Electron source

An electron gun including:

• an electron multiplier having a receiving end for receiving primary electrons and an output end that emits secondary electrons responsive to primary electrons arriving at the receiving end;
• an electron emitter arranged at the receiving end of the electron multiplier for supplying primary electrons thereto;
• and
• at least one of an electrical and a magnetic focusing component arranged at the open output end of the electron multiplier for focusing the secondary electrons to define an electron beam.

A method for producing an electron beam, the method including:

• generating first electrons at an apex region;
• repeatedly accelerating electrons toward secondary electron-generating impacts with one or more high secondary electron yield surfaces arranged at increasing distances away from the apex region, the repeated accelerating driving electrons away from the apex region between successive electron-generating impacts, the repeated accelerating terminating when the electrons reach an output region;
• and
• electrically or magnetically biasing electrons in the output region to form an electron beam.