报告人: Prof. Motoshi Goto (NIFS)

　　时间：2025年1月2日 9:30-10:30

　　地点：8-1二楼会议室

　　主持人：明廷凤

　　报告摘要: Four topics from recent LHD research will be presented. To study the energy level structure of tungsten ions, research is ongoing to identify emission lines by obtaining emission spectra through tungsten pellet injection and spectroscopic measurements, and comparing the results with simulations. Recently, progress has been made in understanding the spectra of ions with 22+ to 24+, and the results of experiments and simulations are now in good agreement. For the Thomson scattering measurements, improvements in the laser system have made it possible to measure with a high time resolution of 200 kHz. For example, it has become possible to study in detail the time evolution of the spatial distribution of electron temperature and density during the injection of hydrogen pellets. The high-speed charge-exchange spectroscopy has been used to successfully measure the distortion of the velocity distribution function of ions associated with MHD bursts. This phenomenon is understood to be a direct observation of Landau damping. The anisotropy of the electron velocity distribution is investigated by polarization spectroscopy. The difference in electron temperature in the directions parallel and perpendicular to the magnetic field has been inferred from the measured polarization of the Lyman-α hydrogen atom radiation.