Electron gun and electron beam application apparatus

An electron gun comprising:

• a photocathode including a substrate and a photoelectric film;
• a light source that emits pulsed excitation light;
• a condenser lens that focuses the pulsed excitation light toward the photocathode;
• and
• an extractor electrode that faces the photocathode and that accelerates an electron beam generated from the photoelectric film by focusing the pulsed excitation light by the condenser lens, transmitting the pulsed excitation light through the substrate of the photocathode, and causing the pulsed excitation light to be incident on the photocathode, wherein
• the pulsed excitation light is condensed at different timings at different positions on the photoelectric film of the photocathode,
• the pulsed excitation light is condensed at a plurality of positions on the photoelectric film of the photocathode at a predetermined cycle, and timings of the pulsed excitation light condensed at the plurality of positions are different from each other,
• the light source includes an angle modulation mechanism that changes an emission angle of the pulsed excitation light, and
• the angle modulation mechanism includes a plurality of laser light sources, a plurality of optical fibers each having one of the plurality of laser light sources provided at a same end thereof, a collimator lens facing the other ends of the plurality of optical fibers, and a pulse power source that drives any one of the plurality of laser light sources.

An electron beam application apparatus comprising:

• a photoexcited electron gun including an excitation light converging optical system and a photocathode, the excitation light converging optical system including a light source and a condenser lens;
• an electron optical system including a deflector that two-dimensionally scans a sample with a pulsed electron beam from the photoexcited electron gun;
• and
• a control unit that controls the excitation light converging optical system to emit the pulsed electron beam from different positions on the photocathode at different timings, wherein
• the control unit outputs a deflection control signal for controlling a trajectory of the pulsed electron beam in synchronization with a control signal for controlling emission of the pulsed electron beam such that the pulsed electron beam emitted from a different position on the photocathode is emitted to the same position on the sample.

An electron beam application apparatus comprising:

• a photoexcited electron gun including an excitation light converging optical system and a photocathode, the excitation light converging optical system including a light source and a condenser lens;
• an electron optical system including a deflector that two-dimensionally scans a sample with a pulsed electron beam from the photoexcited electron gun;
• a detector that detects electrons generated by the sample being irradiated with the pulsed electron beam and that outputs a detection signal;
• and
• a control unit that controls the excitation light converging optical system to emit the pulsed electron beam from a plurality of positions on the photocathode at different timings, wherein
• the control unit outputs a discrimination signal synchronized with a control signal for controlling emission of the pulsed electron beam, and is capable of discriminating, based on the discrimination signal, which position among the plurality of positions on the photocathode the pulsed electron beam is emitted to the sample from, in order to detect the detection signal output from the detector.