Isotopic dependence of fusion cross-sections - linear relationships

A systematic study of isotopic dependence of fusion-cross-section is carrie d out by adding neutrons gradually to N=Z colliding nuclei. We find that fu sion barrier position increases and height decreases, both linearly with th e increase of N/Z ratio of the compound system. The increase in barrier pos ition is larger compared to decrease in barrier height. In terms of these l inear relationships, a parameterized form of fusion cross-sections is given for the neutron-rich colliding nuclei. The fusion cross-sections are also enhanced linearly with the N/Z ratio, and this enhancement is larger for lo wer incident centre-of-mass energies and independent of the choice of react ion partners. Experimental data and other theoretical studies are called fo r to verify these results.