聚变等离子体中测地声模与漂移波湍流非线性相互作用的理论研究

This project will be devoted to investigation of the excitation of geodesic acoustic mode by drift wave turbulence and the effects of geodesic acoustic mode on drift wave turbulence spreading, using the advanced, first-principle theoretical tools, under realisitic fusion plasma parameters and complex geometric configerations. We will generalize the paradigm of three-wave resonant parametric decay instability to describe the nonlinear interactions between geodesic acoustic mode and drift wave turbulence. We will first derive the general nonlinear equations describing the nonlinear interactions between geodesic acoustic mode and drift wave turbulence from gyrokinetic theory, and then study the effects of various kinetic effects and nonuniformities, such as finite system size, nonuniform drift wave frequencies and the continuous spectrum of geodesic acoustic mode, on the geodesic acoustic mode and drift wave turbulence nonlinear interactions. Based on this, we will study the drift wave turbulence spreading under the modulation of geodesic acoustic mode to understanding the size scaling laws of the confinement properties of toakamak fusion plasma. Our anticipated result, will not only provide in-depth understanding for the present experimental and numerical results, but also provide theoretical support on the crucial issue of how to improve confinement in the future ITER plasma.

本项目致力于从先进的、基于第一性原理出发的理论工具出发，研究在真实聚变等离子体参数和复杂几何位型下漂移波湍流对测地声模的激发，以及测地声模对漂移波湍流扩散的影响。我们将应用三波共振参量衰变不稳定性的图像来描述测地声模与漂移波湍流的相互作用。 我们将首先从回旋动理学理论出发来推导普适的描述测地声模与漂移波非线性作用的方程，并研究实际聚变等离子体参数条件下各种动理学效应及等离子体不均匀性（如有限系统尺度、漂移波频率的不均匀性及测地声模的连续谱等）对测地声模与漂移波湍流的相互作用的影响。并在此基础上，研究由于测地声模的调制对漂移波湍流的扩散的影响，从而理解托卡马克等离子体中的约束性能与装置的尺度的定标率。预期的结果不光将对理解现有的实验和模拟结果，还将对将来进一步改进国际热核聚变反应堆（ITER）中的约束性质，提供理论支持。