Divertor detachment and asymmetry in H-mode operation with an ITER-like tungsten divertor in EAST
Divertor detachment and asymmetry in H-mode operation with an ITER-like tungsten divertor in EAST
复制标题
EAST 中类似 ITER 的钨偏滤器在 H 模式操作中偏滤器脱离和不对称
DOI：
10.1088/1741-4326/ab4639
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发表时间：
2019-12-01
期刊：
影响因子：
3.3
通讯作者：
Wan, B. N.
中科院分区：
文献类型：
--
作者：
Liu, J. B.;Wang, L.;Wan, B. N.
最近，在EAST的H模等离子体中实现了分离偏滤器，这对于在不久的将来实现高功率长脉冲操作是必不可少的。偏滤器分离由粒子通量的翻转和电子温度下降至约5 eV指示，如由偏滤器靶处的朗缪尔探针测量的，随着等离子体密度增加。剥离的密度阈值随着加热功率的增加而增加，并且结合中性束注入（NBI）和射频加热比单独NBI更高。偏滤器分离对于有利的BT表现出强的进出不对称性，即离子B × 向X点方向漂移。相反，与反向环向场，外撞击点附近的粒子通量首先随着密度增加，然后保持几乎恒定，没有明显的翻转，当偏滤器等离子体进入分离制度，和内部和外部偏滤器之间的分离开始变得接近平衡，预期从漂移的影响。
The detached divertor has recently been achieved in H-mode plasmas in EAST with an ITER-like tungsten divertor, which is essential for high power long pulse operation in the near future. The divertor detachment is indicated by the rollover of particle flux and the drop in electron temperate down to ~5 eV, as measured by the Langmuir probes at the divertor target, as the plasma density increases. The density threshold of detachment increases with heating power, and is higher with combined neutral beam injection (NBI) and radiofrequency heating than NBI only. The divertor detachment exhibits a strong in–out asymmetry for favorable BT, i.e. with the ion B × drift direction toward the X-point. In contrast, with reverse toroidal field, the particle flux near the outer strike point first increases with density, then maintains nearly constant, without pronounced roll-over, when the divertor plasma enters the detachment regime, and the onset of detachment between inner and outer divertors becomes nearly balanced, as expected from the effect of drifts.