The GALPROP program (http://galprop.stanford.edu) computes cosmic-ray propagation numerically. To obtain manifestly accurate solutions an explicit method is now available to replace the Crank-Nicolson operator-splitting method. This can be implemented in the public version of GALPROP with the update provided here.
Instructions: replace the four files propel.cc, propel_diagnostics, Galdef.cc and Galdef.h and rebuild the executable.
Add solution_method and solution_convergence to the galdef parameter file. A test GALDEF file with these parameters is galdef_54_reltest09; the diagnostics document the accuracy of the solution.
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