APPARATUS FOR MODULATING A PARTICLE BEAM INTENSITY

摘要

An apparatus for pulsing an electron beam essentially includes two pulse generators driven by a synchronizing unit, an electronic time delay element for delaying a trigger signal generated by the synchronizing unit, and two blanking capacitors arranged between the electron source and a first condensor lens and an electron optical column of an electron beam metrological equipment. Signals of different frequencies are applied to the blanking capacitors so that one electron pulse reaches the module surface per period t of the signal being measured. The phase relationship of the electron pulses is shifted over a time range of interest with the assistance of a controllable time delay element.