Electron gun, electron beam applicator, and emission method of electron beam

An emission method of an electron beam,

• wherein the electron beam is emitted from an electron gun including
• a light source,
• a photocathode configured to generate releasable electrons in response to receiving light from the light source,
• an anode configured to generate an electric field between the photocathode and the anode, extract the releasable electrons by the generated electric field, and form an electron beam, and
• a control unit, and
• wherein the control unit is configured to
• set the number of emission times of the electron beam and set an electron beam parameter for each emitting electron beam, or
• set an emission duration of the electron beam and set an electron beam parameter of an emitting electron beam in association with the emission duration,
• the emission method comprising:
• an electron beam emission step of forming an electron beam by irradiating the photocathode with excitation light from the light source and extracting releasable electrons generated by the photocathode in response to receiving the excitation light by using an electric field generated between the photocathode and the anode,
• wherein control unit performs control in the electron beam emission step such that an emitting electron beam has the set electron beam parameter.