Extension of IMPMC code toward time evolution simulation

A self-consistent modelling of divertor plasma and impurity transport has been developed. The key feature of this integrated code, SONIC, is to incorporate the elaborate impurity Monte Carlo code, IMPMC, Monte-Carlo (MC) approach is suitable for modelling of interactions between impurities and walls, including kinetic effects, and the complicated dissociation process of hydrocarbons. The MC modelling, however, has the disadvantage for long computational time, large MC noise, and assumption of steady state. The first and second difficulties were solved by developing a new diffusion model and optimizing with a Message Passing Interface (MPI) on the massive parallel computer. The third subject is solved by extension of IMPMC code toward time evolution simulation. A time-dependent simulation with impurity MC code involves a problem to increase number of test particles. The particle reduction method to resolve this problem is newly developed and validated. (author)