Dissipation of runaway current by massive gas injection on J-TEXT

被引：7

作者：

Wei, Y. N. ^{[1
]}

Yan, W. ^{[1
]}

Chen, Z. Y. ^{[1
,2
]}

Tong, R. H. ^{[1
]}

Lin, Z. F. ^{[1
]}

Zhang, X. L. ^{[1
]}

Jiang, Z. H. ^{[1
]}

Yang, Z. J. ^{[1
]}

Ding, Y. H. ^{[1
]}

Liang, Y. ^{[1
,3
,4
]}

机构：

[1] Huazhong Univ Sci & Technol, Int Joint Res Lab Magnet Confinement Fus & Plasma, State Key Lab Adv Electromagnet Engn & Technol, Sch Elect & Elect Engn, Wuhan 430074, Hubei, Peoples R China

[2] Chengdu Univ, Chengdu 610106, Sichuan, Peoples R China

[3] Forschungszentrum Julich, Inst Energie & Klimaforsch Plasmaphys, D-52425 Julich, Germany

[4] Chinese Acad Sci, Inst Plasma Phys, POB 1126, Hefei 230031, Anhui, Peoples R China

来源：

PLASMA PHYSICS AND CONTROLLED FUSION | 2020年 / 62卷 / 02期

基金：

中国博士后科学基金; 中国国家自然科学基金;

关键词：

MGI; runaway current; dissipation; assimilation;

D O I：

10.1088/1361-6587/ab52c8

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

Plasma disruption is one of the major challenges for ITER. A large fraction of runaway current may be formed due to the avalanche generation of runaway electrons (REs) in disruptions. Current researches find that the generation of REs may be hard to totally suppress during the disruptions, and lead to the formation of large runaway current in future fusion devices. Runaway currents carry huge magnetic and kinetic energies that need to be dissipated safely. Runaway current dissipation by high-Z impurities has been performed on J-TEXT. Runaway currents are formed by an injection of ?10(19) argon atoms, and then large quantities of argon or krypton impurities are injected by the massive gas injection valve to dissipate the runaway current during the runaway current plateau phase. The dissipation efficiency increases with the increase of injected impurity quantity. When the injected impurity quantity exceeds 210(21), the dissipation efficiency becomes saturated. Up to a 28 MA s(?1) runaway current dissipation rate and a 15% energy dissipation rate can be achieved. Analysis shows that the saturation of dissipation efficiency is caused by the decrease of impurity assimilation rate with the increase of total injected impurity quantity. The decrease of impurity assimilation rate may be caused by the saturation of impurity density growth rate during the short dissipation phase. A simple estimate also shows that the increase of internal inductance leads to the slowing down of the growth of runaway current dissipation rate during the runaway current decay phase. The results may have important implication for ITER disruption mitigation.

引用

页数：13