| 摘要 |
PURPOSE:To form a long-life stable ion source, by coating a tungsten filament with titanium first, then further with TiC. CONSTITUTION:A filament 4 is formed by coating an approximately 2phi diameter tungsten wire 5 with about 1,000Angstrom thick Ti 6 using a preferable coating technology, further with about 10mum thick TiC 7 similarly. Thus constituted filament 4 with a strong surface layer of TiC 7 against spatter has equivalent emission efficiency at a lower temperature to that of a tungsten filament (tungsten: 2,700 deg.K, Ti: 2,000 deg.K), and has long-run stability.
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