Effect of lower hybrid heating on fast ion behavior in a tokamak

Behavior of fast ions coupled with lower hybrid waves is investigated numerically in a tokamak geometry. Applying the stochastic ion heating theory proposed by Karney to a real geometry, it is confirmed that the ions are accelerated stochastically and form the high energy tail in 0.1-0.2 ms. As regards the particle confinement, it is clarified that the lower hybrid heating results in an enhancement of the ion orbit loss. The RF power and the plasma current dependence of the loss fraction is obtained. (author)