Hi, On 2019-11-09 01:07, Poul-Henning Kamp wrote: > -------- > In message <[email protected]>, [email protected] writes: > >> Just wonder if some 5065A can get so impressive that they don't just >> make a modern large/cool cell classic Rubidium with modern electronics >> technology! Certainly would be cheaper and more long lived also. > But isn't that essentially what they have done ? Yes. > > The Rb-lamp-filter thing has been beaten to death. Its not like > people have not researched it in the last 50 years, but nobody > anywhere have found a way to get rid of the Rb/glass absorption > related aging or the pressure-sensitivity for that matter, so 5065 > performance pretty much is the best you can ever hope for there > as long as your customers are terrestial.
The wall shift, the buffer gas shift, the resonator shift and how these relate to environmentals in addition to the lamp intensity shift. All well researched. Rubidium as such is not a bad species to measure, on the contrary, we learned that it excels over cesium in laser cooled state, as the cross-section is smaller. > > Given that these two cold-Rb devices are 1st generation of their > kind and given how little time they have had to collect data on > them yet, both with respect to performance but also day-to-day > gremlin-wrangling, I wouldnt be at all surprised if the next > two generations of that concept delivers almost two orders of > magnitude improved performance. Long-term measurements is being done at NIST and OP/SYRTE, none being known to be extremely wreckless in this regard, to say the least. This is well understood techniques now, so that it matures into commercial products is not strange. It's worth noting that optically probed cesium also exists from Oscilloquartz, altering the beam standard techniques. Common to all three clocks is the fact that they use semiconductor lasers to pump and interact with the element, and therein lays also the challenge of having such laser-systems operating long-term. This is for sure the way forward, and these are just the for-runners of the continiously operating optical clocks that may one day become commercial products. So, while hydrogen masers may work and large cell rubidiums can be cleaned up, eventually we come to the point where these new techniques will take over for many good reasons. Maybe one day we will have time-nuts with cold rubidium clocks and maybe even optical clocks. Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
