Clarify that multiple-scattering transport is triggered only if the intended electron step is longer than a skin depth, even in bulk media away from any region boundaries. This improves efficiency, because a multiple-scattering step costs about the same as 3 single-scattering steps (the default skin depth is 3 mean free paths). Below a skin depth, it is more efficient (and more accurate) to use single-scattering.
Clarify that multiple-scattering transport is triggered only if the intended electron step is longer than a skin depth, even in bulk media away from any region boundaries. This improves efficiency, because a multiple-scattering step costs about the same as 3 single-scattering steps (the default skin depth is 3 mean free paths). Below a skin depth, it is more efficient (and more accurate) to use single-scattering.