The role of RF in the optimized shear scenario on JET

Journal Article · Mon Sep 20 04:00:00 EDT 1999 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.59749· OSTI ID:21210467

Soeldner, F X; Alper, B; Baranov, Yu F; Bickley, A; Challis, C D; Conway, G; Cottrell, G A; Benedetti, M de; Deliyanakis, N; Erents, K; Gormezano, C; Gowers, C; Jones, T T. C.; Lomas, P J; Maas, A; Mailloux, J; Parail, V V; Rimini, F; Sips, A C. C.; Smeulders, P ^[1]

---

1. JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom)

RF heating and current drive with ion cyclotron waves and Lower Hybrid waves have been crucial for the development of the Optimized Shear scenario on JET to high performance. Peaked electron temperature profiles and improved energy confinement could be obtained with electron heating both from LHCD and ICRH during plasma current ramp up. ICRH and NBI comparisons allow to separate heating and fueling and suggest a dominant role of core heating in the formation of an Internal Transport Barrier (ITB). ICRH and NBI powers are there equivalent. Pressure profile control by varying the composition of centrally peaked ICRF and broader NBI deposition improves MHD stability. Current profile modifications in a wide range have been obtained with LHCD and in combination with NBI during current ramp up. During the high performance phase, however, LH coupling degrades strongly due to the steep edge density gradient resulting in a drop of the density in front of the LH antenna to the cut-off density. High fusion performance achieving simultaneously high beta values and bootstrap currents is predicted in scenario modeling using pressure and current profile control with ICRF and LHCD.

• OSTI ID: 21210467
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 485; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANTENNAS
BOOTSTRAP CURRENT
CHARGED-PARTICLE TRANSPORT
COMPARATIVE EVALUATIONS
COUPLING
ELECTRON TEMPERATURE
ELECTRONS
HIGH-BETA PLASMA
ICR HEATING
ION PLASMA WAVES
ION TEMPERATURE
LOWER HYBRID CURRENT DRIVE
LOWER HYBRID HEATING
MAGNETOHYDRODYNAMICS
PLASMA INSTABILITY
PLASMA PRESSURE
RF SYSTEMS
SHEAR
THERMAL BARRIERS