Ion-cyclotron resonance heating by means of the fast wave in a longitudinally inhomogeneous magnetic field

Journal Article · Sat Jun 01 00:00:00 EDT 1985 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.864922· OSTI ID:5690270

Lashmore-Davies, C N; Fuchs, V; Cairns, R A

The coupling between the fast wave and the slow ion-cyclotron wave in a plasma in which the equilibrium magnetic field is longitudinally inhomogeneous is reconsidered, using a model studied by White, Yoshikawa, and Oberman (Phys. Fluids 25, 384 (1982)). Such a coupling can only occur when a second ion species is present and for finite k/sub perpendicular/. This configuration is of relevance to mirrors and also tokamaks. An approximate dispersion relation is obtained from the usual cold plasma model by replacing all slowly varying quantities by their value at the coupling point. The resulting equation preserves the cutoff properties of the original equation. The approximate dispersion relation is then used to analyze the mode conversion of the fast wave to the slow wave at the minority resonance. For N/sub perpendicular/equivalentc/sub A/k/sub perpendicular//..omega.. <<1 the transmission coefficient is close to unity but for N/sub perpendicular/ < or approx. =1 the transmission becomes very weak and for incidence from the stronger field region, the absorption becomes strong. When the wave is incident from the weaker field region the maximum absorption as a function of the minority fraction and N/sub perpendicular/ is 25%. Our results are obtained using second-order coupling theories, the advantages of which clearly emerge from this example.

• Research Organization: Euratom/UKAEA Fusion Association, UKAEA Culham Laboratory, Abingdon, Oxfordshire, OX14 3OB England
• OSTI ID: 5690270
• Journal Information: Phys. Fluids; (United States), Vol. 28:6
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COLD PLASMA
ENERGY ABSORPTION
ICR HEATING
CONVERSION
COUPLING
DISPERSION RELATIONS
MAGNETIC FIELDS
MAGNETIC MIRRORS
REFLECTION
TOKAMAK DEVICES
TRANSMISSION
ABSORPTION
CLOSED PLASMA DEVICES
HEATING
HIGH-FREQUENCY HEATING
OPEN PLASMA DEVICES
PLASMA
PLASMA HEATING
THERMONUCLEAR DEVICES
700101* - Fusion Energy- Plasma Research- Confinement
Heating
&amp; Production