Geant4 and Fano cavity test: where are we?

The electron transport algorithm implemented in Geant4 has been recently revised. The modifications concern several physics aspects of the simulation model: the step limitation, the energy loss along a step and the multiple scattering. The Fano cavity setup was used to test these developments. The upgrades increase significantly the accuracy of the electron transport simulation. The ratio of simulated to theoretical dose deposition in the cavity is stable to ∼1% while varying several parameters and within ∼1.5% of the expected value for water and graphite. Work is underway to identify and resolve the remaining shift.