We have explored the viability of incoherent npγ bremsstrahlung as the dominant mechanism for the production of high energy γ rays in heavy-ion collisions by comparing the calculated relative angular distributions with experimental results. We have utilized the Boltzmann master equation model of heavy-ion collisions to decompose the reaction into first- and higher-order collision components in the assumed nucleon-nucleon cascade of the relaxation process. Within this decomposition we treat the γ-ray angular distribution of the first collision component by adopting a semiclassical npγ bremsstrahlung formula. The multiple collision component is assumed to contribute isotropically in the nucleus-nucleus center-of-mass system, and the Boltzmann master equation model enables us to weight these two components relative to one another. We then compare the predictions of our model with the available experimental results, finding generally favorable agreement between model and data. Within the uncertainties of our calculation and the data, the predicted angular distributions are consistent with an incoherent npγ bremsstrahlung mechanism as the source of high energy γ rays in intermediate energy heavy-ion collisions.

• Received 12 June 1987

DOI:https://doi.org/10.1103/PhysRevC.36.1387