Stochastic ion heating by a lower hybrid wave. II
The motion of an ion in a coherent lower hybrid wave (characterized by vertical bar/sub parallel/vertical bar much less than vertical bar kappa/sub perpendicular to/vertical bar and ..omega.. much greater than ..cap omega../sub i/) in a tokamak plasma is studied. For ions satisfying ..nu../sub perpendicular to/ > ..omega../kappa/sub perpendicular to/, the Lorentz force law for the ions is reduced to a set of difference equations which give the Larmor radius and phase of an ion on one cyclotron orbit in terms of these quantities a cyclotron period earlier. From these difference equations an earlier result (Phys. Fluids 21, 1584(1978)) that above a certain wave amplitude the ion motion is stochastic, is readily obtained. The stochasticity threshold is given a simple physical interpretation. In addition, the difference equations are used to derive a diffusion equation governing the heating of the ions above the stochasticity threshold. By including the effects of collisions, the heating rate for the bulk ions is obtained.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- DOE Contract Number:
- EY-76-C-02-3073
- OSTI ID:
- 6159903
- Report Number(s):
- PPPL-1528; TRN: 79-011927
- Country of Publication:
- United States
- Language:
- English
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HIGH-FREQUENCY HEATING
HYBRID RESONANCE
TOKAMAK DEVICES
FINITE DIFFERENCE METHOD
ION DRIFT
ION TEMPERATURE
LARMOR RADIUS
PLASMA WAVES
STOCHASTIC PROCESSES
CLOSED PLASMA DEVICES
HEATING
ITERATIVE METHODS
NUMERICAL SOLUTION
PLASMA HEATING
RESONANCE
THERMONUCLEAR DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
& Production