EFFECTS OF THE ALFVEN WAVE SPECTRUM IN HEATING EXPERIMENTS IN TCA
Reduction of the metallic impurity concentration in the TCA plasma has enabled us to correlate the observed heating with the calculated position where the rf energy is deposited. In modelling the measured antenna loading due to the presence of Alfven resonance surfaces, and hence inferring the energy deposition profile, both ion cyclotron effects and the toroidal geometry must be considered. In particular, toroidicity couples energy to resonance surfaces that would not be excited in cylindrical geometry. The increase in electron density during a rf pulse changes the positions of these surfaces so that spectrum related effects may be observed. The appearance of a new surface at the centre of the plasma is seen as a sharp discontinuity on many of the macroscopic parameters, accompanied by evidence of changes in the current density profile. These results, and the predictions of numerical codes, have imposed new constraints on the optimisation of our antenna system.
Bibliographic Reference: 1984 INTERNATIONAL CONFERENCE ON PLASMA PHYSICS, CRPP-EPFL, LAUSANNE (SWITZERLAND), JUNE 27-JULY 3, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31699 ORA
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Record Number: 1989123011700 / Last updated on: 1987-01-01
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