TY - JOUR T1 - Gyrofluid Simulation of Ion-Scale Turbulence in Tokamak Plasmas JO - Communications in Computational Physics VL - 5 SP - 1245 EP - 1257 PY - 2008 DA - 2008/11 SN - 4 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/cicp/7836.html KW - AB -

An improved three-field gyrofluid model is proposed to numerically simulate ion-scale turbulence in tokamak plasmas, which includes the nonlinear evolution of perturbed electrostatic potential, parallel ion velocity and ion pressure with adiabatic electron response. It is benchmarked through advancing a gyrofluid toroidal global (GFT_G) code as well as the local version (GFT_L), with the emphasis of the collisionless damping of zonal flows. The nonlinear equations are solved by using Fourier decomposition in poloidal and toroidal directions and semi-implicit finite difference method along radial direction. The numerical implementation is briefly explained, especially on the periodic boundary condition in GFT_L version. As a numerical test and also practical application, the nonlinear excitation of geodesic acoustic mode (GAM), as well as its radial structure, is investigated in tokamak plasma turbulence.