Effects of Neutral Particles on the Stability of the Detachment Fronts in Divertor Plasmas

Operation with detached divertor plasmas is considered to be a hopeful way in order to reduce the divertor heat load in the next generation tokamaks. The physical mechanism of detached divertor plasmas, however, has not fully been understood yet. We have studied them with a one-dimensional divertor model. Detached divertor plasmas have been successfully reproduced by introducing a self-consistent neutral model. The flows of particles and heat from the core plasma were investigated in the detached regime. Also investigated were the conditions of the recycling rate and neutral loss time constant where the detached regime occurred.