Recipient (vacuum technology)

Example for recipient : An ultra-high vacuum chamber (pressure <0.5 · 10 ⁻¹⁰  hPa) for photoelectron spectroscopy with a hemisphere analyzer, X-ray tubes and various preparation methods from Omicron

In vacuum technology , a vessel is referred to as a recipient : the vacuum is created in it by sucking off the contained gases with the help of suitable vacuum pumps . The recipient is usually made of stainless steel, in earlier times glass was also common.

So that the vacuum remains stable, a recipient is sealed so that no liquid or gas exchange with the environment can take place.

Detachable connections on the recipient (flanges) are sealed with elastomer or metal seals. A sealing material that is often used is Viton ; in systems for ultra-high vacuum, copper seals are also used, previously also seals made of gold wire. Teflon is used as a sealing material, especially for mechanical feedthroughs and valves . In the low-temperature physics come Indiumdichtungen used.

For fast reaching the ultra high vacuum to 200 ° C, with high demands on the vacuum even up to 400 ° C has the recipient to be heated to be. For this purpose, built-in heating conductors are used in the recipient, where this is not possible, can be baked out by means of electrically heated heating jackets wound around the system. Some UHV systems are operated at lower temperatures (e.g. 0 ° C) (advantages: lower vapor pressures, no icing, effective pumping, low diffusion). To do this, the recipient must be thermally isolated from the environment, e.g. B. by means of a pre-vacuum, which also reduces the leakage rates and enables more targeted leak detection using helium. Baking out can be supported by glow discharge or UV lighting.