This discussion reminds me of a time long ago when I worked at a University. We had one rather obnoxious Grad Student, who, although brilliant, was a Royal PITA.
So, while constructing his vacuum system, and getting hassled by him, I located one of the Universities residents, a large water bug. Which I let loose in the vacuum plumbing. He was beside himself for about a week, wondering why he could not get pumped down to the level he expected. 73, Dick, W1KSZ -----Original Message----- >From: jimlux <[email protected]> >Sent: Sep 2, 2010 6:29 AM >To: Discussion of precise time and frequency measurement <[email protected]> >Subject: Re: [time-nuts] homebrew H maser > >Poul-Henning Kamp wrote: >> In message <[email protected]>, Bruce Griffiths writes: >> >>> Indicates that the operating pressure at the hydrogen dissociator is >>> likely to be a few Torr or so. >> >> The pressure is basically: "As low as possible" in order to minimize >> hydrogen collisions (other hydrogen, walls) as much as possible. >> > > >A few torr is actually not a particularly high vacuum (e.g. your run of >the mill neon sign is pumped down a lot lower before being filled to a >few torr). > >PHKs comment implies you're looking for mean free path somewhat greater >than physical dimensions... >That would imply pressures less than a micron (0.001 Torr).. MFP = >5E-3/P with P in Torr.. 1 micron pressure == 5cm MFP > >The other thing is when you're looking at MFP comparable to dimensions, >you're looking at molecular pumping in some form (no more pistons or >rotary vanes or ...) > >_______________________________________________ >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.
