HARD PHOTON-EMISSION IN HEAVY-ION REACTIONS

A number of recent experiments reveal the emission of hard photons in heavy-ion interactions. Assuming that these photons originate in single proton-neutron bremsstrahlung processes that add incoherently, their spectra are satisfactorily reproduced, at incident energies up to 70 MeV/nucleon, in both the case of asymmetric and symmetric systems, by calculations based on a system of master equations. The cross section for the elementary np np process is that, recently proposed by Nakayama and Bertsch, which includes convection, magnetic and exchange contributions. The initial energy distribution of the excited particles and holes is assumed to be that corresponding to two shifted Fermi spheres in momentum space. © 1990 The American Physical Society.