| 摘要 |
A novel technique for mounting a disc of lanthanum hexaboride electron emission material within a hot cathode assembly of an electron gun is described. The disc is partly received in a recess of a graphite mounting member and the combined disc and mounting member are pushed to the end of a 50/50 molybdenum rhenium tube which has a rolled over lip which engages the disc. Indentations are formed in the tube and these extend into the mounting member to secure the mounting member to the tube. All contacting surfaces between the disc and mounting member and between the disc and lip are previously coated with colloidal graphite to improve electrical and thermal conductivity. Prior to securing the disc and mounting member to the tube the tube is secured to an alumina support ring by cutting and forming retaining lips from the tube and by flaring an end of the tube. |
