ITER-like 플라즈마에서의 불순물 분포와 수송 상수 결정에 대한 연구

Abstract

Monitoring impurity behaviors is extremely important to sustain the burning plasmas such as ITER. Accumulation of the impurities in the core may induce radiation cooling in the core of the plasma and energy balance at the divertor region is dominated by impurity distribution at the edge of the plasma. Impurities in burning plasmas consist of two branches: dominant species are from the first wall material such as Carbon (C), Tungsten (W), Iron (Fe) through erosion process

the other species are from externally injected materials for diagnostics and operational purpose. An impurity transport simulation code, Multiple Ionization State Transport (MIST), which is designed for circular cross-section plasma, has been used to study the radial distribution of impurities in various charge states in ITER-like plasma parameters. Assuming symmetry in all but the radial direction (cylindrical geometry), the plasma has been divided into 50 radial zones from the plasma center to the scrape off layer. Radial plasma profiles of electron and ion temperature, electron and ion density, and safety factor are used in this study. Study of impurity distribution has been investigated in both time independent (steady-state) and time-dependent cases. Here, the impurity profiles include charge state density, effective atomic number, local and total radiation power, line emission and brightness for variety possible impurity species, etc. Furthermore, in time independent case the impurity transport coefficients have been determined by comparing the code results with other calculated results of radiation power profile.