The combination of high vacuum and milliKelvin temperatures is far, far worse.
-John ================ > J. Forster wrote: >> >> If you try to cut corners with high vacuun technology, you will be >> disappointed. Even with all new parts and carefull assembly, you will >> almost certainly have to He Leak Detect the system to get it tight. I've >> done this stuff. It is doable but certainly not trivial. And you cannot >> be >> sloppy. >> > > > not trivial is an understatement.. > > High vacuum seems straightforward until you sweat blood on it. Oh. that > fingerprint that serves as a virtual leak for weeks. That Kapton tape > that trapped a few molecules of whatever under it and outgassed. > The gas diffusing out through the drilled bolt.. sure it's drilled, but > the conductance is so patheticaly low, you're literally waiting until > the gas molecules happen to randomly bounce their wey up the hole. > > > It is the most horribly frustrating experience you will have. Unless > you're running HUGE fast pumps.. then you just don't care.. Back when I > sweated this kind of thing, I would have killed for the size pumps we > run at JPL on the big vacuum chambers.. Outgas, what outgas, it just > gets pumped away... But when you're running a 2 or 3 inch diff or turbo > pump... > > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
