Polarized propagation will fail for B field in -z direction
Equation {Ev1v2} in the DevRef becomes singular for e_Bz = -1.
In this case MatrixFlux::computeDeltaMatrix, will have a division by 0.
SImilar computations are in files TransitionMagneticTanh.cpp and TransitionMagneticNevot.cpp.
Before fixing this, provide tests.
Edited by Joachim Wuttke