[time-nuts] Used Hydrogen Maser

[jimlux]

On 7/10/19 6:10 AM, Azelio Boriani wrote:
> Tom Van Baak said on Aug 29, 2013:
> 
>> The pursuit of precision tends to be exponential rather than linear.
> ...
>> As a rough example in the ADEV world:
>> - for 1e-11, you can buy almost any XO, TCXO, or risky OCXO for $10.
>> - for 1e-12, you can find a reputable OCXO on eBay for under $100.
>> - for 1e-13, you can find an old but maybe working cesium clock for 1 k$.
>> - for 1e-14, spend 10 k$ and get a certified working hp 5071A.
>> - for 1e-15, spend 100 k$ and find a used active H-maser.
>> - for 1e-16, spend 1 M$ to hire physicists and build a Cs fountain.
>> - for 1e-17, spend 10 M$ to fund a national research institute to build ion or
>> optical clocks.
> 
> 
> Add the 1k USD running cost per year just to keep the active maser running.
> I think that chances of finding an active H-maser used are near 0.
> Better to stick with GPSDOs: they bring into your home the stability
> and accuracy of the USNO UTC (well, close to...).
> 


I wonder what it would cost to build a trapped Hg ion clock - I don't 
think it's $10M, but it might be in the range of $500k-1M if you pay 
people to do the work.  Things like the quadrupole trap and ion sources 
are catalog items.  The whole vacuum system, including a turbo pump, is 
probably in the $10k range (looking at the Cole Parmer catalog, first 
hit on google), maybe another $5k in various vacuum plumbing bits and 
pieces.

back in 2005-2006 (published in 2007), Prestage et al had a lab version
https://ieeexplore.ieee.org/document/4319251

pumped, backfilled with Ne, then sealed