Motion of charged particles in a stochastic magnetic field with a collisional noise

The diffusion of charged particles in a gaussian stochastic magnetic field characterized by finite correlation lengths λI and λ[formula] and gaussian coloured collisions with a finite correlation time τc is studied through the method of expansion with respect to a parameter ε which is introduced to denote the order of smallness. The mean square displacement in the perpendicular direction, Γ(t), is derived to the order of ε2. Several limiting cases are discussed and shown to recover the previous results. To the order of α5 [formula], the result is the same as that of Balescu, Misguich and Nakach, which was obtained after " Corrsin approximation It proves that the " =Corrsin approximation" is also reasonable in the short time regime.Wang Haida, Balescu Radu. Motion of charged particles in a stochastic magnetic field with a collisional noise. In: Bulletin de la Classe des sciences, tome 4, n°7-12, 1993. pp. 217-240