Mass and charge release by the evaporation of particles from compound nuclei around mass 60

Reaction product cross sections have been measured for reactions of⁴He projectile with^54,56Fe,⁵⁸Ni and⁵⁹Co targets in the bombarding energy range 14–27 MeV. The cross-section-weighted average charge and mass removed from the compound system were deduced and compared with results reported for heavy-ion induced reactions. Variation of with E_CN^* is independent of the initial angular momentum of compound nucleus in theA=60 mass region in contrary to the rare-earth region. This would suggest a strong angular momentum removal from the compound nucleus by evaporation of particles forA60 nuclei. The average evaporated charge depends on both the CN excitation energy E_CN^* and the compound nucleusN andZ numbers. The and dependence on excitation energy and the projectile-target combination can be understood in terms of the statistical model calculations.We would like to acknowledge the interest and support of this work by Prof. A. Budzanowski. We wish to express our gratitude to Dr. E. Rurarz for his help with preparing the scattering chamber and Faraday cup used in this work. This work was supported by the Polish Government Central Research Program Grant CPBP 01.09 and the Polish Ministry of Education Grant G-MEN-207/90.