RF HEATING ON JET
High power ICRF, P<or=7.2MW has been coupled to the JET plasma in a variety of conditions: outboard limiters, inner wall, combined operation with neutral beams and pellet injection. Long pulse modulation experiments (10s) yield a precise deposition profile which is extremely localized in agreement with expectations. The best heating efficiency is obtained when the minority resonance crosses the magnetic axis. With off-axis heating, the ion temperature broadens more than the electron temperature profile. A new operating regime, called "monster sawtooth' has been found during combined RF and NBI heating. The MHD quiet regime can last 1.26s and the central electron temperature rises to 7.4keV with a D->D reaction rate of 4x10**15s**-1. The temperature profile steepens over the entire profile and T-e is enhanced by a factor of 2.5 for combined power of 10 MW. RF heating of plasma fuelled with a single mildly penetrating pellet exhibits the normal L-mode behaviour. In combination with NBI, the input power reached 16 MW and the plasma stored energy reached 5.8MJ at the highest plasma current of 5MA. Recent experiments in single null X-point configuration with combined heating have shown the transition to an enhanced confinement regime (H-mode).
Bibliographic Reference: 11TH INTERNATIONAL CONFERENCE ON PLASMA PHYSICS AND CONTROLLED NUCLEAR FUSION RESEARCH, KYOTO (JAPAN), NOV. 13-20, 1986 WRITE TO THE PUBLICATIONS OFFICER, JET JOINT UNDERTAKING, ABINGDON, OXON OX14 3EA (UK), MENTIONING REPORT JET-P(86)44, 1986
Record Number: 1989125075500 / Last updated on: 1987-12-01
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