4. Neoclassical and Turbulent Transport Simulation Group

We promote the gyro-kinetic, drift-kinetic and/or fluid model simulation studies on turbulent and neoclassical transport in magnetically confined plasmas such as LHD. Main research objectives are evaluation of transport properties in LHD experiments, understandings of the transport mechanisms, validation of the simulation results toward prediction, and R&D of the simulation codes. We also grapple with modeling of transport coefficients for reinforcing an integrated transport code, using analyses of simulation data.

Gyrokinetic simulation of the ion temperature gradient turbulence and zonal flows in LHD plasma.
Time-evolutions of the neoclassical ion particle flux (left) and the radial electric field (right) in LHD plasma. The radial electric field is spontaneously formed so that the ion and electron fluxes balance with each other. In the case shown here, the electric field transition from negative to positive observed in 0.2 < r < 0.6 with neoclassical transport reduction leads to improvement of the plasma confinement.

Poincare map of electrostatic potential profile and magnetic field derived from the reduced two-fluid simulation in toroidal plasmas. The turbulent states are shown before (t=245) and after (t=324) the macroscopic magnetic island appears.