[time-nuts] The forbidden question

[jimlux]

On 6/7/19 3:32 PM, Michael Wouters wrote:
> As promised, here's one pertinent paper, about using cryogenic
> sapphire oscillators at mm-wavelengths ( 1 mm = 300 GHz ).
> https://arxiv.org/pdf/1106.0021.pdf
> It's not the one I was looking for but it's a useful entry point.
> One interesting number is that at one mm, the coherence time is
> limited to at most tens of seconds because of atmospheric turbulence.
> Table 3 is worth a look too.
> 
> Cheers
> Michael



"The temperature sensitivity limits the performance. For example if the 
ambient temperature changes by 1ͦC in 500 s, the temperature coefficient 
of 10 ps K-1 limits performance to about 2×10-14"

Ain't that the truth...


A nice paper describing a lot of the trials and tribulations of high 
performance oscillator measurement.