Study on Confinement of Toroidal Fusion Plasma

在1993 ~ 1995年的3年时间里，共有39名科研人员参加了该项目，其中大部分参加了ASIPP的HT-6 M和NIFS的JIPP T-II U/CHS实验。由于ASIPP HT-6 M托卡马克的主要目标是实现高功率ICRF加热，因此，合作的重点就放在了这一点上。1）1993年，碳限制器的材料被怀疑是加热不良的原因，并被移除。这使得更容易获得更好的ICRF加热靶等离子体。2）关于加载电阻太低的问题，怀疑法拉第屏蔽罩的结构不对，将其拆除，这使得加载电阻变大了一点3）对于墙面调理，4）采用固体靶硼化技术，减少了轻杂质，使等离子体表面加热实验成为可能。5）设计并安装了一个长天线，在HT-1000上进行了等离子体表面加热实验。6M.6）加热方式由二次谐波加热改为2-离子混合加热。这种加热方式的正确选择极大地改善了等离子体加热性能。1996年初，6 M集团能够注入300千瓦的ICRF功率。中子探测器由NIFS提供，每次发射计数300个中子，确保了ICRF加热的高质量。其他活动：参加JIPP T-II U实验的ASIPP研究人员能够在真实的实验中交流关于先进诊断的知识。来自两个研究所的理论家能够介绍他们自己的研究所，并开始使用ASIPP和NIFS计算机进行合作。ASIPP中使用超导线圈的HT-7已经在本学期完成并开始实验。在不久的将来，该设备的合作可能会变得重要。

During 3 years from 1993 to 1995, totally 39 researchers joined this program.Most of them took part in the experiment on HT-6M in ASIPP and JIPP T-II U/CHS in NIFS.Since the major goal of HT-6M tokamak in ASIPP is to demonstrate high power ICRF heating, the emphasis of collaboration was put there.ICRF experiment in HT-6M :1) In 1993, the material of the carbon limiter was suspected to be the reason for poor heating and was removed.It made easier to have better target plasma of ICRF heating.2) With regard to the problem that the loading resistance was too low, the structure of the Faraday shield was suspected to be wrong and it was removed.This made the loading resistance a little larger.3) For wall conditioning, Ti gettering was applied.This made the target plasma further better.4) Solid target boronization was applied.This reduced light impurities and enabled an experiment on plasma surface heating.5) A long antenna was designed and installed in HT-6M.6) Heating regime was changed from second harmonic heating to 2-ion hybrid heating.This proper choice of the heating regime highly improved the plasma heating performance.Through such efforts HT-6M group was able to inject 300 kW of ICRF power in early 1996.Neutron detector was provided from NIFS and counted 300 neutrons per shot assuring the high quality oh the ICRF heating.The ion temperature arose from 150 eV to 550eV as the result of the heating.Other activities :The ASIPP researchers joined in JIPP T-II U experiment were able to excharged knowledge about advanced diagnostics in real experiment.Theorists from both institute were able to introduce their own insitute and collaborative work began mutually using ASIPP and NIFS computers.HT-7 in ASIPP,which uses super conductor coil, has been completed in this term and experiments have begun.Collaboration on this device may become important in the near future.