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Abstract
A bounce-averaged, mapping formalism is developed for single particle trajectories in a tokamak plasma confinement device with small toroidal magnetic field ripple. In particular, a bounce-averaged Monte Carlo collision operator is presented and investigated. Particle diffusion rates are derived analytically, elucidating and extending previous work. Where feasible, computer simulations are used to provide verification of the diffusion coefficients. A new resonance effect is uncovered with inverse scaling with collisionality, with implications for confinement and probably other physical systems described by the Taylor-Chirikov map with small extrinsic noise.
Particle and energy confinement are further explored for sensitivity to deviations from thermal equilibrium, for example due to the transport scaling mentioned above. The model of a truncated Maxwellian distribution is shown to give predictions for energy confinement that differ from the Maxwellian assumption, and are in good agreement with Monte Carlo simulation.
