Method and device for rastering source redundancy

A charged particle beam source for emitting a plurality of charged particle beams, comprising:

• a plurality of emitting units, each emitting unit comprises a memory unit and at least an emitter for emitting a charged particle beam, wherein information stored in the memory unit is used to control the emitter;
• and
• a shift circuit which is used to shift the information stored in the memory unit of a first emitting unit to at least the memory unit of a further emitting unit which is different from the first emitting unit.

A data feed system for a charged particle source array, comprising

• a data path for storing information and providing first group of emitting units (106, 202) with information;
• at least one shift circuit (140) for shifting the information from at least one emitting unit of the first group of emitting units to at least a further emitting unit;
• wherein each emitting unit comprises a memory unit and at least an emitter for emitting a charge particle beam, and wherein the information is stored in the memory unit for controlling the emitter.