Nonadiabatic Particle Motion in a Magnetic Mirror

Abstract

The basic features of the nonadiabatic escape of charged particles from an axisymmetric mirror are studied by use of the equation of single particle motion. We obtain an expression for the change of the magnetic moment along a particle orbit in the mirror whose field strength varies sinusoidally in space. The theoretical values for the change are in good agreement with numerical results. The calculational results for the nonadiabatic escape are compared with the predictions of the existing theoretical model: “diffusion” model derived by B. V. Chirikov. The predictions agree well with our results outside the Störmer zone.