| 摘要 |
PURPOSE:To lower a temperature of a main body, and also reduce deflection, by joining an electron emitting member consisting of tantalum to the front a cathode main body consisting of tungsten, and emitting thermoelectrons from here, in an electron gun used as a heat source to vaporize metal in a vacuum by means of long size shape electron beams. CONSTITUTION:In a linear electron gun, a cathode 1 is positioned/arranged in the rear of an anode 7 and a grid 6, and both the ends are supported with a support mechanism 3. At this time, a main body 5 of the cathode 1 is constituted by combining a tungsten material and a tantalum material 4 to play a role of electron emission with each other, and the shape is formed in a long size shape. At this time, a recess part is bored in front of the main body 5, that is, in the central part of the electron emitting directional surface, and the tantalum material 4 is buried here, and electrons are emitted from here. By constituting in this way, even if the main body 5 and the tantalum material 4 are heated up to the same temperature, thermoelectrons are emitted mostly from the tantalum material 4 according to size of a work function, so that a temperature of the main body 5 can be lowered. |
