3-D NUMIT: A General 3-D Internal Charging Code

A general 3-D internal charge analysis method, 3-D NUMIT, was developed by combining a Monte Carlo radiation transport simulation tool such as MCNPX or GEANT4 and a commercial finite-element analysis software such as COMSOL. The method was validated in 1-D cases with the analytical solution and NUMIT 2.0 and in a 3-D case with previously developed CB_IESD. The internal charging behavior of a semi-rigid coax cable in space was successfully analyzed using this 3-D NUMIT method.