Sawtooth and neoclassical tearing mode seed island control by ICRF current drive on JET
2001 (English)In: RADIO FREQUENCY POWER IN PLASMAS / [ed] Mau TK; DeGrassie J., 2001, Vol. 595, 106-109 p.Conference paper (Refereed)
In recent experiments at JET, ICRF waves were used to either stabilise or destabilise sawteeth, and consequently control the formation of the seed island responsible for the appearance of Neoclassical Tearing Modes (NTMs) known to limit the tohamak performance. Two scenarios were studied in deuterium plasmas with a hydrogen concentration of 5 to 10 %. Firstly, using a toroidal magnetic field B-0 of 2.5T, the fundamental hydrogen cyclotron resonance layer (omega=omega(cH)) was positioned at the High Field Side (HFS) at the sawtooth inversion radius (R(inv)similar toR(q=1)). With +90degrees phased wave, monster sawteeth were obtained that triggered NTMs. Secondly, ICRF waves at the 2(nd) harmonic hydrogen cyclotron resonance (omega=2omega(cH)) positioned at the Low Field Side (LFS) with B-0 between 1.2T and 1.6T, was used to reduce the sawtooth period and increase the NTM beta(n) onset level.
Place, publisher, year, edition, pages
2001. Vol. 595, 106-109 p.
, AIP CONFERENCE PROCEEDINGS, ISSN 0094-243X
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:kth:diva-25667DOI: 10.1088/0029-5515/42/11/306ISI: 000173023300014ISBN: 0-7354-0038-5OAI: oai:DiVA.org:kth-25667DiVA: diva2:359319
14th Topical Conference on Radio Frequency Power in Plasmas OXNARD, CA, MAY 07-09, 2001 Gen Atom; Univ Calif San Diego; Amer Inst Phys
QC 201010272010-10-272010-10-272010-10-27Bibliographically approved