Recent development of GEM-X: an efficient global gyrokinetic simulation of the tokamak edge including the scrape-off layer (SOL)

Development is underway of GEM-X - a fast-time-to-solution gyrokinetic particle code for modeling the edge pedestal, including the SOL region. GEM-X has a full-f option, but then the code will have no advantage over the existing full-f codes. Equilibrium profiles in GEM-X are in a cylindrical R-Z rectangular mesh, which can be generated from other equilibrium codes, such as EFIT and SOLPS-ITER. The 2D electrical static field is going to be calculated in GEM-X 2D mode, with either fluid electron or adiabatic electron response. By changing the size of the simulating electric static potential mask in the rectangular mesh, GEM-X can simulate the core region or the entire tokamak region including SOL. We will show some results from GEM-X in the past year's development.