Ponderomotive Barrier as a Maxwell Demon
Authors: I.Y. Dodin, N.J. Fisch, and J.M. Rax
Date of PPPL Report: May 2004
Revised: July 2004
Published in: Phys. Plasmas 11:11 (November 2004) 5046-5064.
The possibility of efficient ponderomotive current drive in a magnetized plasma was reported recently [Phys. Rev. Lett. 91 (2003) 205004]. Precise limitations on the efficiency are now given through a comprehensive analytical and numerical study of single-particle dynamics under the action of a cyclotron-resonant radio-frequency drive in various field configurations. Expressions for the particle energy gain and acceleration along the dc magnetic field are obtained. The fundamental correlation between the two effects is described. A second fundamental quantity, namely the ratio of the potential barrier to the energy gain, can be changed by altering the field configuration. The asymmetric ponderomotive current drive effect can be optimized by minimizing the transverse heating.