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How does a sputter ion pump use titanium to remove gases?
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vacuum technology
Diagram of a McLeod gauge.
A sputter ion pump removes gases from a vacuum system by utilizing the sputtering principle, where a cathode material—typically titanium—is vaporized through bombardment by high-velocity ions.1
The process functions through three primary mechanisms depending on the type of gas:
- Active gases: These are removed through chemical combination with the freshly sputtered titanium.1
- Inert gases: These are pumped by being ionized and subsequently buried within the cathode material.1
- Light gases: These are removed by diffusing into the cathode.1
In a typical configuration, the pump features two flat titanium cathodes and a stainless steel anode assembly, all surrounded by a permanent magnet. The anode operates at a high potential (approximately seven kilovolts), while the cathodes remain at ground potential, facilitating the ion bombardment necessary to sustain the sputtering process.1