PRODUCTION OF HAFNIUM NUCLIDES IN THE REACTIONS OF 6.3 TO 24.6-MEV NUCLEON AR-40 IONS WITH NATURAL TUNGSTEN/

The yields of known hafnium isotopes produced in the reactions of 6.3- to 24.6-MeV/nucleon Ar-40 ions with natural tungsten were determined by gamma ray spectroscopy following chemical separation. Excitation fu nctions, average forward ranges, and isotope distributions were obtain ed. It was deduced that using intermediate-energy heavy ions the synth eses of new neutron-rich isotopes in the region A > 170 is possible. U se of tick targets or a series of multi-thin targets could increase th e yields of new neutron-rich isotopes. Raising the projectile energy m ight not be helpful to synthesize such new neutron-rich isotopes due t o possible increased backgrounds from neutron-deficient isotopes.