LAUSR

The description of the dynamics of charged-particles in an inhomogeneous magnetic field is a fundamental problem in space plasma physics. Since, this dynamics has a character of a nonlinear oscillator, the traditionally used approaches involve certain limiting conditions regarding the scales of magnetic field, particle motion, and the assumptions about conservation of specific invariants (e.g., the magnetic momentum, integrals of action, etc.). Such approaches naturally restrict the detailization the considered particle dynamics which is described in terms of the integral characteristics and averaged parameters of motion. However, in some regions the precise account of the particle trajectory details and the motion features (e.g., the phase of gyration) are of crucial importance. In this paper, we present a method for the description of particle dynamics, based on a new system of differential equations for the particle pitch-angle θ and phase of rotation ϕ, which are derived from the analysis of the parti...