[time-nuts] time-nuts Digest, Pressure senitivity of Rb vapor cell

[Andre]

Incidentally that might be a good experiment. Put a Rb module in a temperature compensated 
variable pressure chamber with a sensitive (eg BMP350) chip and see what changes.
The better units may have this integrated but I doubt it.

>From memory this became redundant on the newer generation clocks when the whole assembly
was sealed with (IIRC) pure argon at intermediate pressure to reduce corrosion over time.
Could this be one reason why the modules on Galileo broke? Would make sense.


Subject: Re: [time-nuts] Pressure sensitivity of Rb vapor cell
        standards
Message-ID: <20200219181647.491f48c3d4849acde93a7673 at kinali.ch>
Content-Type: text/plain; charset=US-ASCII

On Wed, 19 Feb 2020 01:40:56 +0100
Magnus Danielson <magnus at rubidium.se> wrote:

> The one thing that one now suffers is that the intensity changes as the
> servo pulls it around, I've not seen an explanation of how that is
> handled for CW operation. For side-band operation one can use the
> AC-modulation amplitude, as one disperse energy from the central carrier.

In those systems where they care about this, they use an additional
loop, outside of the laser head itself, that uses an acusto-optic modulator
to control the intensity. The second paper that I cited in the original
mail mentions that as well.


                                Attila Kinali



Attila,

I believe your original question was how to compensate for atmospheric
pressure changes on the cell.

It is the cell that is affected by pressure NOT the lamp!

This post gives some info.

https://www.febo.com/pipermail/time-nuts/2016-May/097829.html

Cheers,

Corby