Conditioning & Bakeout

Bakeout and plasma conditioning drive residual gas from interior surfaces to reach and hold the vacuum quality the plasma needs.

Fresh or freshly opened vacuum surfaces hold adsorbed water and gas that would spoil plasma performance. Bakeout heats the vessel to drive off this load, and plasma conditioning further cleans plasma-facing surfaces. Together they bring the machine to the vacuum quality steady operation requires.

Bakeout

The vessel and internals are heated for an extended period while pumping continuously. Elevated temperature accelerates desorption of water and gas so the pumps can remove them. Bakeout is planned into installation and into any maintenance that breaks vacuum, because it sets how quickly the machine returns to service.

Plasma conditioning

• Low-power plasma discharges scrub plasma-facing surfaces
• Impurity and gas levels are tracked as conditioning proceeds
• The process continues until vacuum quality meets specification

Return to service

Conditioning time is a real contributor to how long a vacuum-breaking maintenance activity keeps the machine down, so procedures aim to minimize exposure and streamline the return. Conditioning and bakeout are specified at design stage against the frozen machine's operating pressure requirements.