FINITE LARMOR RADIUS APPROXIMATION FOR COLLISIONAL MAGNETIC CONFINEMENT. PART I: THE LINEAR BOLTZMANN EQUATION

The subject matter of this paper concerns the derivation of the finite Larmor radius approximation, when collisions are taken into account. Several studies are performed, corresponding to different collision kernels : the relaxation and the Fokker-Planck operators. Gyroaveraging the relaxation operator leads to a position-velocity integral operator, whereas gyroaveraging the linear Fokker-Planck operator leads to diffusion in velocity but also with respect to the perpendicular position coordinates.