The xplasma software offers a representation standard for plasma MHD equilibria and parameter profiles. Layered over efficient spline interpolation softare pspline, xplasma consists of a two sets of routines:

The "core plasma" consists of a bicubic spline "inverse equilibrium" representation R(rho,chi),Z(rho,chi) and a set of 1d plasma parameter splines including (at least) g and psi to complete the equilibrium field specification. Several options are provided for the specification of "limiter" or "vessel wall" geometry and creation of a "scrape off layer" plasma in the space between the core plasma and the limiter or vessel wall. Mechanisms are available for setting up rectilinear (R,Z) grids that cover both the core plasma and the scrape off layer, over which bicubic Hermite representations of the field and plasma parameters can be built. Then, the xplasma "eq*" interpolation routines can be used to efficiently provide all data needed for such physics modules as RF ray tracers or neutral beam deposition models. Physics modules can operate in (R,Z) or (rho,chi) space as appropriate.