Development of fixed-gradient full-f gyrokinetic simulations for global ITG turbulent transport

Nakata, Motoki; Idomura, Yasuhiro   

The quantitative evaluation and prediction of the turbulent transport levels are the most important issues in fusion plasma researches. Global delta-f simulations with fixed-temperature gradient and global full-f ones with fixed-input power have been developed separately so far. In this study, for the purpose of systematic comparisons on the transport properties such as the plasma size and the collisionality scalings on the heat diffusivity among these models, a fixed-gradient source model, which can switch the calculation model from full-f to delta-f, is newly implemented to a global full-f gyrokinetic simulation code GT5D. Nonlinear turbulence evolution with averagely fixed profiles has been confirmed successfully. The implemented source model has also been verified by a benchmark test with a local turbulence simulation code GKV, where a good agreement in the transport level is found for the case with asymptotically local limit parameters.