Current production by cyclotron heating of electrons passing through an axial magnetic field gradient

• Published in: Nuclear fusion Vol. 21; no. 9; pp. 1207 - 1212
• Main Authors: Parks, P.B, Marcus, F.B
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.09.1981
• ISSN: 0029-5515; 1741-4326
• DOI: 10.1088/0029-5515/21/9/005

Consideration is given to a scheme for the production of a steady-state current in a toroidal plasma by the cyclotron heating of electrons in the region of a localized axial magnetic field gradient. In this scheme, the circulating electrons encounter simultaneously a magnetic mirror force due to the field gradient and cyclotron resonance wave causing a kick in electron perpendicular velocity and magnetic moment, leading to a systematic increase in electron parallel momentum. Calculations show that the current produced in this manner is largest when the magnetic gradient is localized over a small fraction of the torus. It is also demonstrated that the current produced by the magnetic gradient effect is comparable to that induced by the anisotropic heating effect considered by Fisch and Boozer (1980).