Hi The exact "fill" in the lamp is one of those things the Efratom does not like to talk about. Best guess is that there is more than just Rb in there.
Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Neville Michie Sent: Tuesday, September 29, 2009 12:19 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Can anyone spare an LPRO lamp? The lamp in the LPRO may have a significant difference from the other lamps. The pictures of lamps on Tom's ? page show that each of them has a side arm which is most helpful for filling. The side arm is left out in the cold so any excess rubidium condenses there as a reserve supply. The vapour (vapor) pressure of rubidium is then determined by the temperature of the side arm. The LPRO does not seem to have a side arm, at least I did not see one when I looked at mine, and if it has it does not seem to protrude out of the oven. I can not guess how they filled it. Remember it is mainly empty, I think, although it may have an inert gas in it besides the rubidium vapour. With the right amount of rubidium in the tube the pressure will always be right, the only problem is that alkali vapours are infamous for diffusing into warm glass, and with no backup supply of rubidium the vapour pressure will drop and the fire will go out. Can anyone tell me what the lamp looks like? Mine seems to be a simple glass sphere. cheers, Neville Michie _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.