The so called UHV, is a kind of vacuum characterized by pressures lower than approximately 10−7 pascal or 100 nanopascals (10−9 mbar, ~10−9 torr). UHV needs to be constructed with uncommon materials, and the entire system require to be baked to eliminate water and some other trace gases that adsorb on the chamber’s surfaces.
Achieve an Ultra High Vacuum is not something real easy, you would seriously consider to talk to a specialist in this field, they are a perfect solution for X-ray photoelectron spectroscopy, Gravitational wave detectors, Thermal desorption spectroscopy, Particle accelerators, Scanning tunneling microscopy, etc…
Of course in a ultra high vacuum you can’t use only one pump, but you will need a series of various vacuum pumps.
The vacuum pumps most used to reach UHV include the Cryopumps, the Ion pumps, the Turbomolecular pumps, the NEG pumps and the Titanium sublimation pumps.
Most of the time, when you search a UVC with the characteristic that you need, you won’t find it! I know it can sound crazy but everyone have its own needing and of course the manufacturers can’t build thousands of different vacuum chambers and ultra high vacuum without being sure they gonna sell them, so they just build vacuum with standard measures (and when I say vacuum I mean also thermal vacuum, vacuum pumps, etc..).
However a solution to this problem is available just right here: Custom Chambers!
Nowadays infact is possible to order a UHV that suit us best with the characteristic we want and we need. Of course I recommend you to always look around first, expecially online, because a custom chambers is yes a good idea but sometimes it can reveal expensive; thank God there are the “Free Quote” modules in almost every manufacturers website (and in this case I suggest you to ask a free quote to at least 4-5 different manufacturers).
As far as I know, some of the best UHV are produced by Huntington Mechanical Laboratories, an American based company.