[time-nuts] Time Dilation tinkering

[jimlux]

On 3/22/17 4:28 AM, Bob Camp wrote:
> Hi
>
> In this case, the vacuum might work against you. You change the pressure outside
> the package and you get a flex. Flex translates to dimensional changes. That gives you
> a frequency shift. People make absolute pressure sensors this way :) Rb’s are by no
> means the only frequency standard impacted by this effect. Precision OCXO’s have the
> same issue.
>
> If you had enough room inside the package, you could do a “can in a can” sort of approach.
> The outer vacuum sealed can flexes. The inner vacuum sealed can does not see anything.
> You don’t eliminate the sensitivity this way, you do attenuate it quite a bit with each layer.
> The question then becomes - is is worth the increase in size? Since the pressure sensitivity
> is well below many other environmental factors …. probably not.
>

The CSAC is a can within a can (or more properly, the physics package is 
inside a sealed can) but I don't know if there's vacuum inside the can.