Onset and Saturation of Ion Heating by Odd-parity Rotating-magnetic-fields in a Field-reversed Configuration
Authors: A.S. Landsman, S.A. Cohen, and A.H. Glasser
Date of PPPL Report: November 2005
Published in: Physical Review Letters 96, 015002 (Jan 2006) 4pp
Presented at the Forty-Seventh Annual Meeting of the APS Division of Plasma Physics, 24 - 28 October 2005, Denver, Colorado
Heating of figure-8 ions by odd-parity rotating magnetic fields (RMFο) applied to an elongated field-reversed configuration (FRC) is investigated. The largest energy gain occurs at resonances (s ≡ ωR⁄ω) of the RMFο frequency, ωR, with the figure-8 orbital frequency, ω, and is proportional to s2 for s – even resonances and to s for s – odd resonances. The threshold for the transition from regular to stochastic orbits explains both the onset and saturation of heating. The FRC magnetic geometry lowers the threshold for heating below that in the tokamak by an order of magnitude.