There's been a fair number of papers from Hahvahd about bulb coating for masers. Interestingly enough, here's a patent:
http://www.google.com/patents/US3859119 from 1972. I had to figure this out, but Yuri is referring to flourophosgene a.k.a. carbonyl flouride. If you'd like to read a really nice detailed paper on bulb coating for Rb cells, try this one out: http://walsworth.physics.harvard.edu/publications/1999_Phillips_otherdoc.pdf On Mon, Nov 3, 2014 at 3:46 PM, Chuck Harris <[email protected]> wrote: > Hi Yuri, > > It would be a very good idea to keep the temperature of > the nichrome wire low, and that might be the biggest problem > with the vacuum deposition technique... the wire could get > too hot in some places, and stay too cool in others. > > A really uncontrolled experiment, aka: a thermal wire stripper, > gets covered with white snow from the teflon vapor released > while stripping teflon wire. > > -Chuck Harris > > Yuri Ostry wrote: > >> Hello, >> >> Monday, November 3, 2014, 5:40:30, Chuck Harris wrote: >> >> C> I would think that making the teflon coating would be pretty easy. >> >> C> What I would try is to put a nichrome boat, and some teflon into the >> C> vessel, and pull it down to a good vacuum. Then heat up the boat, >> C> and the teflon should sublime, and condense on the walls of the >> C> vessel. >> >> C> The nichrome boat could be something as simple as wrapping the nichrome >> C> into a solenoid form around some teflon rod. >> >> C> -Chuck Harris >> >> Teflon decomposes at high temperatures, releasing some sublimate and a >> lot of really nasty chemicals, like fluorfosgen. There is a chance >> that really thin even coating can be produced this way, but a lot of >> experimentation would be needed. >> >> I would try to take samples of PTFE-insulated hookup wire (from different >> manufacturers, say white Alfa or Belden wire and russian MGTF wire that >> use >> slightly different PTFE formula) and try to make coating inside glass >> tube samples, using copper wire as heater by itself. >> >> I doubt that there will be good results, though. "Classic" way with >> thin slurry application and heating to teflon melt point to make solid >> film may be more "realistic". >> > _______________________________________________ > 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.
