Confinement of Currentless Steady State Plasma in Helical Type ATF Device

与ORNL联合开展了无电流稳态等离子体在ATF中的约束研究，以获得有关等离子体约束、稳定性、粒子控制和等离子体-壁相互作用的数据库，为未来螺旋聚变反应堆的设计提供依据。日本研制了用于35.5 GHz微波传输的部分元器件，并提供给ATF实验。1991年，NIFS的两名研究人员访问了ORNL，参加了在ATF进行的长时间ECH排放实验。另一个人在1992年访问了ORNL，讨论了ATF的结果，并调查了ATF的状况和未来的实验计划。ORNL的两名研究人员被邀请到NIF结束目前的计划，并延长对稳态等离子体的合作研究。1991年5月30日，螺旋线圈的损坏导致ATF的操作受到限制。利用35 GHz微波，在0.63T场强下，成功地实现了高达20秒的二次谐波ECH。6秒放电时的等离子体参数为：线平均电子密度2x10；m；-3；电子温度700 eV。未观察到杂质积累，损坏的螺旋线圈已完全修复。然而，重新启动的时间表并不有利于目前的计划。这项研究已于1993年2月在日本研究人员和从ORNL邀请的ATF实验协调员村上博士之间完成。我们已经为数据库的建设和访问安排了计算机网络。与受邀的里昂博士讨论了更多加强合作的问题，里昂博士是ORNL的恒星定位器项目协调员。我们准备开始合作，不仅是在ATF，而且在CHS和LHD项目上(1)开发更有效的ICRF加热，(2)高功率Ech的经验，(3)改进偏滤器几何结构的开发，(4)远程数据获取及其分析的经验，以及(5)螺旋聚变反应堆及其优化研究。

The joint research with ORNL on confinement of currentless steady state plasma in ATF was started to obtain a database on plasma confinement, stability, particle control and plasma-wall interaction for a future design of helical fusion reactors. Some components for 35.5 GHz microwave transmission were manufactured and provided for the ATF experiment by Japan. Two researchers at NIFS visited ORNL in 1991 to join the long ECH discharge experiment in ATF. Another one visited ORNL in 1992 to discuss the ATF results and investigate the status of ATF and a future experimental plan. Two researchers at ORNL were invited to NIFS to conclude the present program and extend the collaborative study on a steady state plasma.A damage in the helical coil on May 30, 1991, caused a restricted operation of ATF. The second harmonic ECH by 35GHz microwave at 0.63T field was successfully demonstrated up to 20 seconds. The plasma parameters at a 6-seconds discharge are ; the line-averaged electron density 2x10^<18>m^<-3> ; the stored kinetic energy 500j ; and the electron temperature 700eV. No impurity accumulation was observed.The damaged helical coil has been fully repaired. The restart schedule is, however, not in favor of the present program. The study has been concluded in February, 1993 among the Japanese investigators and Dr. Murakami, the ATF experimental coordinator, invited from ORNL. We have arranged the computer network for construction of and access to the database. More enhanced collaboration was discussed with invited Dr. Lyon, the stellarator project coordinator in ORNL. We are ready to start the collaboration not only in ATF but also in CHS and LHD project on (1)development of more effective ICRF heating, (2)experience with high-power'ECH, (3)development of an improved divertor geometry; (4)experience with remote taking of data and its analysis; and (5)helical fusion reactor and its optimization study.