On RF heating of inhomogeneous collisional plasma under ion-cyclotron resonance conditions
- Kurchatov Institute (Russian Federation)
During ion-cyclotron resonance (ICR) heating of plasma by the magnetic beach method, as well as in some other versions of ICR heating, it is necessary to excite Alfvén oscillations. In this case, it is difficult to avoid the phenomenon of the Alfvén resonance, in which Alfvén oscillations transform into lower hybrid oscillations. The latter efficiently interact with electrons, due to which most of the deposited RF energy is spent on electron (rather than ion) heating. The Alfvén resonance takes place due to plasma inhomogeneity across the external magnetic field. Therefore, it could be expected that variations in the plasma density profile would substantially affect the efficiency of the interaction of RF fields with charged particles. However, the results obtained for different plasma density profiles proved to be nearly the same. In the present work, a plasma is considered the parameters of which correspond to those planned in future ICR plasma heating experiments on the PS-1 facility at the Kurchatov Institute. When analyzing the interaction of RF fields with charged particles, both the collisionless resonance interaction and the interaction caused by Coulomb collisions are taken into account, because, in those experiments, the Coulomb collision frequency will be comparable with the frequency of the heating field. Antennas used for ICR heating excite RF oscillations with a wide spectrum of wavenumbers along the magnetic field. After averaging over the spectrum, the absorbed RF energy calculated with allowance for collisions turns out to be close to that absorbed in collisionless plasma, the energy fraction absorbed by electrons being substantially larger than that absorbed by ions.
- OSTI ID:
- 22472065
- Journal Information:
- Plasma Physics Reports, Vol. 41, Issue 11; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-780X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Self-consistent modeling of radio-frequency plasma generation in stellarators
Particle and wave dynamics in a magnetized plasma subject to high rf pressure
Related Subjects
ALFVEN WAVES
ANTENNAS
CHARGED PARTICLES
COLLISIONAL PLASMA
COLLISIONLESS PLASMA
COMPARATIVE EVALUATIONS
ELECTRONS
ICR HEATING
ION CYCLOTRON-RESONANCE
LOWER HYBRID CURRENT DRIVE
LOWER HYBRID HEATING
MAGNETIC FIELDS
OSCILLATIONS
PLASMA DENSITY
THERMONUCLEAR DEVICES