ACCURATE TREATMENT OF COULOMB CONTRIBUTION IN NUCLEUS NUCLEUS BREMSSTRAHLUNG

Partial-wave expansions of nucleus-nucleus bremsstrahlung cross sections converge very slowly as a function of orbital momentum, especially at small deflection angles. While nuclear effects can easily be restricted to a limited number of partial waves, Coulomb effects contribute to much higher partial waves because of the long range of the force. We accurately solve this problem by separating the bremsstrahlung matrix element into a purely Coulomb part and a fast-converging series. The Coulomb contribution is calculated by numerically integrating analytical expressions of the Coulomb bremsstrahlung matrix element. The accuracy of the results and the importance of the corrections are studied in a potential-model description of the alpha(alpha, alpha-gamma)alpha reaction.