Kinetic theory of rf current drive and helicity injection

Technical Report · Thu Jul 11 04:00:00 EDT 1991

OSTI ID:5306348

Mett, R R

Current drive and helicity injection by plasma waves are examined with the use of kinetic theory. The Vlasov equation yields a general current drive formula which contains resonant and nonresonant contributions. Standard quasilinear current drive is described by the former, while helicity current drive may be contained in the latter. Since direct analytical comparison of the sizes of the two terms is in general difficult, a new approach is taken. Solution of the drift-kinetic equation shows that the standard Landau damping/transit time magnetic pumping quasilinear diffusion coefficient is the only contribution to steady-state current drive to leading order in {var epsilon}={rho}{sub L}/{sup l}, where {rho}{sub L} is the Larmor radius and l is the inhomogeneity scale length. All nonresonant contributions, including the helicity, appear at higher order, after averages are taken over a flux surface, over azimuth, and over time. Consequently, at wave frequencies well below the electron cyclotron frequency, a wave helicity flux perpendicular to the magnetic field does not influence the parallel motion of electrons to leading order and therefore will not drive a significant current. Any current associated with a wave helicity flux is then either ion current or electron current stemming from effects not included in the drift-kinetic treatment, such as cyclotron, collisional, or nonlinear. 20 refs.

• Research Organization: Texas Univ., Austin, TX (United States). Inst. for Fusion Studies
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG05-80ET53088
• OSTI ID: 5306348
• Report Number(s): DOE/ET/53088-508; IFSR--508; ON: DE91017388
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700103* -- Fusion Energy-- Plasma Research-- Kinetics
BEAM INJECTION
BOLTZMANN-VLASOV EQUATION
COLLISIONLESS PLASMA
DAMPING
DIFFERENTIAL EQUATIONS
EQUATIONS
HELICITY
KINETIC EQUATIONS
LANDAU DAMPING
NON-INDUCTIVE CURRENT DRIVE
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE PROPERTIES
PLASMA
PLASMA WAVES
RF SYSTEMS