Soft x-ray tomographic reconstruction of Heliotron J plasma for the study of magnetohydrodynamic equilibrium and stability

查看全文 作　　者：S [1]PUROHIT;Y [1,2]SUZUKI;S [1,2]OHDACHI;S [3]YAMAMOTO 机构地区：[1]SOKENDAI, The Graduate University for Advanced Studies, Toki, Gifu 509-5292, Japan;[2]National Institute for Fusion Science, Toki, Gifu 509-5292, Japan;[3]Institute of Advanced Energy, Kyoto University, Gokasho Uji, Kyoto 611-0011, Japan 出　　处：《Plasma Science and Technology》索引2019年第21卷第6期,共7页 摘　　要：The preparation for an experimental soft x-ray tomography study on the Heliotron J (H-J) machine is carried out,with the objectives of evaluating the capability of the current soft x-ray tomographic system in terms of the identification of different mode structures and their poloidal rotation,and the axis shift with different plasma and machine parameters,and fixing the physics goals for the experimental study.These preparations were carried out via a simulated soft x-ray data set arising from different plasma conditions,such as magnetic islands,low beta and high beta.Soft x-ray tomography (SXT) is performed by the discrete pixel method including singular value decomposition and Phillips-Tikhonov regularization,to obtain clear and smooth images.The H-J soft x-ray tomography results from simulated soft x-rays for the equilibrium H-J plasma sensed the magnetic axis shift clearly and an estimate was also achieved.Successful reconstruction for mode structure m =1/n =1 was obtained along with the realization of the poloidal rotation of the structure.The reconstruction for the m =2/n =1 mode was not very clear for the current soft x-ray diagnostic design.Effective mode identification was not possible due to the lack of measurements.The SXT from the current soft x-ray diagnostic on H-J,the magnetic axis shift can be estimated and the m =1/n =1 mode can be studied.Study of higher poloidal modes is difficult with the current design. 关 键 词：HELIOTRON J TOMOGRAPHY SOFT x-ray MAGNETOHYDRODYNAMICS