Development of Fusion Plasma Confinement in Helical Systems

与托卡马克型装置相比，螺旋聚变系统具有无等离子体电流中断和稳定可靠的稳态运行等优点。为了实现更好的聚变反应堆，发展螺旋聚变系统的等离子体约束是非常重要的。目前，日本的LHD（大型螺旋装置）正在建设中，（紧凑型螺旋系统）正在运行。另一方面，在德国，W7-X（Wendelstein 7-X）项目已获批准，W7-AS实验正在进行中。这两个项目的相互讨论是非常有用的。几位日本科学家访问了IPP-Garching，讨论了以下项目：（1）LHD方案与W7-X方案的比较对两个方案中的等离子体约束概念进行了比较和校核，并对两个方案中的超导线圈导体进行了比较。(2)对CHS和W7-AS的实验结果进行了比较，并对约束模型进行了检验。(3)螺旋系统的一般约束理论对螺旋约束理论进行了个人交流。此外，几位科学家访问了德国和西班牙，了解德国仿星器和西班牙TJ-II太阳能项目的情况，并讨论了未来的研究合作计划。在下一个财政年度，这些合作研究应作为文部省国际科学研究计划的资助项目加速进行。

Helical fusion systems have major advantages over Tokamak-type devices because of no plasma current disruptions and reliable steady-state operations.For achieving better fusion reactors, it is important to develop the plasma confinement of helical systems.At present in Japan, the LHD (Large Helical Device) is under construction, and the CHS (Compact Helical System) is in operation.On the other hand, In Germany, the W7-X (Wendelstein7-X) project has been approved and the W7-AS experiments are being carried out.It is very useful to discussed with each other for both projects.Several Japanese scientists visited IPP-Garching to discuss the following items :(1) Comparisons between LHD Project and W7-X PlanningThe concepts of plasma confinements in both projects are compared and checked.Moreover, superconducting coil conductors for both projects are compared.(2) Comparisons between CHS and W7-AS experimentsExperimental data from two devices are discussed, and the confinement models are checked.(3) General confinement theory for helical systemsPersonal exchanges have been carried out for helical confinement theory.Moreover, several scientists visited Germany and Spain for getting information on the German stellarators and the Spanish TJ-II heliac project, as well as to discuss on the future research collaboration plan.In the next fiscal year, these collaboration researches should accelerated as a Grant under the Monbusho International Scientific Research Programs.