PPPL-3514 is available in pdf or postscript formats.

Generation of Plasma Rotation in a Tokamak by Ion-Cyclotron Absorption of Fast Alfvén Waves

Authors: F.W. Perkins, R.B. White, P.T. Bonoli, and V.S. Chan

Date of PPPL Report: November 2000

Presented at: the 18th International Atomic Energy Agency's (IAEA) Fusion Energy Conference 2000 (FEC-2000) held in Sorrento, Italy, October 4-10, 2000. An unedited proceedings will be published by IAEA in electronic format (CD-ROM) only.

A mechanism is proposed and evaluated for driving rotation in tokamak plasmas by minority ion-cyclotron heating, even though this process introduces negligible angular momentum. The mechanism has two elements: First, angular momentum transport is governed by a diffusion equation with a non-slip boundary condition at the sepatratrix. Second, Monte-Carlo calculations show that energized particles will provide a torque density source which has a zero volume integral but separated positive and negative regions. With such a source, a solution of the diffusion equation predicts the on-axis rotation frequency W to be W = (4q max W J * ) (eBR3a2ne(2p)2)-1(tM/tE) where | J * | approximatelty equal to 5-10 is a nondimensional rotation frequency calculated by the Monte-Carlo ORBIT code. Overall, agreement with experiment is good, when the resonance is on the low-field-side of the magnetic axis. The rotation becomes more counter-current and reverses sign on the high field side for a no-slip boundary. The velocity shear layer position is controllable and of sufficient magnitude to affect microinstabilities.