Inverse bremsstrahlung absorption in magnetized plasmas

Abstract

The Magneto-Inertial Fusion (MIF) approach has the benefits of both approaches of Inertial Confinement Fusion (ICF) and Magnetic Confinement Fusion (MCF). MIF is a complete approach, as compared to others. It has the advancement of the common ICF and some advantages over MCF. It also includes high-density plasma in the presence of strong magnetic fields. In this study, we investigate the inverse bremsstrahlung absorption (IBA) in magnetized plasma and the kinetic theory. Many researchers have calculated the inverse bremsstrahlung absorption coefficient through the ICF approach. In this investigation, however, the average of IBA is obtained that can be used in the MIF approach, the kinetic theory and the Krook collision frequency. In addition, the influences of some parameters such as laser wavelength, electron temperature, and static magnetic field are shown on the mean collisional absorption. A numerical solution is also used to calculate the dispersion function and the laser electric field. IBA is one of the basic heating processes in laser fusion plasma. The results of the study show that, in critical layers, the increase of absorption is proportional to short laser wavelength, low electron temperature, but IBA varies slowly with the static magnetic field.