Yup. If you do use oil, you need an LN2 trap. -John
=============== > Hi > > My guess is that you either need a cryo pump or ion pumps and a very good > seal. > > Bob > > > > On Sep 1, 2010, at 5:15 PM, Robert Darlington <[email protected]> > wrote: > >> You can pickup oil diffusion pumps pretty inexpensively. They're not >> quite >> ion pumps but they get you way down there and they're fast. With proper >> traps you don't really have to worry about coating your experimental >> physics >> package with oil. They're cheap to run and easy to maintain. Ion pumps >> are >> about as simple as things get and could probably be made very easily by >> some >> of us "vacuum-nuts" but I never had the need. Turbo pumps probably >> won't do >> the job and they're expensive and unforgiving. Not only did one of mine >> crash, it crashed when a sputtering gun melted through. 80,000 RPM >> spinning >> foil blades don't like hitting the gun cooling water very much! >> >> Good luck! >> >> -Bob >> >> On Wed, Sep 1, 2010 at 2:30 PM, Chris Howard <[email protected]> wrote: >> >>> >>> >>> Given the quality of vacuum the manual seems to imply, I'm guessing >>> this >>>> wont cut it. I'll bet that even low impurity Teflon has a long >>>> bakeout >>>> period. >>>> >>>> >>> Too bad they don't have some kind of "getter" to allow lower vacuum >>> specs. >>> I expect they thought of that. >>> >>> The thing does sound like a giant hydrogenated vacuum tube. >>> >>> >>> >>> _______________________________________________ >>> 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. >>> >> _______________________________________________ >> 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. >> > > _______________________________________________ > 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. > > _______________________________________________ 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.
