Study on H-mode access at low density with lower hybrid current drive and lithium-wall coatings on the EAST superconducting tokamak
Study on H-mode access at low density with lower hybrid current drive and lithium-wall coatings on the EAST superconducting tokamak
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DOI：
10.1088/0029-5515/51/7/072001
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发表时间：
2011-07
期刊：
影响因子：
3.3
通讯作者：
Guosheng Xu;Boyang Wan;Jiangang Li;X. Gong;Jiansheng Hu;J. Shan;Hong Li;D. Mansfield;D. A.
中科院分区：
文献类型：
--
作者：
Guosheng Xu;Boyang Wan;Jiangang Li;X. Gong;Jiansheng Hu;J. Shan;Hong Li;D. Mansfield;D. A.
在EAST超导托卡马克装置上，用约1 MW的低杂波功率获得了第一个高约束模（H模），H因子为HIPB_（98）（y，2）~（-1）。在等离子体击穿之前通过锂（Li）蒸发进行壁调节并且将精细Li粉末实时注入到等离子体边缘中之后，出现第一H模式等离子体。H模式接入的阈值功率遵循国际托卡马克标度，即使在低密度范围内，并已确定了密度阈值。随着沉积的Li的积累的增加，H模式的持续时间逐渐延长到3.6 s，对应于1030约束时间，仅受等离子体电流平顶的当前可达到的持续时间的限制。最后，观察到随着Li积累的增加，较低X点附近的中性密度逐渐降低4倍，这被认为是Li壁涂层降低H模式功率阈值的主要机制。
The first high-confinement mode (H-mode) with type-III edge localized modes at an H factor of HIPB98(y,2) ∼ 1 has been obtained with about 1 MW lower hybrid wave power on the EAST superconducting tokamak. The first H-mode plasma appeared after wall conditioning by lithium (Li) evaporation before plasma breakdown and the real-time injection of fine Li powder into the plasma edge. The threshold power for H-mode access follows the international tokamak scaling even in the low density range and a threshold in density has been identified. With increasing accumulation of deposited Li the H-mode duration was gradually extended up to 3.6 s corresponding to ∼30 confinement times, limited only by currently attainable durations of the plasma current flat top. Finally, it was observed that neutral density near the lower X-point was progressively reduced by a factor of 4 with increasing Li accumulation, which is considered the main mechanism for the H-mode power threshold reduction by the Li wall coatings.