Quasilinear space-dependent diffusion in the lower hybrid waves regime
The quasilinear diffusion coefficient for the inherently space-dependent diffusion in lower hybrid heating and current drive experiments is derived; it concludes with the usual space-independent approximation where the RF field amplitude is almost constant. The form of the distribution function in the `plateau' region and for large velocities (where the quasilinear diffusion coefficient seems to lead to unphysical results) is obtained. The position and width of the `plateau' (which are essential quantities in the theoretical description of LH experiments) are derived and their dependence on the RF field amplitude gradient is stressed. Finally, the ponderomotive effect (which plays a substantial role in LH experiments by causing large gradients of the electrostatic field amplitude) is derived, allowance being made for distortions of the distribution from Maxwellian.
Bibliographic Reference: Report: IPP6/284 EN (1989)
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199010710 / Last updated on: 1994-12-01
Original language: en
Available languages: en