[time-nuts] Maser manual

Bruce Griffiths bruce.griffiths at xtra.co.nz
Wed Sep 1 20:45:41 UTC 2010

An early analysis of a fused silica loaded cavity by Sigma Tau:

Although the dielectric constant tempco and thermal expansion tempco of 
fused silica is low so is the dielectric constant so the reduction in 
cavity volume is relatively small.

The reduced Q of a dielectric loaded cavity may also be an issue in the 
absence of cryogenic cavity cooling.


Poul-Henning Kamp wrote:
> In message<4C7EB534.2040606 at xtra.co.nz>, Bruce Griffiths writes:
>> The tempco of the dielectric constant of sapphire is quite large so the
>> cavity resonance tempco is somewhat larger than that of an unloaded
>> copper or aluminium cavity.
> Yes, they write that cavity autotuning is a must.
> I still think that is a smaller problem than getting hold of and
> maching an unloaded cavity with the necessary shields.

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