Edge Plasma. Physics

点击翻译按钮获取中文摘要

# Detached plasma with electron-ion recombinationIncomplete thermalization of singlet and triplet high n-levels results in a different response to diffusion processes under edge plasma conditions, especially for detached plasma with electron-ion recombination. The collisional-radiative numerical code SOPHIA shows that intercombination transitions and radiation transport effects are extremely important to describe the line emission whereas inequilibrium plasmas, these transitions give only little corrections. We have shown that the intensity of transitions originating from the singlet and triplet system strongly depends on diffusion.# Fluctuation propertyin attached and detached plasmas and related non-local transport phenomena We have investigated the velocity distribution of the intermittent bursty fluctuations in the ion saturation currents observed in the linear divertor plasma simulator, NAGDIS-II. The intermittent bursty signals were analyzed by the wavelet transform with complex … More Morlet mother wavelet. Analyzing a lot of bursts in the ion saturation currents based on the wavelet cross-correlation gives the velocity distribution function. It is positively skewed at the peripheral region of the plasma column, which means the intermittent bursts mainly propagate toward the wall. The averaged velocity depends on the neutral pressure associated with the transition between the attached and detached plasmas.# Influence of dynamic ergodic divertor on fluctuation and transport properties in tokamak plasmasWe have conducted the experiment to investigate microscopic plasma response to rotating helical magnetic filed by using an electrostatic probe with multi pins. Correlation between time evolution of ion saturation currents measured with each probe was analyzed by wavelet analysis, which has strong advantage for analyzing time evolution data with intermittent events. At wavelet-scale corresponding to the driving frequency of DED (dynamic ergodic divertor), intermittent turbulence of plasma density was observed. It is also found that the turbulence structure propagates in the same direction of rotation of helical magnetic filed. This phenomena could be related to chaos control. Less