| 摘要 |
<p>PURPOSE:To make an electron gun of a long life with a large amount of current by using a single crystal of LaB6 of a stepped cylindrical shape for a cathode of the electron gun. CONSTITUTION:A single crystal of LaB6 which is easy to process is used as a material for the cathode. The single crystal is provided with a step which is utilized to support the single crystal. As the material for the support member, any material is selected which is conductive, having a melting point higher than the operating temperature of about 1700 deg.C or lower of the LaB6 cathode, and reacts less with boron, such as tantalum, molybdenum, rhenium, carbon, etc.</p> |
