JSOLVER is a fixed-boundary, toroidal MHD equilibrium code, which
solves the Grad-Shafranov equation for the poloidal flux using
a finite difference scheme. JSOLVER applies an iterative metric
method to simultaneously solve for the plasma equilibrium and the
magnetic in flux in equal-arc coordinates.
JSOLVER requires as input the plasma-vacuum boundary plus two radial profiles (the pressure or its derivative and the flux averaged parallel current density). The code can be run in two ways; the plasma-vacuum boundary and the profiles are supplied a set of data points or can be specified in the "inequ" file. The latter option corresponds to the 'old' way of running the code. JSOLVER can also read the output file "eqdsa.cdf" by setting ifunc2=4 in "inequ". The "eqdsa.cdf" file can be produced from the binary output file "eqdska" of the TSC code using the tsc2cdf tool (also supplied in this distribution).
The ouput profiles and metric can be saved in the NetCDF file eqdsk.cdf. This file contains all (as well as some redundant) information about the equilibrium for postprecessing. Global variables can also be accessed through GET calls, a perhaps more convenient way to extract data from the code. Output data include the pressure, the safety factor, the covariant toroidal B function, the mesh coordinates (R,Z) as function of the flux and poloidal angle, and the Jacobian at the mesh nodes and in between.