Abstract:
[Object] In the control of electron beam focusing of a pierce-type electron gun, any influences from the space charge effect and space charge neutralizing action within the electron gun are eliminated to attain complete control of an electron beam.[Solving Means] Feedback control of the pressure within the electron gun is performed by directly measuring temperature at an internal of the pierce-type electron gun. It is desirable that locations where the direct measurement of the temperature at the internal of the electron gun is performed are an anode (39) and a flow register (43). Further, the direct measurement can be performed at any one of a ring, an aperture and an exhaust pipe provided at an outlet or an inlet of any one of a cathode chamber (31), an intermediate chamber, and a scanning chamber (33). Accordingly, all of stabilization of beam producing area (optimized design of electron gun itself), stabilization of beam transporting portion and stabilization of beam using portion have become appropriate.
Abstract:
An insulating diaphragm can be disposed on the saddle of getter flash turntable or other fixture used to support a cathode ray tube during frit knocking with a high voltage. The diaphragm protects the integrity of the cathode ray tube by preventing arcing of the high voltage through the neck of the cathode ray tube and into the supporting saddle.
Abstract:
A method and apparatus for preventing oscillations in high-current electron guns. Spurious oscillations frequently occur as a result of interaction of the electron stream with the fields of resonant modes of the gun structure. The resonant impedances of the modes are lowered by damping with lossy dielectric or resistive materials which are suited to the high temperature and vacuum environment of electron guns. The lossy materials are located in places shielded from high electric fields applied to the gun. Lossy dielectric materials which are D.C. insulators may be used as insulating supports for gun electrodes.
Abstract:
A gridded convergent flow electron gun employs a dimpled oxide coated thermionic cathode emitter facing a centrally apertured accelerating anode. A multiapertured control grid is interposed in the space between the dimpled oxide coated cathode and the anode for pulsing the electron beam. A multiapertured shadow grid is disposed overlaying the emitting surface of the cathode emitter with the apertures of the shadow grid being in alignment and in registration with the respective dimpled areas of the emitter and the corresponding apertures in the control grid for projecting a multiplicity of non-intercepting convergent flow beamlets through the individual holes in the control grid. The shadow grid is placed in nominal contact with the cathode emitter and is made of a material having essentially the same coefficient of thermal expansion as the cathode. In a preferred embodiment, the cathode includes a nickel base member and the shadow grid is made of nickel.