Sustained radiative divertor in high-performance grassy-ELM regime with metal wall towards long-pulse operation in EAST
Sustained radiative divertor in high-performance grassy-ELM regime with metal wall towards long-pulse operation in EAST
复制标题
高性能草地 ELM 体系中的持续辐射偏滤器，具有金属壁，可在 EAST 中实现长脉冲操作
DOI：
10.1016/j.nme.2020.100867
复制
发表时间：
2021
影响因子：
2.6
通讯作者：
Wan B. N.
中科院分区：
文献类型：
--
作者：
Li K. D.;Xu G. S.;Yuan Q. P.;Wang L.;Yang Z. S.;Liu J. B.;Yang Q. Q.;Wu K.;Duan Y. M.;Xu J. C.;Meng L. Y.;Wang H. Q.;Guo H. Y.;Ding F.;Chen M. W.;Zhang L.;Yan N.;Tao Y. Q.;Li E. Z.;Zeng L.;Zhang B.;Gong X. Z.;Xiao B. J.;Luo G. N.;Wan B. N.
金属壁环境下大幅值边缘局域模式(ELMS)引起的暂态热载荷和偏滤器靶上的稳态热载荷的同时控制是未来托卡马克聚变堆(如ITER和中国聚变工程试验堆)稳态运行的关键。在最近的实验中，我们采用了一种新的剥离反馈控制方案，在Q95~Q5.9的高性能草叶H模实验先进超导托卡马克(EAST)中实现了持续的部分能量剥离。在该方案中，我们首先利用偏滤器朗缪尔探针测量的电子温度(TET)来识别能量剥离的开始，然后切换到绝对极紫外光(AXUV)系统测量的总辐射功率的反馈控制。在上外偏滤器注入80%Ne和20%D2的混合气体的情况下，成功地将上外撞击点附近的TET维持在8 eV以下。总辐射功率维持在1.4 mW左右，约为注入功率的52%。在整个分离反馈控制过程中，等离子体储能和H_(98)、Y_2因子(~1)没有明显下降。这些实验结果表明，高性能草榆片与辐射偏滤器具有良好的兼容性。为了在更大范围内确认两者的兼容性，EAST还通过新开发的集成反馈控制技术实现了相对较低的q95(~5.4)的稳定的草榆树H模部分能量分离。这种新的无约束退化的分离反馈控制为未来的EAST长脉冲运转提供了一种新的模式，可以很好地控制偏滤器靶上的ELM诱导的瞬时和稳态热流密度。
Simultaneous control of transient heat load induced by large-amplitude edge-localized modes (ELMs) and steady-state heat load on divertor targets under metal wall environment is crucial for steady-state operation of future tokamak fusion reactors, such as ITER and the China Fusion Engineering Test Reactor (CFETR). In the recent experiments, sustained partial energy detachment without confinement degradation has been achieved in the Experimental Advanced Superconducting Tokamak (EAST) in high-performance grassy-ELM H-mode withq95~ 5.9 by a newly developed detachment feedback control scheme, in which we first used electron temperature (Tet) measured by divertor Langmuir probes to identify the onset of energy detachment, and then the system switched to the feedback control of total radiation power measured by absolute extreme ultraviolet (AXUV) system.Tetaround the upper outer strike point was successfully maintained less than 8 eV with seeding of 80% Ne and 20% D2mixture from upper outer divertor, and the total radiation power was maintained ~1.4 MW, around 52% of injected power. There was no significant decrease of the plasma stored energy andH98,y2factor (~1) over the entire detachment feedback control process. These experiment results demonstrate good compatibility of the high-performance grassy-ELM regime with radiative divertor. In order to confirm the compatibility in a wider range, stable partial energy detachment in grassy-ELM H-mode with relatively lowerq95(~5.4) was also achieved in EAST through the newly developed integrated-feedback-control technique. The new detachment feedback control without confinement degradation in grassy-ELM H-mode provides a candidate mode for EAST long-pulse operation in the future with well control of ELM-induced transient and steady heat fluxes on the divertor target.