Hi, Dana. > What does 'EFOS' mean? I hadn't heard the term before.
EFOS was a series of masers made by Oscilloquartz in Switzerland, there is a little information on my website www.efos3.com under «about». The manuals for those masers are also available, lots of good info for the interested: http://www.leapsecond.com/museum/efos/ > I do hear mixed reports about where the conversion to atomic H > occurs, and consider the jury to still be out on that question. Well, I think that jury is in.. :) plenty of information in old papers on that part. Ole > I had thought that the volume of the storage bulb was much > smaller in out maser, perhaps in the pint to quart range. For a > frequency of ~1420 MHz, I guess it would take a cavity that is > operating in a somewhat higher than fundamental mode if the > volume is in the gallon regime as you suggest. But with the > narrow gain profile width of this transition, I supposed there'd > be no risk of the thing running in the wrong mode. > > Dana > > > On Tue, Nov 21, 2017 at 8:14 AM, Ole Petter Ronningen <opronnin...@gmail.com >> wrote: > >>> On Tue, Nov 21, 2017 at 2:50 PM, Attila Kinali <att...@kinali.ch> wrote: >>> >>> [...] The advantage of the platinum valve >>> system is that it "generates" single atom Hydrogen, as required >>> by the maser. >> >> >> Picking nits here.. It was my understanding that the splitting of molecular >> hydrogen into atomic hydrogen happens using RF in the dissociator - not in >> the platinum leak valve. Is my understanding incorrect? >> >> >>> Within the cavity there is a small glass bulb that keeps the atoms >>> in the right position of the cavity field. >> >> >> 4.5 liters in EFOS type masers - so not *that* small. I believe other >> masers are the same order of magnitude. >> >> >>> Yes, IIRC normal numbers are several 10s to 100s of wall collisions >>> before the atom loses its state due to wall colisions and without >>> contributing to the signal. >>> >> >> Lifetime ~1 second I think >> >> >>>> I've long wondered what causes the slow frequency drift, typically >>> amounting >>>> to about 3E-14 over a time span of several months. >>> >>> Mostly changes in the wall coating leading to a different wall collision >>> shift and mechanical changes of the cavity dimension (think air pressure >>> and creep) leading to a different cavity pulling. To a lesser extend >>> it's the changes in the quality of the vacuum and number of Hydrogen >> atoms >>> in the cavity. >> >> >> Also aging of electronic components - coarse tuning of the cavity is done >> by temperature, and any drift if the temperature-sensor/amplifiers etc will >> result in drift. At least for EFOS type masers. >> >> Ole >> _______________________________________________ >> 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. _______________________________________________ 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.
