Study of MARFE during lower hybrid current drive in HT-7 tokamak

Lower hybrid current drive (LHCD) experiments have been carried out to achieve high performance for long pulse operation in the HT-7 superconducting tokamak. Multifaceted asymmetric radiation from the edge (MARFE) phenomena, is observed in LHCD plasmas when P LH > 160   kW and edge safety factor...

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Bibliographic Details
Published inPhysics letters. A Vol. 346; no. 4; pp. 305 - 309
Main Authors Asif, M., Gao, X., the HT-7 Team
Format Journal Article
LanguageEnglish
Published Elsevier B.V 17.10.2005
Subjects
Electron density
LHCD plasmas
MARFEs
Plasma edge
52.55.Fa
MARFEs
LHCD plasmas
Plasma edge
Electron density
52.40.Hf
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Summary:Lower hybrid current drive (LHCD) experiments have been carried out to achieve high performance for long pulse operation in the HT-7 superconducting tokamak. Multifaceted asymmetric radiation from the edge (MARFE) phenomena, is observed in LHCD plasmas when P LH > 160   kW and edge safety factor q ( a ) is slightly less than 6.5 and has been studied in this Letter. Studies show that the critical density of MARFE onset is observed in the region of Z eff 1 / 2 f GW = 0.6 – 0.9 , where f GW = n ¯ e n GW (here n ¯ e is the maximum line average electron density and n GW is the Greenwald density). These MARFEs generally appear to have the same characteristics as high f GW MARFEs and are positionally stable throughout the LHCD pulse.
ISSN:0375-9601
1873-2429
DOI:10.1016/j.physleta.2005.08.029