The production cross sections for the actinides from ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$ bombardments of ${}_{}{}^{249}{}_{}{}^{}\mathrm{Cf}$ at energies 1.02, 1.09, and 1.16 times the Coulomb barrier were determined. Chemical fractions of the individual actinide elements were prepared and the gamma, alpha, and spontaneous fission activities of the actinide isotopes were measured. The cross section distributions are presented and compared with those from other heavy ion bombardments of actinide targets. Conclusions are drawn as to the utility of these heavy ion bombardments for producing unknown isotopes in the actinide region. It is shown that for new neutron-rich actinide isotopes with atomic numbers smaller than that of the target these very heavy ion bombardments are perhaps the best method of production, and when using the most neutron-rich targets available new neutron-rich isotopes should be produced in quantities sufficient for their identification and study.

• Received 12 February 1987

DOI:https://doi.org/10.1103/PhysRevC.35.2117