POWER ABSORPTION STUDIES FOR LOWER HYBRID HEATING AND CURRENT DRIVE IN ASDEX
The absorption of Lower Hybrid waves has been investigated on ASDEX in the density range 2 x 10**12 cm**3 - 4 x 10**13 cm**-3. For most of the experiments the radiated rf power exceeded largely the Ohmic power input. The parallel refractive index N,, was altered between 4 and nearly 1. Heating and current drive, respectively, were studied with stationary or propagating waves. Several figures of merit may be used for the different schemes of Lower Hybrid application: A current drive efficiency for stationary rf current drive, a recharging efficiency for power transfer into the primary circuit of the OH transformer by an rf driven current and a heating efficiency for the increase of the central plasma energy density by rf heating. In order to obtain a more general criterion which applies to all modes of LH operation a total absorption coefficient of rf power from the global power balance at the begin of the rf pulse was derived. Using this absorption coefficient, the energy confinement time is then determined during the stationary phase.
Bibliographic Reference: 12TH EUROPEAN CONFERENCE ON CONTROLLED FUSION AND PLASMA PHYSICS, BUDAPEST (HUNGARY), SEPT. 2-6, 1985 WRITE TO MAX-PLANCK-INSTITUT FUER PLASMAPHYSIK, 8046 GARCHING BEI MUENCHEN (GERMANY), MENTIONING REPORT IPP III/107, 1985, PP. 77-80.
Record Number: 1989124096200 / Last updated on: 1987-01-01
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