Dynamic evolution of microturbulence with an improved confinement mode in the ramp-down phase of plasma current on EAST
Dynamic evolution of microturbulence with an improved confinement mode in the ramp-down phase of plasma current on EAST
复制标题
EAST 等离子体电流斜坡下降阶段具有改进限制模式的微湍流动态演化
DOI：
10.1088/1361-6587/ab0937
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发表时间：
2019
影响因子：
2.2
通讯作者：
Zhao H L
中科院分区：
文献类型：
--
作者：
Bi J;Li Y D;Wu G J;Li P;Sun P J;Lan T;Wang S X;Zhao H L
微观不稳定性经常被用来解释聚变等离子体中能量和粒子的异常传输，其起源和对异常传输的贡献仍然不确定。利用实验先进超导托卡马克（EAST）上的极向CO 2 激光相干散射诊断系统同时研究了等离子体核心和梯度区微湍流的动态特征。 2018年，在没有辅助加热的当前斜坡下降阶段观察到一种以峰值密度分布为特征的改进限制模式，这很少被研究。实验结果表明，LHW 加热的逐渐关闭可能会触发模式转换。这种转变伴随着微湍流的极大抑制和互相关谱的显着变化。一种可能的抑制机制可归因于不断增加的
Micro-instabilities are often invoked to account for the anomalous transport of energy and particles in fusion plasmas, whose origin and contributions to anomalous transport remain uncertain. The dynamic features of the microturbulence in the plasma core and the gradient region are investigated simultaneously by a poloidal CO 2 laser coherent scattering diagnostic system on the experimental advanced superconducting tokamak (EAST). In 2018, an improved confinement mode characterized by a peaked density profile is observed in the current ramp-down phase with no auxiliary heating, which has rarely been studied. The experimental result suggests that the gradual shut off of the LHW heating might trigger the mode transition. The transition is accompanied with a great suppression of microturbulence and significant change in the cross-correlation spectrum. A possible mechanism for the suppression could be ascribed to the increasing