The effect of sawteeth on fast ion confinement in JET during ICRHFunded under: FP3-FUSION 11C
It is possible that the loss of resonant ion confinement during the sawtooth crash may be due to fast radial diffusion driven by a kink type of instability within the plasma core. Starting from a simplified model of a helically distorted toroidal magnetic field, and assuming the ions to be confined to the q less than 1 region of the plasma, a diffusion coefficient is obtained. Assuming that the resonant ion tail formation and relaxation processes are classical, the time development of the fast ion energy content of the plasma is modelled. Finally, an estimate of the loss of fast ions from the plasma core during the crash is given for a typical JET ICRH discharge, and the fraction of ions ejected from the core is obtained by direct comparison with experimental data.
Bibliographic Reference: Report: JET-P(94)02 EN (1994) 15 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199410322 / Last updated on: 1994-11-28
Original language: en
Available languages: en