Study on Confinement of Toroidal Fusion Plasma

从1993年到1995年的3年间，共有39名研究人员参加了这项计划。他们中的大多数人参加了ASIPP的HT-6M和NIF的JIPP T-II U/CHS的实验。由于ASIPP的HT-6M托卡马克的主要目标是演示高功率ICRF加热，所以重点放在了合作上。HT6M的ICRF实验：1)1993年，由于怀疑碳限幅器的材料是加热不良的原因，因此去掉了它，使得更容易获得更好的ICRF加热的靶等离子体。2)针对负载阻力太低的问题，法拉第屏蔽的结构被怀疑是错误的，并将其移除。这使得负载阻力略大。3)对于墙的调节，4)采用固体靶渗硼，减少了光杂质，实现了等离子体表面加热实验。5)在HT-6M上设计并安装了长天线。6)加热方式由二次谐波加热改变为2-离子混合加热。加热方式的合理选择极大地提高了等离子体的加热性能。通过这样的努力，HT-6M组于1996年初能够注入300kW的ICRF功率。由NIFS提供的中子探测器，每一次计数300个中子，确保了ICRF加热的高质量。由于加热的结果，离子温度从150 eV上升到550 eV。其他活动：参加JIPP T-II U实验的ASIPP研究人员能够在真实实验中传授高级诊断知识。两个研究所的理论工作者都能够介绍他们自己的设备，并开始相互使用ASIPP和NIFS计算机进行协作工作。ASIPP中的HT-7，它使用超导线圈，已经在本学期完成，实验已经开始。在不久的将来，在这个设备上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.