COMPREHENSIVE STUDY OF TOROIDAL FUSION SYSTEM

这项为期三年的计划主要围绕以下四个对核聚变研究具有重要意义的课题展开：(1)开发基于回转动力学粒子模型的模拟程序，以研究磁约束等离子体的行为。(2)美国国家核聚变科学研究所正在研制的大型螺旋装置(LHD)用微波反射计。(3)基于NIFS的JIPP T-IIU和加州大学洛杉矶分校的CCT的实验结果，提出了改善LHD约束的情景。(4)基于螺旋系统的聚变堆的概念设计。(1)由美国国立卫生研究院和加州大学洛杉矶分校物理系合作开发了一个三维陀螺运动粒子程序。实践证明，该模拟程序适用于与MHD模式相关的等离子体运动的研究。使用该代码可以模拟内扭结模式的稳定化以及去稳定化…由于高能离子的存在，阿尔芬波被激发得更多。该程序可以解释当磁轴上的安全值Q小于1时，由于磁场重联而产生的磁岛的生长和等离子体在磁轴上的相关损失。(2)微波反射仪是测量等离子体中电子密度分布和密度涨落的有力手段。使用X模作为反射计的一个优点是能够测量低密度区域，例如分界线外的区域，这被认为与H模跃迁和离子回旋加热实验有很强的联系。讨论了DIII-D托卡马克装置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和相关问题。(3)将加州大学洛杉矶分校发展的渗硼方法应用于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为该方法在LHD等离子体约束改善中的应用奠定了基础。(4)在加州大学洛杉矶分校等离子体与聚变研究中心开展了基于托卡马克系统的核聚变反应堆的概念设计。通过与加州大学洛杉矶分校相关科学家的讨论，推动了基于螺旋系统的反应堆设计。较少

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