[time-nuts] More HP5065 experiments

[Attila Kinali]

On Sun, 27 Sep 2015 07:46:26 +0000
Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:

> Discovery of the day:  The voltage supplied to the Rb87 lamp changes
> the frequency on the order of 1.5e-11 per volt.
> 
> I have no idea why...
> 
>     http://phk.freebsd.dk/hacks/HP5065A/index.html

My first guess would be "light shift" (aka "AC Stark effect").
Does the intensity of the lamp change as well?

Also, it could be that the other spectral components of the lamp
(due to Xe/Ne gas filling) get stronger modulation than the Rb D1 line.

The only paper I know about that deals with the spectral modes of the
Rb lamp is [1], but as it is quite current, it does not deal with much
of the basics, but it might provide you with some references.

There should be somewhere a mention how much the frequency shift
of an Rb vapor cell due to light intensity change is, but i couldn't
find a good number in a couple of minutes. If you need one, please let
me know and I look a bit more carefull.

			Attila Kinali

[1] "rf-power and the ring-mode to red-mode transition in an inductively
coupled plasma", by Coffer and Camparo, 2012
http://dx.doi.org/10.1063/1.4705469

-- 
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