托卡马克锯齿振荡中q=1髙阶模式物理特性的大规模数值模拟研究

Exploring the property of high confinement mode (H-mode) is the primary concern in the international tokamak plasma physics, and hence it is necessary to understand the physical mechanism of the magnetohydrodynamics (MHD) instabilities and employ the feedback control. Based on the experiments in EAST and HL-2A, we plan to conduct the large-scale numerical simulation of the property of high-order harmonic q=1 modes (such as m/n=2/2 and m/n=3/3 harmonics) during sawtooth crashes in H-mode plasmas. The characteristics of such mode generation and its dependence on plasma parameters will be investigated. The focus is put on the effects of these high-order harmonics on the partial crash and the heat loss. Moreover, we will study in detail the nonlinear evolution of neo-classical tearing modes, which are excited by these high-order harmonics through providing the seed islands. The aim of this project is to provide the theoretical basis for the passive control and confinement improvement in tokamak H-mode and to develop the large-scale simulation codes with independent intellectual property right.

探索高约束模式（H模）放电是国际上托卡马克物理的研究重心，理解相应的磁流体不稳定性模式的物理机制、并加以反馈控制是实现H模放电的前提基础。本项目拟紧密围绕国内EAST和HL-2A聚变装置上的高参数H模放电实验诊断结果，开展锯齿振荡过程中q=1髙阶谐波（如m/n=2/2和m/n=3/3模）物理特性的大规模数值模拟研究。研究这些q=1髙阶模式激发特性以及对宏观等离子体参数的依赖性，重点研究它们对锯齿崩塌过程中局部破裂和热流损失的影响，并且着重分析它们如何为新经典撕裂模（NTMs）提供种子磁岛以及NTMs非线性演化的物理过程。本项目的完成将为托卡马克H模运行下的主动控制和约束改善提供必要的理论依据，同时可以完善和发展一套具有自主知识产权的大规模数值模拟编码。

探索高约束模式（H模）放电是国际上托卡马克物理的研究重心，理解相应的磁流体不稳定性模式的物理机制、并加以反馈控制是实现H模放电的前提基础。本项目紧密围绕国内EAST和HL-2A聚变装置上的高参数H模放电实验诊断结果，开展锯齿振荡过程中q=1髙阶谐波（如m/n=2/2和m/n=3/3模）物理特性的大规模数值模拟研究。本项目在这些q=1髙阶模式激发特性、对宏观等离子体参数的依赖性以及非线性演化过程方面有重大进展。相关研究工作在国际重要期刊上发表SCI论文8篇。自主开发了的大规模三维磁流体程序 MHD@DLUT code (MDC)，模拟先进位形下新经典撕裂模的工作被 Nuclear Fusion 期刊选为封面文章；也被选入国家自然科学基金委员会的委刊《Science Foundation in China》 2015 年度突出科研成果。该程序在模拟新经典撕裂模方面已经达到了国际主流水平。