CASK

The underlying basis of CASK is the mapping of a physical region onto a logical quadrilateral grid that represents the computational domain. The non-orthogonal mesh used in CASK is found by an elliptical solver used to generate the mapping of the logical grid to conformally fit the physical boundaries of the simulation domain. A set of high level subroutines has been written to numerically compute the gradient of mesh wide scalars, as well as the divergence and curl operators for mesh wide vector fields. The operators are correct to second order in the local mesh spacing. The algorithm selected for computing these operators contains a set of differencing coefficients to enable accurate numerical results on highly non-orthogonal curvilinear grids. The code contains both electrostatic and electromagnetic field solvers and particle orbit integration subroutines for plasma simulation. An efficient method has been developed to determine the cell location of particles on the mesh. The code has been used to find eigenmodes of cavities in the frequency domain; for transient electromagnetic problems; for intense electron beam injector design; and for simulation of a charge collecting biased probe immersed in a plasma. Representative results from these simulations are presented as well as details of the code structure and numerical algorithms employed