| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an electron gun in which a pin and a cathode support ring are not fused even if the cathode is heated to high temperatures. <P>SOLUTION: The electron gun 10 has a case 11. A cathode member 31, a heating device 32, and an anode electrode 3 are arranged in the case 11. The cathode member 31 has a cathode electrode 1, three pieces or more (here, four pieces) of pins 15, and a support member 5. The cathode electrode 1 is made of tungsten, and the inner circumferential face of the supporting side hole 70 of the support member 5 has carbon, graphite or tantalum carbide with a higher melting point than tungsten exposed, thereby, when the cathode electrode 1 is heated by the heating device 32, the inner circumferential face of the hole does not melt by radiation or heat conduction and the pins 15 arranged inside the hole are not firmly fixed. Furthermore, when the pins 15 and the support member 5 are thermally expanded, there occurs less phenomenon that the pins cannot be pulled out due to friction, and position shift of the cathode electrode 1 is not caused. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
