Editing Electron gun (section)

{{Short description|Electrical component producing a narrow electron beam}}
{{Refimprove|date=March 2020}}
[[file:Egun.jpg|thumb|Electron gun from a [[cathode-ray tube]]]]
[[file:Vidicon Electron Gun.jpg|thumb|The electron gun from an [[RCA]] [[Vidicon]] [[video camera tube]]]]

An '''electron gun''' (also called '''electron emitter''') is an electrical component in some [[vacuum tube]]s that produces a narrow, [[collimation|collimated]] [[electron beam]] that has a precise [[kinetic energy]].

The largest use is in [[cathode-ray tube]]s (CRTs), used in older [[television set]]s, [[computer display]]s and [[oscilloscope]]s, before the advent of [[flat-panel displays]]. Electron guns are also used in [[field-emission display|field-emission displays (FEDs)]], which are essentially flat-panel displays made out of rows of extremely small cathode-ray tubes. They are also used in microwave linear beam [[vacuum tube]]s such as [[klystron]]s, [[inductive output tube]]s, [[travelling-wave tube]]s, and [[gyrotron]]s, as well as in scientific instruments such as [[electron microscope]]s and [[particle accelerators]].

Electron guns may be classified by the type of electric field generation (DC or RF), by emission mechanism ([[thermionic emission|thermionic]],  [[photocathode]], [[field electron emission|cold emission]], [[Plasma (physics)|plasmas]] source), by focusing (pure electrostatic or with magnetic fields), or by the number of electrodes.