HL-2A等离子体中比压阿尔芬-声波模及其控制的实验研究

Recently, Alfvenic modes have received considerable renewed theoretical and experimental attention in the light of questions raised as to their stability in the presence of fastparticles in the field of magnetic confinement fusion.Smongst these, Beta-induced Alfvén-acoustic eigenmode(BAAE),can interact resonantly with the fusion produced particles and have deleterious effects on plasma performance arising from the induced fast ion loss and wall heat load.However,the study on the mechanism of energetic particles on BAAE is still in its infancy.Despite some theories and models have been proposed,a full explaination of many phenomena is not yet acquired.The role of BAAE activity on ITER and future fusion reactors for avoiding fast particle lose remains uncertain, and in-depth study on its working mechanism is thus urgently desired.Exploration of the mechanism of its triggering and damping is of great significance for the pridiction of energetic particle transport in ITER.In this program,relying on the national science and engineering of HL-2A tokamak device and focusing on the above-mentioned key issues,with the design of delicate expriments,we plan to invastigate the features of of BAAE and its control systematically,and then summarize experimental results with variant key plasma parameters,aiming to reveal the inside potential physics combined with the present theories and modelling.

近年来，由高能粒子驱动的各种阿尔芬模对高能粒子输运的作用越发受到国际磁约束聚变界的广泛重视，其中包括由阿尔芬波与离子声波耦合而形成的比压阿尔芬-离子声波（BAAE）本征模。然而，探索高能粒子与BAAE等阿尔芬模的相互作用机理的工作仍处于起步阶段。针对BAAE不稳定模可能在ITER及今后的反应堆中对快粒子损失的作用，迫切需要深刻了解其激发与阻尼等相关潜在物理机制。尽管BAAE本征模已经被众多理论、模拟和实验结果所证实，而等离子体对BAAE模的阻尼作用机理及该不稳定性与高能粒子的相互作用研究，对于预测ITER 中 BAAE模的行为及其对高能粒子损失的影响具有重要意义。本项目将围绕上述ITER关键问题，依托国内大型聚变实验装置HL-2A托卡马克，设计有针对性的物理实验，就BAAE模的激发与阻尼尤其是其主动控制展开系统实验研究，并结合已有理论模型，深入探索潜在物理机制。

快离子损失探针系统得到优化和拓展，测量到包括BAAE模在内的高频的MHD导致的快离子损失；具备高适应性的贝叶斯方法在聚变数据分析中的分析方法建立。重要结果是发现了高能电子驱动的阿尔芬模，发现了比压型阿尔芬-离子声波模的分裂和阻尼，特别是阿尔芬模的阻尼在逃逸电子的主动抑制中的作用、在国际上首次发现了新经典撕裂模与非局域输运的相互作用，磁岛与等离子体流和湍流之间的相互作用等。