 122, 150$ MeV; measured $\ensuremath{\sigma}$ and isotopic distributions for $Z=97\ensuremath{-}102$.