ESN: One-dimensional Sn transport module for electrons

ESN is a time-dependent, one-dimensional Lagrangian transport code that solves the electron multigroup, discrete ordinates transport equations with electromagnetic fields. An exponential spatial differencing scheme based upon inversion of the homogeneous transport equation is employed with the diamond approximation in angle. Energy transfers are allowed between adjacent groups (continuous approximation). Sources of any functional form are permissible. Scattering and slowing down are treated in the Fokker-Planck representation. Electromagnetic fields enter the equations through E, v×B Lorentz terms and are treated as effective collisional sources. Transport cross sections are also generated by the module. We describe the methods and modifications used to track electrons in the S_n representation and present results and comparisons using ESN.