Samenvatting
High fusion performance has been achieved in optimized shear discharges
in JET with the early appearance of internal transport barriers (ITBs)
in the high power phase in both DD and DT plasmas. An ITB has been
produced in a large variety of conditions, including LHCD only, ICRH
only, NBI only and NBI + ICRH with LHCD preheat. An ITB may coexist with
the edge barrier. The high pressure gradient produced by ICRH combined
with high power NBI heating starting in a low density plasma with q(0)
approx 1.5-2 is the main prerequisite for an efficient ITB in high
performance discharges. Strong coupling between q profiles, MHD
activity, energy confinement and fusion yield has been observed. The
transition from L to H mode can be triggered by MHD events. The
transition is accompanied by significant momentary changes in the
density fluctuation spectrum in the peripheral plasma. The ITB may
persist for some time in both ELM-free and ELMy H mode.
Originele taal-2 | Engels |
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Pagina's (van-tot) | 1463-1480 |
Tijdschrift | Nuclear Fusion |
Volume | 39 |
Nummer van het tijdschrift | 10 |
DOI's | |
Status | Gepubliceerd - 1 okt. 1999 |
Extern gepubliceerd | Ja |