Electron cyclotron resonance heating on the TCA tokamak
Electron cyclotron resonance heating experiments at 39 GHz and power levels similar to ohmic heating power levels were conducted in the TCA tokamak, in either X- or O-mode. ECRH was observed to be more efficiently absorbed for low density and low q(a) discharges. At low density the central electron temperature was increased by a factor of two over ohmic cases and the stored energy increased by 40 % with up to 80 % of the plasma energy supplied by ECRH. During ECRH low density operation the electron energy confinement time tau(Ee) was the same as during pure ohmic heating but tau(Ee) degraded with ECRH power at high density. The decrease in the loop voltage required to maintain a constant current during ECRH is a very reproducible quantity and can be attributed in almost all cases to the change in the electron temperature. Sawtooth stabilisation was produced with a sawtooth period of up to 10 times greater than that before ECRH. This stabilization depended on the ECRH toroidal injection angle and total input power. High energy ions were observed and their production attributed to a 3-wave interaction process.
Bibliographic Reference: Report: LRP 459/92 EN (1992) 36 pp.
Availability: Available from Confédération Suisse, Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, 21 avenue des Bains, 1007 Lausanne (CH)
Record Number: 199310045 / Last updated on: 1994-11-29
Original language: en
Available languages: en