Optimization of support grid for extraction window in electron accelerator

A system for the beam raster-scanning is used in the accelerator. To reduce the beam losses, a support grid with wedge-shaped ribs of varying tilt angles is used. The GEANT4 code was applied to simulate the transmission of electrons through the grid and the foil supported by the grid. The total energy losses for different rib geometry have been evaluated, and the non-uniformity of the foil thermal load has been studied.