NEUTRAL TRANSPORT ANALYSIS IN PLASMA EDGE REGION OF THE GAMMA-10 CENTRAL-CELL

Based on the results of neutral transport simulation using cylindrical mesh-model, the effect of the plasma edge region was investigated in the GAMMA 10 central-cell. 3-dimensional geometry and neutral sources such as gas puffers, limiters, and neutral beam injection are precisely constructed in the mesh-model of the GAMMA 10 central-cell. From the neutral transport simulation in the case of each neutral source, 1/e decay lengths of H alpha-line intensity (H alpha decay length) along with z-axis were evaluated. It was found that H alpha-line intensity calculated by the simulation of the gas puffer #3(GP#3) in mirror-throat region takes a broader profile than that of central-limiter and gas puffer #7(GP#7) around the central midplane region because the plasma density is low in mirror-throat and the neutral particles are given near the vacuum vessel, while the neutral particles in the central-limiter are given near the plasma core. The simulation results also revealed that the H alpha-line intensity drastically decrease in the range with interior components. On the other hand, it was clarified that the H alpha-line intensity in no interior component area takes a little reduction because of a large width in plasma edge region.