Comparison between gas puffing and supersonic molecular beam injection in plasma density feedback experiments in EAST
Comparison between gas puffing and supersonic molecular beam injection in plasma density feedback experiments in EAST
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DOI：
10.1088/0741-3335/55/11/115010
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发表时间：
2013-10
影响因子：
2.2
通讯作者：
Xingwei Zheng;Jiangang Li;Jiansheng Hu;Jiahong Li;R. Ding;B. Cao;Jinhua Wu
中科院分区：
文献类型：
--
作者：
Xingwei Zheng;Jiangang Li;Jiansheng Hu;Jiahong Li;R. Ding;B. Cao;Jinhua Wu
为了实现理想的等离子体密度控制，最近为EAST托卡马克装置研制了一种超声分子束注入（SMBI）反馈控制系统。比较了SMBI反馈系统和吹气反馈系统的性能。采用GP进行密度反馈控制时，脉宽模式的性能优于脉幅模式。在一天的实验中，气体输入量和壁面滞留量的变化可以分为两个阶段。在第一阶段中，保留率高达80- 90%，并且气体输入约为1022 D2的数量级。然而，在第二阶段，保留率在50- 70%的范围内。单次放电的气体输入量较小，网壁滞留量增长缓慢。分析了SMBI反馈控制实验的结果。SMBI较短的延迟时间使其更快地反馈控制等离子体密度。结果表明，与GP相比，SMBI的气体输入量减少了约30%，壁面滞留量减少了约40%。这表明SMBI在EAST长脉冲高密度放电中的优越性。
To achieve desirable plasma density control, a supersonic molecular beam injection (SMBI) feedback control system has been developed recently for the EAST tokamak. The performance of the SMBI and gas puffing (GP) feedback systems were used and compared. The performance of pulse width mode is better than that of pulse amplitude mode when GP was used for density feedback control. During one-day experiments, the variation of gas input and wall retention can be clarified into two stages. In the first stage the retention ratio is as high as 80–90%, and the gas input is about an order of 1022 D2. However, in the second stage, the retention ratio is at a range of 50–70%. The gas input of a single discharge is small and the net wall retention grows slowly. The results of the SMBI feedback control experiment was analyzed. The shorter delay time of SMBI makes it faster at feeding back control the plasma density. The result showed that, compared with GP, the gas input of SMBI was decreased ∼30% and the wall retention was reduced ∼40%. This shows SMBI's advantage for the long pulse high density discharges in EAST.