Nuclear medium effects on pre-equilibrium nucleon- emission reactions

Nuclear medium modifies the free nucleon-nucleon interaction cross section. The modified value of the cross section has its own impact on the preequilibrium emission spectrum. Such effect increases or decreases the tendency on neutron emission in comparative with proton emission. Several model of the in-medium nucleon-nucleon interaction cross sections are used in the calculation of the neutron emission spectra for some proton induced reactions. Results showed that as the mass of the target nucleus increases, the nuclear medium produces lesser influence than it does for smaller mass nuclei.