Analysis of pedestal characteristics in JT-60U H-mode plasmas based on Monte-Carlo neutral transport simulation

Nakashima, Yosuke*; Higashizono, Yuta*; Kawano, Hirokazu*; Takenaga, Hidenobu; Asakura, Nobuyuki; Oyama, Naoyuki; Kamada, Yutaka

This paper describes the results of pedestal characteristics in H-mode plasmas of JT-60U based on neutral transport simulation using the DEGAS Monte-Carlo code. A three-dimensional (3-D) mesh structure including isolated dome, baffle and divertor plates is precisely built-up and the simulation space is extended from SOL to core plasma region. In this simulation background plasma parameters and the intensity of particle flux on the divertor plates are determined from the UEDGE plasma code. The dependence of plasma density on the neutral penetration and ionization area were investigated in two cases of ELMy H-mode discharge with gas puffing and without gas puffing. The simulation results showed noticeable differences in 1/e scale length in the neutral penetration and in ionization width near edge transport barrier region. Dependence of the plasma density from the pedestal edge to SOL region on the ionization region and the 3-D effect of local gas puffing are discussed in terms of neutral transport.