Minor disruptions triggered by supersonic molecular beam injection on the J-TEXT tokamak
Minor disruptions triggered by supersonic molecular beam injection on the J-TEXT tokamak
复制标题
J-TEXT 托卡马克超音速分子束注入引发的轻微破坏
DOI：
10.1088/1741-4326/ab7d19
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发表时间：
2020
期刊：
影响因子：
3.3
通讯作者：
Zhong yong Chen
中科院分区：
文献类型：
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作者：
Zhonghe Jiang;TingTing Yang;Jianjun Yuan;Changhong Li;Xin Ye;Jing Huang;Yunfeng Liang;Valerie A Izzo;MingXiang Huang;Ruihai Tong;Yuan Huang;Qinxue Cai;Xingting Yan;Lizhi Zhu;Zhoujun Yang;Yong Hua Ding;Ping Zhu;Zhong yong Chen
利用超声分子束注入氩气对J-TEXT进行了破坏减缓实验，研究了多级小破坏的演化过程。使用3D磁流体动力学（MHD）代码，即尼姆罗德（Sovinec等人2004 J. Comput. Phys. 195 355）。实验和数值模拟结果如下所示。中心等离子体温度下降到小于几十个电子伏后，一个相对较长的时间的多级热崩溃。当杂质冷锋向q = 2表面传播时，出现不同的MHD不稳定性模。在MHD活动爆发和中心等离子体热塌缩过程中，热通量从核心区域转移到等离子体边界。进一步的数值模拟结果表明，MHD过程是伴随着显着增加的核心定向传播的杂质通过q = 2的表面。在小破裂向大破裂的过渡阶段，高阶模起着重要作用，n = 3模的增长率甚至比n = 1或n = 2模的增长率还要大。区分大破坏和小破坏的似乎是，在一个小破坏中，一次MHD碰撞不足以引起完全的辐射坍缩。
Disruption mitigation experiments with supersonic molecular beam injection of argon gas on J-TEXT were conducted to explore the evolution process during multistage minor disruption. The corresponding numerical simulation was performed using a 3D magnetohydrodynamic (MHD) code, namely, NIMROD (Sovinec et al 2004 J. Comput. Phys. 195 355). The experimental and numerical simulation results are shown in the following. The central plasma temperature decreases to less than tens of electovolts after a relatively long period of multistage thermal collapse. Different MHD instability modes appear when the impurity cold front propagates toward the q = 2 surface. During the burst of MHD activity and central plasma thermal collapse, the heat flux is transferred from the core region to the plasma boundary. Further numerical simulation results show that the MHD process is accompanied by a significant increase in the core-oriented spread of impurities through the q = 2 surface. During the transition stage from the minor disruption to the major disruption, the high order modes play an important role and the magnitude of the n = 3 growth rate is even larger than that of the n = 1 or n = 2 mode. What seems to separate major from minor disruptions is that in a minor disruption, a single MHD crash is not sufficient to cause a full radiative collapse.