An electron beam apparatus addresses blanking issues resulting from sinking high-power heat onto an aperture diaphragm by evenly spreading heat on the aperture diaphragm. The apparatus can include an aperture diaphragm and a deflector that deflects the electron beam on the aperture diaphragm. The electron beam is directed at the aperture diaphragm in a pattern around the aperture. The pattern may be a circle, square, or polygon. The pattern also may include a variable locus relative to the aperture.