Fast measurement of ELM heat and particle fluxes, and plasma flow in the scrape-off layer of the JT-60U tokamak
Fast measurement of ELM heat and particle fluxes, and plasma flow in the scrape-off layer of the JT-60U tokamak
复制标题
快速测量 JT-60U 托卡马克刮除层中的 ELM 热量和粒子通量以及等离子体流
DOI：
10.1088/0741-3335/44/5a/333
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发表时间：
2002
影响因子：
2.2
通讯作者：
Y. Sakamoto
中科院分区：
文献类型：
--
作者：
N. Asakura;S. Sakurai;O. Naito;K. Itami;Y. Miura;S. Higashijima;Y. Koide;Y. Sakamoto
研究了导致等离子体在转化器靶上快速沉积的ELM热和粒子通量的输运过程。利用JT-60U托卡马克上的静电探针（马赫探针），首次在ELMy \mbox{h模}等离子体中测量了沿场线驱动的剥离层（SOL）等离子体流动，测量了三个重要位置（即外中平面、x点和高场侧SOL）。测定了等离子体流动的径向分布。在低场侧SOL的x点以下，ELM事件发生后200-300µs内，流速快速增加，达到离子声速水平，径向宽度为1.0-1.5 cm（映射到中层SOL）。快速等离子体流的持续时间和宽度与红外电视摄像机（250µs时间分辨率）测量的外导流器目标的热负荷沉积时间和宽度相当。简单的模式分析表明，对流输送对ELM热沉积过程有很大贡献。另一方面，在高场侧SOL中，ELM事件后没有观察到内部导流器的SOL流动。简单的对流输运模型不能解释高场侧太阳SOL中的ELM热通量和粒子通量。
The transport process of ELM heat and particle fluxes responsible for the rapid plasma deposition on the divertor target was investigated. The scrap-off layer (SOL) plasma flow driven along the field lines was measured in the ELMy \mbox{H-mode} plasma, for the first time, at three important locations (i.e. outer midplane, x-point and high-field-side SOL) using electrostatic probes (Mach probe) on the JT-60U tokamak. The radial profiles of the plasma flow were determined. Just below the x-point of the low-field-side SOL, a rapid increase in the flow velocity up to the ion sonic level was observed during 200-300 µs after ELM events, and the radial width was 1.0-1.5 cm (mapping to the midplane SOL). The duration and width of the rapid plasma flow were comparable to the deposition duration and width of the heat load to the outer divertor target measured with an infrared TV camera (250 µs time resolution). A simple model analysis showed that convective transport gives a large contribution to the ELM heat deposition process. On the other hand, at the high-field-side SOL, SOL flow towards the inner divertor was not observed after ELM events. The ELM heat and particle fluxes in the high-field-side SOL were not explained by the simple convective transport model.