Particle heating by a low-amplitude wave in an inhomogeneous magnetoplasma

The phase-space diffusion of particles interacting with a monochromatic wave propagating at an arbitrary angle to an external inhomogeneous magnetic field is examined. It is shown that particle heating in an inhomogeneous plasma occurs at substantially smaller wave amplitudes than that characterizing the stochasticity threshold for a homogeneous plasma. The diffusion-coefficient dependence on the inhomogeneity parameter, wave amplitude, and wave propagation angle was investigated both analytically and by computer simulation. The property of periodicity in the relatioship between the diffusion coefficient and the inhomogeneity parameter is noted.