On the accuracy and efficiency of condensed history transport in magnetic fields in GEANT4.The purpose of this work was to investigate the accuracy and efficiency of electron transport in GEANT4 with and without a magnetic field present.  Fano cavity simulations were performed in GEANT4 version 10.02 and 10.04.p01 using two multiple scattering (MSC) algorithms for two slab and one pseudo-ion chamber geometries.  Similar to previous works, the step lengths had to be severely restricted to obtain agreement with theory when using the Urban MSC model in GEANT4 v10.02.  Using the Goudsmit-Saunderson MSC model with the UseSafetyPlus MSC step limitation in GEANT4 v10.04.p01 limited the maximum discrepancy from theory to 0.5%.  Agreement with theory in the absence of a magnetic field can be obtained without significantly restricting the step size if the Goudsmit-Saunderson MSC model is used with the UseSafetyPlus MSC step limitation in GEANT4 v10.04.p01.  This work has shown that GEANT4 can perform accurate electron transport with and without a magnetic field present without applying significant step-size reductions.
GEANT4