Criteria and principles of optimization of concentrating electron-optical systems

Approach to optimization of concentrating electron-optical systems (EOS), forming beams of ''electron probe'' type is suggested. Such beams are widely used for electron-beam welding, thermal cutting and electron-beam surface modification of materials. Main purposes,pursued when designing and optimizing technological EOS for these processes, lie in achieving the maximal electron luminosity and length of a region (active region), where power density exceeds the certain critical value