Sensitivity Check of Background Plasma Parameter during SMBI in the GAMMA 10 Central-Cell by 3-D Monte-Carlo Simulations

Abstract

The gas fueling by supersonic molecular beam injection (SMBI) has been carried out in the world largest tandem mirror device GAMMA 10 and higher plasma density has been achieved compared with conventional gas-puffing. Three-dimensional Monte-Carlo code DEGAS is applied to GAMMA 10 and the spatial distribution of neutral particle density during SMBI is investigated. σ_div is introduced as divergence angle index of the initial particle to simulate the molecular beam injected by SMBI. It is defined to be unity in the case of cosine distribution of the angular profile of launched particles. It is found that the particles are suppressed and localized in the injection point according to the reduction of divergence angle index, σ_div and well explained the GAMMA 10 SMBI experimental results at divergence angle index, σ_div = 0.33. In this paper the simulation is carried out in the different profiles of electron temperature in order to check the sensitivity of the background plasma parameter. The simulation results indicate that the penetration depth depended on the background plasma parameter, electron temperature.