RESULTS OF RF HEATING ON JET AND FUTURE PROSPECTS
Ion Cyclotron Resonance Heating (ICRH) has been applied to various JET plasmas with net coupled powers reaching 7 MW for several seconds. Conditioning with helium discharges is shown to be effective in controlling the density and in reducing the total radiated power to about 25% of the input power. Onaxis heating invariably results in long sawteeth of large amplitude. In most high power cases, a sudden bifurcation to monster sawteeth as long as 1.6 s is observed. The monster sawtooth is accompanied by an improvement in energy confinement time (f520%) and by an increase in density. Central electron and ion temperatures of 7 and 5.5 keV respectively have been achieved with 6.5 MW of ICRF power. The heating rate is reduced with offaxis heating in agreement with diffusive heat transport models. The future RF programme on JET includes upgrading the ICRF power to 20 MW and the development of current drive methods using a phased ICRF array of 8 antennae and later on a Lower Hybrid Current Drive system at 3.7 GHz with a 10 MW launcher.
Bibliographic Reference: WRITE TO THE PUBLICATIONS OFFICER, JET JOINT UNDERTAKING, ABINGDON, OXON OX14 3EA (UK), MENTIONING REPORT JET-P(87)21, 1987
Record Number: 1989126004600 / Last updated on: 1988-02-01
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