Plasma-facing components damage and its effects on plasma performance in EAST tokamak
Plasma-facing components damage and its effects on plasma performance in EAST tokamak
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DOI：
10.1016/j.fusengdes.2020.111616
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发表时间：
2020-07
影响因子：
1.7
通讯作者：
B. Gao;R. Ding;Hai Xie;L. Zeng;Ling Zhang;Baoguo Wang;Changjun Li;Dahuan Zhu;R. Yan;Junling Chen
中科院分区：
文献类型：
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作者：
B. Gao;R. Ding;Hai Xie;L. Zeng;Ling Zhang;Baoguo Wang;Changjun Li;Dahuan Zhu;R. Yan;Junling Chen
在托卡马克运行过程中，等离子体-壁相互作用（PWI）会严重损坏面向等离子体的元件（PFC），从而导致PFC表面释放的杂质引起的辐射损失，导致等离子体性能下降。在EAST装置上对PFC的损伤及其对等离子体性能的影响进行了实验研究。LHCD天线防护限制器处的热点和W上部偏滤器的钨（W）熔化过程产生了大量粉尘，由于高辐射损失导致中断。降低辅助加热功率或将击穿点位置从熔化点移开可以有效地恢复钨熔化引起的等离子体放电。统计分析表明，分别约12.0%和38.3%的中断是由于2017年和2018年活动中强PWI工艺的严重杂质爆发。在2018年活动中，由于钨杂质爆发导致的等离子体中断约为26.3%，远高于2017年活动的4.8%。这是由于较高的辅助加热功率、W PFC上较大的未对准和新的W保护限制器。PFC损伤对等离子体运行的影响的主要特点。
During the tokamak operations, plasma-wall interactions (PWI) can severely damage the plasma-facing components (PFCs), which will lead to degradation of plasma performance due to radiation losses by the impurities released from the damaged PFCs surfaces. The PFCs damage and its effects on the plasma performance are studied experimentally for the EAST tokamak. Substantial dusts were generated from the hot spots at the guard limiter of LHCD antenna and the tungsten (W) melting processes from the W upper divertor, which results in disruption due to high radiation losses. Two methods can be effectively used to recover the plasma discharges after tungsten melting induced disruptions, reducing the auxiliary heating power or moving away the position of strike point from the melting site. Statistics analysis indicate that about 12.0 % and 38.3 % of disruptions were due to severe impurity burst from the strong PWI processes in 2017 and 2018 campaign, respectively. In 2018 campaign, the plasma disruption due to tungsten impurity burst is about 26.3 %, which is much higher than 4.8 % in 2017 campaign. This is due to the higher auxiliary heating power, larger misalignment on W PFCs and the new W guard limiter. The main features on the effects of PFC damage on plasma operation are shown.