Systematics of production cross sections in Cr54 -induced fusion evaporation reactions

A series of fusion evaporation reactions induced by the ⁵⁴Cr¹⁷⁺ beam have been performed using the gas-filled recoil separator SHANS2. The excitation functions of ⁵⁴Cr+¹⁵⁹Tb and ⁵⁴Cr+¹⁶⁵Ho reactions were measured. The systematics of cross sections for reactions with ⁴⁰Ar, ⁴⁸Ca, ⁵⁰Ti, and ⁵⁴Cr projectiles are compiled and discussed. It is suggested that employing the ⁵⁴Cr beam holds the potential for synthesizing neutron-deficient actinide nuclei. In addition, we attempted to synthesize undiscovered americium isotopes with ¹⁷⁵Lu(⁵⁴Cr,3n--4n)225,226Am reactions. No events were observed originating from ²²⁵Am and ²²⁶Am, and the upper limits were estimated to be 2.1 and 1.7 pb, respectively. The significantly low fission barrier of the com- pound nucleus ²²⁹Am, which leads to the small survival probability, might be a possible reason for the low cross sections.