Hi
> On Mar 25, 2018, at 9:18 AM, Attila Kinali <att...@kinali.ch> wrote: > > Moikka moi, > > In the past, it has been again and again claimed that the HP 5065 has > such an outstanding short term stability because of its large vapor cell. > But the more I read, the less I believe this. E.g. if you look at the > papers by the group around Gaetano Mileti and Christoph Affolderbach > from University of Neuchatel, you'll see that they get an ADEV well > below 1e-12 with a vapor cell that is just 3x3cm (actually smaller > than that... but details). Yes, they use a laser instead of an Rb lamp, > which increases SNR. But that would mean it's not the cell size per se > that limits the short term stability, but the pumping of the atoms > and the light noise on the photo cell. Hence it should be, theoretically > at least, be possible, to take one of the telecom Rubidium standards, > replace the lamp with something better, and come close to the performance > of an 5065.... So, what part of this is wrong and what am I missing? Well, magnetic shielding, temperature coupling between cells, photo detector noise floor, phase noise of the various signals, basic stability of the “ocxo” and I’m sure a few other issues as well…… Bob > > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > _______________________________________________ > 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.