Size scaling of turbulent transport in magnetically confined plasmas

The transport scaling with respect to device size in magnetically confined plasmas for electrostatic ion-temperature-gradient turbulence was discussed using global gyrokinetic particle simulations. It was observed that by varying device size normalized by ion gyroradius, while other dimensionless plasma paramter were fixed, the fluctuation scale strength was microscopic in the presence of zonal flows. The analysis showed that the local transport coefficient exihibits a gradual transition from Bohm-like scaling for device sizes which corresponded to present day experiment to a gyro-Bohm scaling for future larger devices.