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 with54,56Fe,58Ni and59Co targets in the bombarding energy range 14–27 MeV. The cross-section-weighted average charge\(\overline {\Delta Z}\) and mass\(\overline {\Delta A}\) removed from the compound system were deduced and compared with results reported for heavy-ion induced reactions. Variation of\(\overline {\Delta A}\) 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 forA≈60 nuclei. The average evaporated charge\(\overline {\Delta Z}\) depends on both the CN excitation energy E CN * and the compound nucleusN andZ numbers. The\(\overline {\Delta A}\) and\(\overline {\Delta Z}\) dependence on excitation energy and the projectile-target combination can be understood in terms of the statistical model calculations.