| 摘要 |
<p>PURPOSE:To prevent falling and to keep the surface of a bulk getter by fastly holding a bulk getter between walls of a groove formed on the periphery of a smaller annular part of each magnetic pole. CONSTITUTION:A groove 15 is formed on each smaller annular part of magnetic poles 4 and 5 facing a cathode. A linear bulk getter 16 made of titanium, zirconium or tantalum is fitted in each groove 15, then the walls 17 of the groove 15 are calked to fasten the bulk getter 16, thus safely securing the bulk getters 16 without being made dirty with a brazing material while maintaining efficient gas absorbing ability.</p> |
