[time-nuts] Re: hydrogen rich environment and oscillators

[Lux, Jim]

On 12/13/22 1:24 PM, Poul-Henning Kamp wrote:
> --------
> Lux, Jim via time-nuts writes:
>
>> Is there a cheap connector/feedthrough that can take 100 psi or so to be
>> able to make measurements "in-situ"?
> Use a window and optical transmission ?
>
It's hard to get power in with optical transmission.

Say you have your favorite 10811 based GPSDO and you want to see how 
it's going to work in your diving bell loaded with heliox (with a coax 
cable to a floating buoy with the GNSS choke ring antenna) - but not 
really...

This is sort of different from the whole He, H2 question - but it raised 
the interesting question of operating devices at pressures other than 
room temp.  We've talked a lot on the list about schemes of varying 
complexity to thermally isolate an oscillator - well, putting it in even 
a partial vacuum might  be effective, one really wants to get the MFP to 
"bigger" than the gap between device and wall, so convection stops being 
an issue: then it's just radiation, but even if you pump down to, say, 
1/100th bar, the bulk thermal conductivity will be (I think) 1/100th of 
what it is in "room air".