Abstract - EAST摘要东.ppt

Thank you! ASIPP Long pulse and high power LHCD plasmas on HT-7 Xu Qiang Abstract Long pulse plasma (up to 400 s) has been achieved by lower hybrid current drive (LHCD) on HT-7 tokamak. High power current drive of lower hybrid wave (up to 800 kW) was also performed recently. The lower hybrid wave (LHW) power scan was performed in the plasma parameter ranges of IP = 130 and 160 kA, ?ne = 1.5×1019 m-3, PLHW = 70 – 800 kW. The lower hybrid current drive (LHCD) efficiency is studied for different injected powers and for different densities. Improved particle confinement is observed by application of LHCD as characterized by an increase of central line averaged electron density and decrease of D? emission. The dependence of energy confinement time (?E) on plasma density and LHW power is experimentally studied in detail. Introduction of the HT-7 tokamak The HT-7 tokamak is superconducting device, which was rebuilt from the original Russian T-7 tokamak in 1994. It has amajor radius of R = 1.22 m, minor radius of a = 0.27 m in the circular cross-section. There are two layers of thick copper shells, and between them 24 superconducting coils are located, which can create and maintain extremely a toroidal magnetic field Bt of 2.5 T. In the first experimental campaign of the 2007, we made the high power experiments, the power of the LHCD system is up to 800kW. Overview of HT-7 Experimental setup Ip = 100~250 kA (250) ?ne = 1~8x1019m-3 (6.5) Te = 1~5 keV (4.5) Ti = 0.2~1.5 k eV (1.5) ICRF: f = 15~30MHz, P = 0.3MW(0.35) f = 30~110MHz, P = 1.5MW LHCD: f = 2.45GHz, P = 1.2MW(0.8) A typical long-pulse LHCD discharge (toroidal field Bt = 1.8 T, injected LHW power PLHW = 100 kW) on HT-7 A typical high power current drive of lower hybrid wave on HT-7 LHCD efficiency The current drive efficiency is an important physical quantity in evaluating the lower hybrid current drive experiment. The experimental current drive efficiency is defined by ?exp=?neRIrf