The phenomenon of nucleon emission at high angular momentum states of fused compound systems

摘要

Nucleon emission from high spin fused compound systems is analyzed in the framework of the statistical theory of hot rotating (STHR) nuclei. This is an elaborate version of our earlier work and we present our results for156Er,166Er,168 Yb and188Hg. We predict an increase in neutron emission for166Er due to the abrupt decrease in neutron separation energy aroundI ≈55ℏ. Since the drop in the separation energy is closely associated with the structural changes in the rotating nuclei, relative increase in neutron emission probability around certain values of angular momentum may be construed as evidence for the shape transition. A similar effect is predicted for168Yb aroundI ≈55ℏ. We also extend the microscopic cranked Nilsson method (CNM) to hot nuclear systems and compare the results with that of the STHR method. The two methods yield different results for triaxially deformed nuclei although for biaxial deformations the results are identical. This is illustrated for186Hg. Keywords Separation energy - nucleon emission - shape transition - structural changes PACS Nos 21.10.Ma - 24.60.-k - 27.70.+q