XGC Documentation



Code Coupling



Documentation by

   Glenn Bateman



   Seung-Hoe Ku



   Julian Cummings



   Choong-Seock Chang



   Arnold Kritz




XGC is a gyrokinetic Particle-in-Cell code designed to model the development of an edge pedestal in the radial density and temperature profiles of tokamak fusion plasmas.  The code also computes scrape-off and wall loss physics. In XGC, the gyrokinetic plasma ion and electron guiding centers evolve in time within a five-dimensional phase space using a realistic magnetic equilibrium and limiter geometry.  The code uses cylindrical coordinates so that the separatrix and X-point region can be easily included in the simulation domain.  It handles charged particle and neutral collisions using a Monte Carlo approach and a simple model source for neutrals at the wall. 

The original code, XGC0, is an axisymmetric ion code that is primarily designed to investigate neoclassical effects during the formation and evolution of the H-mode pedestal. The XGC0 code computes the time evolution of plasma profiles and the radial electric field.  The code presently contains a simple diffusion model for plasma turbulence.

A new 3-D code, XGC1 is being developed to investigate electrostatic turbulence as well as neoclassical effects self-consistently at the edge of the plasma.  Models for electron kinetics are being implemented in the XGC1 code together with a general electric field solver.  Work is in progress on a more sophisticated treatment of neutrals using the DEGAS-2 code.

The XGC code will be coupled with the nonlinear MHD instability codes M3D and NIMROD in order to simulate Edge Localized Mode (ELM) crashes.  The XGC-1 code is being developed by the Center for Plasma Edge Simulations (CPES) SciDAC project.