ICRF heating and synergistic LH and fast-wave current drive in JETFunded under: FP2-FUSION 10C
Ion cyclotron resonance heating (ICRH) experiments in JET have been carried out in a variety of scenarios using advanced antennae, phasing and matching techniques leading to improved plasma performances. A record ICRH power of 22 MW has been coupled to the plasma in L-mode. Also, about 3 MW has been coupled for as long as 1 minute with little change in Z(eff). ICRH produced H-modes have a duration of 2.8 s at power levels of about 12 MW. Pellet produced peaked-density profiles reheated with ICRH have been combined with H-modes to produce T(i0) greater than or equal to T(e0) and highest thermonuclear yield where the thermal triple fusion product value close to 7.8 x 1.0 E20/m3.s.keV has been achieved. Good confinement and ion heating have been demonstrated both in the two-minority scheme and in the high-minority heating scenario (H-minority in He3-plasmas). Unidirectional superthermal electrons produced by a lower-hybrid current drive (LHCD) system have been synergistically accelerated by transit-time magnetic pumping (TTMP) of fast waves coupled by ICRH in the (0,0)-phasing of the antenna. This produces TTMP current drive even without phasing the ICRH antennae. Finally, in the minority current-drive scenario which is predicted to control the shear (dq/dr), marked differences in the sawteeth behaviour have been observed in experiments when the phase of the antennae was reversed while depositing power near the q = 1 surface.
Bibliographic Reference: Report: JET-P(91)44 EN (1991) 15 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199210161 / Last updated on: 1994-12-02
Original language: en
Available languages: en