Simplification of the Boltzmann collision integral

摘要: Close collision events play an important role in situations where the Coulomb logarithm approaches unity. The five-fold Boltzmann integral takes into account close events. However, is generally considered too complex for practical use. In a previous paper [Y. Chang, Phys. Fluids B 4, 313 (1992)], with Maxwellian velocity distribution function field particles was reduced to three-fold kernel function. expressed form of infinite series. this brief communication, finite obtained and finally simple exactly.