Runaway current suppression by secondary massive gas injection during the disruption mitigation phase on J-TEXT
Runaway current suppression by secondary massive gas injection during the disruption mitigation phase on J-TEXT
复制标题
DOI：
10.1088/1361-6587/ab210b
复制
发表时间：
2019-06
影响因子：
2.2
通讯作者：
Y. Wei;W. Yan;Z. Chen;R. Tong;Z. Jiang;Z. Yang
中科院分区：
文献类型：
--
作者：
Y. Wei;W. Yan;Z. Chen;R. Tong;Z. Jiang;Z. Yang
扰动可能引起热负荷、晕流和逃逸电子，是未来托卡马克急需解决的问题之一。大量杂质注入是减轻这种破坏的可行方法。由于杂质注入速率和同化效率的限制，在未来的大型装置中，单次注入杂质可能不足以完全抑制稀土的产生。大量的RE可以形成失控电流并且在等离子体电流中携带大的电流部分。为了抑制失控电流的形成，在J-TEXT上执行从附加阀到中断缓解系统的阀的具有延迟时间的二次气体注入。当额外的高Z杂质气体到达等离子体边缘之前的热淬火，失控电流可以显着抑制通过削弱初级RE产生。最终形成的失控电流可减少90%。当额外的高Z杂质气体到达等离子体边缘时，在电流猝灭过程中，可以通过削弱雪崩RE的产生来部分抑制失控电流。最终形成的飞逸电流可减少40%~ 80%。
Disruption is one of the urgent problems for future tokamaks in possibly causing heat loads, halo currents, and runaway electrons (REs). Massive impurity injection is a feasible way to mitigate the disruption. Due to the limit of the impurity injection rate and the assimilation efficiency, single injection of impurity may not be sufficient to totally suppress RE generation in future large-scale devices. Large number of REs can form runaway currents and carry a large current fraction in the plasma current. In order to suppress the formation of the runaway current, a secondary gas injection from an additional valve with a delay time to the valve of the disruption mitigation system is performed on J-TEXT. When the additional high-Z impurity gas arrives at the plasma edge before the thermal quench, the runaway current can be significantly suppressed by weakening the primary RE generation. The final formed runaway current can be reduced by 90% in this way. When the additional high-Z impurity gas arrives at the plasma edge during the current quench, the runaway current can be partially suppressed by weakening the avalanche RE generation. The final formed runaway current can be reduced by 40%–80% in this way.