关于J-TEXT托卡马克上微撕裂模电磁湍流及其输运的实验研究

Magnetic-Confined-Fusion research, represented by tokamak, has been widely recognized as the most promising way for controlled fusion energy. High-Beta operation of tokamak is considered the major scenario because of its high fusion gain, high bootstrap current and economy. It is known Electro-Magnetic turbulence, especially Micro-Tearing mode become unstable and may play an important role in confinement and transport in high-Beta operation. Therefore, there is urgent need on the experimental study of Micro-Tearing mode. This project proposes to study Micro-Tearing mode and associated transport experimentally. Utilizing J-TEXT tokamak and its diagnostics, especially laser polarimeter, it is proposed to observe Micro-Tearing mode directly from experiment. Based on the observation, the parametric dependence of its growth rate will be studied by analyzing the relation between saturation level and plasma parameters. Its effect on transport will also be quantitatively explored by studying the relation between its saturation and plasma transport level. These results will help to understand Micro-Tearing mode and provide reference to improve confinement and transport in high-beta operation.

以托卡马克为代表的磁约束聚变研究被认为是最可能获取可控核聚变能的途径。托卡马克的高比压运行模式具有高聚变反应率、高自举电流和经济性等优点，是未来聚变堆运行的主要模式之一。研究表明，在高比压条件下，电磁湍流，特别是微撕裂模容易被激发，并可能成为影响输运与约束的主要因素。因此，开展关于微撕裂模的研究具有重要意义。本课题拟开展关于微撕裂模增长机制及其对输运影响的实验研究。基于J-TEXT托卡马克，以激光偏振仪为主，结合其他诊断，实现对微撕裂模的直接观测。分析微撕裂模饱和幅度与主要等离子体参数的关系，探索其增长机制。同时研究其饱和幅度与整体输运水平的关系，定量地评估该模式对等离子体输运的影响。课题研究成果预期可加深对微撕裂模的理解，为高比压运行下等离子体约束与输运的改善提供参考。

以托卡马克为代表的磁约束聚变研究被认为是最可能获取可控核聚变能的途径。在托卡马克中，等离子体湍流引起的反常输运是实现可控核聚变能源道路上所遇到的主要障碍之一。因此，开展关于等离子体湍流及输运的研究，对于人们尽快掌握可控核聚变能源具有重要意义。本课题基于J-TEXT托卡马克，以激光偏振仪为主，结合静电探针等其他诊断，对欧姆加热等离子体中的湍流开展了系统的实验研究。具体地，本课题主要开展了以下研究并取得了以下重要结果：1）升级了J-TEXT装置偏振干涉仪系统的探测器系统，使其工作更加稳定，测量信号的信噪比也有所增加；2）在偏振干涉仪系统上发展了前向相干散射的测量，实现了对等离子体内部静电湍流的测量，并利用探测光在等离子体中传播的折射效应，发明了前向相干散射分辨湍流传播方向的新方法；3）实现了对J-TEXT托卡马克欧姆运行区间内等离子体涨落的观测；4）观测到了低频准相干模与密度极限破裂的相关性。课题研究成果预期可加深对等离子体湍流的理解，为等离子体约束与输运的改善提供参考。