Hi OK, it works better if it bounces off the wall. The line width is narrower. Does it work at all (is there a line you can find) without the coating?
Yes you would need to find a paper from the 1960’s to find anybody trying to run one that way. Bob > On Nov 2, 2014, at 5:04 PM, Magnus Danielson <[email protected]> > wrote: > > Hi Attila, > > On 11/02/2014 10:43 PM, Attila Kinali wrote: >> On Sun, 2 Nov 2014 16:28:47 -0500 >> Bob Camp <[email protected]> wrote: >> >>> It’s been way too many years since my last Maser play session … >>> >>> Will it fire up *without* the Teflon coating on the bulb? Yes it works >>> *better* with the Teflon (less wall interaction). Getting the bulb >>> re-coated might be a major pain. >> >> According to some of the papers i've read, parafin might be an alternative >> to Teflon. The interaction of Hydrogen with Teflon is lower than with >> Parafin, but it might be acceptable (Curiously, if it were a Rb maser, >> you'd use a parafin coating instead of a Teflon coating). > > Parafin was used early, but in the strive to even further increase the > interaction time with the hydrogen in the "bouncing box", telfon was > preferred. > > In the early days they experimented with different coatings. The goal was to > increase the time (and thus narrowing the bandwidth) of interaction before > the hydrogen atoms loose state and cause a frequency shift. Rubidium gas > cells have similar wall-shift, but advancements have stabilized the > wall-shift by buffer-gas selection. > > A way to estimate the wall-shift is to run different sizes of glas-bulbs, and > notice the maser frequency shift. > > The old hydrogen masers where really experimental platsforms to a much higher > degree, but that also meant that validation was done. > > Then again the cavity shift is there, something that can be measured and > compensated as a separate control loop, which has contributed to increase the > stability and thus performance. Some hydrogen masers have proven themselves > to be much more pressure sensitive than others. > > Finding the lack of hydrogen masers in my lab disturbing. > > Cheers, > Magnus > _______________________________________________ > 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.
