Coulomb focusing and quantum effects on the electron-ion bremsstrahlung processes in plasmas

Abstract

The electron-ion bremsstrahlung process in a kappa-Maxwellian distribution plasma is investigated. The Coulomb correction effect on the bremsstrahlung emission rate from the kappa-Maxwellian distribution plasma is investigated as a function of the radiation photon energy for T ʈ ϾT Ќ , T ʈ ϭT Ќ , and T ʈ ϽT Ќ , where T ʈ and T Ќ are the parallel and perpendicular temperatures, respectively. The results show that for low photon energies the Coulomb focusing effects are found to be less significant for low spectral indices when T ʈ ϽT Ќ . However, for high photon energies, the Coulomb correction effects are found to be almost identical for all spectral indices. It is also found that the Coulomb focusing effects for T ʈ ϾT Ќ are more significant than those for T ʈ ϽT Ќ . In addition, the plasma screening and quantum effects on the nonrelativistic electron-ion bremsstrahlung process in strongly coupled semiclassical plasmas are also investigated using the effective screened potential model taking into account the plasma screening effect, as well as the quantum-mechanical effect. The analytic form of the bremsstrahlung radiation cross section in strongly coupled semiclassical plasmas is obtained as a function of the radiation photon energy, electron kinetic energy, thermal de Broglie wavelength, and Debye length. It is found that the quantum effect on the bremsstrahlung radiation cross section is slightly increased with increasing radiation photon energy. The quantum effect on the bremsstrahlung cross section is also found to be more important than the plasma screening effect on the bremsstrahlung process in strongly coupled semiclassical plasmas.