The CYTRAN module was developed in the early 1980's by S. Tamor as a fast approximation to the cyclotron radiation transport problem in tokamak plasmas, suitable for inclusion in time-dependent transport codes. In principle, it can also be applied to non-axisymmetric plasmas because it approximates the plasma geometry by a series of annular shells with an average magnetic field strength, density and temperature. However, the strong anisotropy of the cyclotron emission and reabsorption coupled with the toroidal gradients in the magnetic field could make the radiation transport stronger in non-axisymmetric plasmas, although this problem apparently has never been studied.

The present version is written in Fortran 90/95, using features that are relatively easy to adapt to different Fortran compilers and to link to other languages.