托卡马克等离子体中漂移波湍流、测地声模与高能量粒子的复杂相互作用的理论研究

The confinement of a magnetically confined fusion device is determined by its anomalous transport, which is determined by the level of electromagnetic/electrostatic turbulences. Excitation of Geodesic acoustic mode is one of the saturation mechanism of electrostatic drift wave turbulence, and it can also be resonantly driven by energetic particles in a tokamak. The correct understanding of the nonlinear interactions between drift wave turbulences, geodesic acoustic mode and energetic particles is of crucial importance for the understanding of the confinement of tokamak plasma.In this program, we will study the complex nonlinear interactions between drift wave turbulence, geodesic acoustic mode and energetic particles and hence the nonlinear saturation of drift wave turbulence, using both first-principle-based gyrokinetic theory and numerical simulations. Furthemore, we will study the long time scale evolution of the energetic particle distribution function and the radial pressure profile of bulk plasma, and investigate the L-H transition mechanism in tokamak plasmas due to excitation of geodesic acoustic mode. Our anticipated results, will not only provide in-depth understanding for the present and future experimental and numerical results, but also be of interest to the expected complex multiple-scale physics expected in fusion plasmas.

磁约束聚变装置的约束性能取决于其反常输运水平，是由其中的静电/电磁湍流的幅度所决定。静电的漂移波的饱和机制之一是测地声模带状流的激发，其也受到托卡马克中高能量粒子的共振激发。正确理解漂移波湍流—测地声模—高能量粒子的非线性相互作用对理解托卡马克的约束水平至关重要。 本项目将在我们多年前期工作的基础之上，从基于第一性原理的回旋动理学理论出发，结合数值模拟，研究漂移波湍流—测地声模—高能量粒子的复杂非线性相互作用，从而理解漂移波湍流非线性饱和的物理机制；并理解此过程中高能量粒子分布函数和等离子体径向压强剖面的长时间尺度演化，从而研究托卡马克中L-H转换的物理机制。 预期的结果不光将对理解现有的实验和模拟结果，以及对将来进一步的改善国际热核反应堆（ITER）及国内装置中的约束性质，提供理论支持；还将促进聚变等离子体中的复杂多尺度物理的研究。

本项目按照申请书计划执行，研究高能量粒子、测地声模、漂移波湍流之间的非线性相互作用，特别关注其导致的高能量粒子测地声模的自洽非线性相互演化、漂移波/漂移阿尔芬波的非线性演化及饱和过程，以及对应的等离子体的输运水平。本项目执行中共发表论文11篇，其中包括一篇测地声模动理学理论的系统综述，一篇Physiccal Review Letter文章,另有两篇正在审稿中；在学术会议做邀请报告两次；培养博士生两名。