COMPREHENSIVE STUDY OF TOROIDAL FUSION SYSTEM

本项目为期3年，主要开展了以下4个对核聚变研究具有迫切意义的课题：(1)开发基于陀螺动力学粒子模型的模拟程序，用于研究磁约束等离子体的行为。(2)正在国家聚变科学研究所（NIFS）建设的大型螺旋装置（LHD）微波反射计的研制。(3)基于NIFS JIPP T-IIU和UCLA CCT实验结果的LHD约束改进方案。(4)基于螺旋系统的核聚变反应堆概念设计。(1) NIFS与UCLA物理系合作开发了三维陀螺动力学粒子代码。实验证明，该仿真程序适用于与MHD模式相关的等离子体运动研究。利用此代码可以模拟内部扭结模式的稳定化以及高能量离子存在下的阿尔芬波的不稳定性。该代码可以解释磁场重联产生磁岛的过程，以及磁轴上的安全值q小于1时磁轴上等离子体的相关损耗。(2)微波反射计是测量等离子体中电子密度分布和密度波动的有力手段。使用x模式作为反射计的优点是能够测量低密度区域，如分离矩阵外，这被认为与h模式跃迁和离子回旋加速器加热实验有很强的联系。讨论了DIII-D托卡马克在加州大学洛杉矶分校电气工程系和通用原子公司的适用性及相关问题。(3)将UCLA开发并转移到NIFS的硼化方法应用于NIFS JIPP T-IIU和CHS真空室的内表面处理。边缘等离子体和表面等离子体相互作用的控制有望将该方法应用于LHD等离子体约束的改进。(4)在加州大学洛杉矶分校等离子体与聚变研究中心进行了基于托卡马克系统的核聚变反应堆概念设计。基于螺旋系统的反应堆设计是通过与加州大学洛杉矶分校相关科学家的讨论而得到推广的。少

The 3-year program has been carried out on the following four subjects which are urgently important for the nuclear fusion research : (1) Development of simulation codes based on the gyro-kinetic particle model, for the purpose of investigating the behavior of a magnetically confined plasma. (2) Development of microwave reflectometer for Large Helical Device (LHD) which is under construction at the National Institute for Fusion Science (NIFS). (3) Scenarios for confinement improvement on LHD, based on the experimental results of JIPP T-IIU at NIFS and CCT at UCLA. (4) Conceptual design of a fusion reactor based on helical system.(1) A three dimensional gyro-kinetic particle code has been developed by the collaborative work between NIFS and Physics Department of UCLA. It has been proved that this simulation code is applicable to the study of plasma motions related with MHD modes. It becomes possible with this code to simulate the stabilization of internal kink mode as well as destabiliz … More ation of Alfven waves by the presence of high energy ions. The code can explain the growth of magnetic islands by magnetic field reconnection and the related loss of plasma on the magnetic axis when the safety value q on the axis is made lower than 1.(2) The microwave reflectometer is a powerful means to measure the electron density profile as well as density fluctuations in a plasma. The use of X-mode for the reflectometer has an advantage of being able to measure the low density region such as outside of a separatrix, which is believed to have a strong connection with H-mode transition and ion cyclotron heating experiments. The applicability and related problems are discussed at Electric Engineering Department of UCLA and General Atomics where the DIII-D tokamak is under operation.(3) The boronization method which has been developed at UCLA and transferred to NIFS has been applied to the inner surface treatment of vacuum chambers of JIPP T-IIU and CHS at NIFS. The control of edge plasma and surface plasma interaction is found promising to the application of this method to LHD plasma confinement improvement.(4) A conceptual design of nuclear fusion reactor based on the tokamak system has been carried out at Plasma and Fusion Research Center of UCLA. The reactor design based on the helical system has been promoted by the discussion with related scientists at UCLA. Less