|
Experimental characteristics of a lower hybrid wave multi-junction coupler in the HT-7 tokamak
丁伯江, 单家方, 刘甫坤, 方瑜德, 韦 维, 吴振伟, 陈忠勇, 徐汉东, 王 茂, 蒋 敏, 张公让, 黄 峰, 赵燕平, 匡光力, HT-7 team
2006 (12):
2989-2999.
doi: 10.1088/1009-1963/15/12/037
摘要
(
1435 )
PDF(528KB)
(
568
)
A phase-controlled lower hybrid wave (LHW) multi-junction (MJ) coupler
(3(rows)×(columns)× (subwaveguides)) has been developed in the
HT-7 tokamak. Simulations show that it is more effective for driving plasma current
than an ordinary phase-controlled LHW antenna (3(rows)×12(columns))
(traditional coupler). The plasma--wave coupling experiments show that the
reflection coefficient (RC) is below 10%, implying that the MJ grill can launch
the wave into the plasma effectively. The effect of power spectrum launched by the
MJ coupler on RC indicates that an optimal condition is requisite for a better
coupling in the lower hybrid current drive (LHCD) experiments. Studies indicate that
the drive efficiency of the MJ antenna is higher than that of the traditional one,
which is mainly ascribed to the discrepancy in impurity concentration, plasma
temperature, and spectrum directivity. An improved confinement with an electron
internal transport barrier is obtained by LHCD. The analysis shows that the
modified negative (low) magnetic shear and the change of radial electric field
profile due to LHCD are possible factors responsible for the eITB formation.
相关文章 |
计量指标
|