Kinetic equilibria of plasma shear layers

The analysis of plasma beam and shear problems in magnetic fields is usually based on a hydromagnetic fluid model. In a low-density collisionless plasma, however, the kinetic effects of the plasma, such as finite Larmor radius effects, are not yet clearly understood. In this paper, the kinetic equilibria of plasma shears in a uniform and fixed magnetic field, with full ion motion, are discussed by solving the Vlasov equation with a given electric field and drift velocity. In this model, the ion density profile through the plasma shear layer is quite different from the one predicted by a hydromagnetic model. As a result of a complicated ion gyromotion through the shear layer, single- and double-humped ion density profiles are obtained. The dependence on the temperature and the strength of the shear will be discussed. The results show a significant difference between positive and negative shears.