Effect of high order magnetic field harmonics on trapped particle confinement in torsatrons and heliotrons

摘要

Charged particle confinement in torsatrons and heliotrons is investigated with account taken of distant, high order magnetic field harmonics. Analytical estimations of the high order harmonics effect on confinement of both the passing and the trapped helical banana trajectories are obtained using bounce averaged equations of particle motion. These estimations are compared with the results of numerical integration of the guiding centre equations of particle motion in magnetic co-ordinates for heliotron/torsatron configurations of pre-reactor and reactor size, such as the Large Helical Device (LHD) and the Force-Free Helical Reactor (FFHR).