Published October 29, 2001 | Version v1
Journal article

Sawtooth and Neoclassical Tearing Mode seed island control by ICRF current drive on JET

  • 1. Euratom/UKAEA Fusion Association, Culham, Abingdon OXON OX14 3DB (United Kingdom)
  • 2. Association Euratom-Confederation Suisse, CRPP/EPFL, 1015 Lausanne (Switzerland)
  • 3. Association Euratom-CEA, CEA-Cadrache, 13108 Saint-Paul-Lez-Durance (France)
  • 4. Association Euratom-FOM, FOM-Rijnhuizen/TEC, PO Box 1207, 3430 BE Nieuwegein, Nederlands (Netherlands)
  • 5. Helsinki Univ. of Technology, Association Euratom-Tekes, P.O. Box 2200, FIN-02015 HUT (Finland)
  • 6. Euratom-VR Asossiation, Swedish Research Council, SE 10378 Stockholm (Sweden)
  • 7. EFDA-JET CSU, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

Description

In recent experiments at JET, ICRF waves were used to either stabilize or destabilize sawteeth, and consequently control the formation of the seed island responsible for the appearance of Neoclassical Tearing Modes (NTMs) known to limit the tokamak performance. Two scenarios were studied in deuterium plasmas with a hydrogen concentration of 5 to 10%. Firstly, using a toroidal magnetic field B0 of 2.5T, the fundamental hydrogen cyclotron resonance layer (ω=ωcH) was positioned at the High Field Side (HFS) at the sawtooth inversion radius (Rinv∼Rq=1). With +90 deg. phased wave, monster sawteeth were obtained that triggered NTMs. Secondly, ICRF waves at the 2nd harmonic hydrogen cyclotron resonance (ω=2ωcH) positioned at the Low Field Side (LFS) with B0 between 1.2 T and 1.6 T, was used to reduce the sawtooth period and increase the NTM βn onset level

Additional details

Identifiers

Publishing Information

Journal Title
AIP Conference Proceedings
Journal Volume
595
Journal Issue
1
Journal Page Range
p. 106-109
ISSN
0094-243X
CODEN
APCPCS

Conference

Title
14. topical conference on radio frequency power in plasmas
Dates
7-9 May 2001
Place
Oxnard, CA (United States)

Optional Information

Notes
(c) 2001 American Institute of Physics.