Progress with the full-F continuum edge gyrokinetic code COGENT

COGENT is an Eulerian gyrokinetic code being developed for edge plasma modeling. The code is distinguished by the use of a high-order finite-volume discretization combined with mapped multi-block grid technology. Our recent work is focused on performing hybrid kinetic ion -- fluid electron electrostatic microturbulence simulations in model and realistic divertor geometries. The simulation model describes the ion scale ion temperature gradient (ITG) and resistive drift and ballooning modes as well as neoclassical ion physics effects. The role of X-point geometry is explored by comparing cross-separatrix simulations with counterpart calculations performed in a toroidal annulus geometry. Preliminary results demonstrate formation of an Er-well and a density pedestal in the regime of suppressed turbulence for the case of a model single-null geometry. Rapid progress is concurrently being made toward including electromagnetic effects. The hybrid model has been extended to include low-beta effects, e.g., shear-Alfven waves. Also, a fluid MHD module, which captures finite-beta effects and can take advantage of the field-aligned grid technology, has been added to the suit of COGENT tools.