Eur. Phys. J. D 42, 269-272 (2007)
https://doi.org/10.1140/epjd/e2007-00025-9

Multifaceted asymmetric radiation from the edge along improved confinement mode in LHCD plasmas with graphite limiters on HT-7 tokamak

¹ Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Anhui, 230031, P.R. China
² Directorate of Plasmas and Fusion, Pakistan Institute of Nuclear Science and Technology, Islamabad, 04770, Pakistan

Corresponding author: ^a dr.muh.asif@gmail.com

Received: 21 November 2006
Revised: 12 January 2007
Published online: 9 February 2007

Abstract

Multifaceted asymmetric radiation from the edge (MARFE) phenomena during lower hybrid current drive (LHCD) Experiments on the HT-7 superconducting tokamak are summarized in this paper. The best correlation has been found between the total input (ohmic + LHCD) power and the product of the edge line average density and Z_eff. Studies show that the critical density of MARFE onset is observed in the region of Z_eff^1/2f_GW = 0.6-0.9, where , (here 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. Improved confinement mode induced by a MARFE is observed, and it is maintained for about 65 ms. MARFE cools the plasma edge, and the electron density profile is observed to become more narrow and peaked.