High-concentration minority ion-cyclotron resonance heating in the JET tokamakFunded under: FP2-FUSION 10C
With a view to heating a 50/50 D-T reactor plasma, ion-cyclotron resonance heating (ICRH) at a power level of 10 MW has been demonstrated in the JET tokamak for minority hydrogen concentration approaching that of He3. In high minority ICRH experiments using (H)-He3 plasmas, improved bulk-ion heating has been observed as the minority-ion tail temperature was lowered to a level below the critical energy so that the tail gave more than 50% of its power to the bulk ions. When the ratio of the total input power to the central electron density is of the order of 2.3 x 1.0 E-19 MW/m3, electron and ion temperature values around 7 keV have been obtained in limiter L-mode discharges where the global energy confinement is similar to that found in other ICRH L-mode discharges. The results of observed tail temperature, fast-ion energy and minority density are well understood in terms of minority ICRH physics and the Stix theory. Further, it has been shown theoretically that when the wave is launched by an antenna in (0,pi)-phasing from the low-field side in large and hot reactor-like plasmas, strong single-pass damping can be maintained at minority concentrations approaching that of majority and the occurrence of ion-ion hybrid mode conversion-cutoff layers would be of no consequence, since most of the wave power is absorbed before it reaches this region.
Bibliographic Reference: Report: JET-P(92)49 EN (1992) 29 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199211273 / Last updated on: 1994-11-29
Original language: en
Available languages: en