Collisions in magnetised plasmas

Abstract

Abstract. Approximations for closing the kinetic equation for the one particle distribution function are calculated by using propagators. These provide the formal structure of the collision term in the Landau approximation. The method allows one to investigate the effect of inhomogeneities at the Debye scale and to analyse magnetised collisions, when the Larmor radius is smaller than the Debye length. This method also allows one developing a simple renormalisation scheme to derive the Lenard-Balescu collision operator.

On the Turbulent Behavior of a Magnetically Confined Plasma near the X-Point

“…Now, the spatial scale of the turbulence runs from few millimeters to ten centimeters, a scale surely much greater than the plasma Debye length (justifying the quasi-neutrality assumption) and significantly greater than the Larmor radius of the ions (allowing to speak of low frequency dynamics). Furthermore, the mean free path of the plasma constituents is about one meters, i.e., two orders of magnitude smaller than the parallel connection length of the background magnetic field [21]. Thus, the plasma has a collisional nature and the two-fluid approximation is appropriate to describe the dynamics.…”