Kinetic Theory of Strongly Magnetized Plasmas

Novel transport properties exhibited by plasmas that are strongly magnetized in the sense that the gyrofrequency exceeds the plasma frequency are not well understood. Here, we develop a generalized kinetic theory that can treat Coulomb collisions in plasmas across all magnetization strength regimes and which asymptotes to the traditional Boltzmann kinetic theory in the weakly magnetized limit. The theory also spans the weak to strong Coulomb coupling regimes by incorporating the mean force kinetic theory concept. To demonstrate the utility of the generalized theory, it is used to compute the friction force on a massive test charge moving through a strongly magnetized one-component plasma. Recent works studying weakly coupled plasmas have shown that strong magnetization leads to a transverse component of the friction force that is perpendicular to both the Lorentz force and velocity of the test charge; in addition to the stopping power component. Recent molecular dynamics simulations have also shown that strong Coulomb coupling in addition to strong magnetization gives rise to a third ``gyrofriction'' component of the friction force in the direction of the Lorentz force. Here, we show that the theory captures these effects and agrees well with the molecular dynamics simulations over a broad range of Coulomb coupling and magnetization strengths. The transverse force is found to strongly influence the average motion of a test charge by changing the gyroradius and the gyrofriction force is found to slightly change the gyrofrequncy of the test charge resulting in a phase shift.