Hi A spherical set of cells is going to be a massive pain to fabricate. I believe you can hit < 5x10^-12 / sqrt(tau) with a fairly normal cell design and cavity design. There are some very basic issues with the photo detector’s S/N that also tip things towards a coaxial approach.
Bob > On Jan 10, 2017, at 10:43 PM, Bruce Griffiths <bruce.griffi...@xtra.co.nz> > wrote: > > A spherical cavity resonator with a spherical Rubidium cell configured as an > integrating sphere (to enhance the SNR of the optical absorption signal) is a > potential option. Its also possible to use the same cell to lock a 795 nm > laser to the desired wavelength. Fiber coupling the laser light could also be > useful.Note that with an integrating sphere (or any other random scattering > process eg scattering from colloidal particles undergoing Brownian motion) > laser polarisation isn't preserved which may be convenient.One potential > issue with an integrating sphere is the longevity of the diffusing coating > (typically Barium sulphate with an organic binder). Roughening (fine grind > followed by HF etch for stress relief) the outer surface of the cell is also > advisable to eliminate light pipe effects in the cell wall. > Bruce > > On Wednesday, 11 January 2017 3:54 PM, Bruce Griffiths > <bruce.griffi...@xtra.co.nz> wrote: > > > A goal with ADEV ~ 1E-13/Tau (for Tau <1000sec) may be feasible as its > already been done as part of a PhD thesis.Using as large a cavity as possible > is probably useful so that a large cell can be employed.What resonant mode is > desirable in the cavity?Do we need to avoid field reversal as in the hydrogen > maser? > Bruce > > On Wednesday, 11 January 2017 3:43 PM, Bob Camp <kb...@n1k.org> wrote: > > _______________________________________________ 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.
