FINITE LARMOR RADIUS EFFECTS ON ALFVEN-WAVE CURRENT DRIVE IN LOW-ASPECT-RATIO TOKAMAKS

Alfven wave current drive (AWCD) in low-aspect ratio (A = R/a = 1/epsi lon greater than or similar to 1) tokamaks (LARTs) is studied numerica lly. For this, the full-wave equation (E-parallel to not equal 0) with a Vlasov-based dielectric tensor is solved by relaxation techniques, subject to appropriate boundary conditions at the plasma centre and at the plasma-vacuum interface, as well as the concentric antenna curren t sheet and at the external metallic wall. A systematic investigation of the physical characteristics of the AWCD generated in LARTs when ki netic effects are considered is carried out and illustrative results a re presented and discussed.