Three-dimensional neutral transport simulation in the JT-60U H-mode plasmas

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

The first results of a fully three-dimensional (3-D) Monte-Carlo simulation using DEGAS ver.63 code applied to the JT-60U tokamak and analysis of neutral behavior in H-mode plasmas are described. A precise mesh structure including isolated dome, baffle and divertor plates is built-up and the simulation space is extended from SOL/divertor to core plasma region. Benchmarking with 2-dimensional simulation with the DEGAS2 code successfully showed the validity of the present simulation. Result of 3-D simulation in the JT-60U plasma with gas puffing indicates the significant localization of neutrals around the gas puffer and the detail of neutral diffusion in toroidal and poloidal directions are clarified. The dependence of plasma density on the neutral penetration and ionization area are also discussed in different H-mode discharges.