[time-nuts] You can build a fountain from the things you find at home...

[Bruce Griffiths]

Poul-Henning Kamp wrote:
> In message<CAF_SE-DK+1h1T2xks1u19Ty7nSmXrtQD+zV_2WbS0NJm1ey4cA at mail.gmail.com>
> , Robert Darlington writes:
>
>    
>> So I find that somewhat surprising (Aluminum as a material for UHV systems)
>> because they outgas water -for months.  Anodized aluminum is especially
>> bad!  Did they make any suggestions on cleaning the oxide off before pumping
>> down and baking?
>>      
> No mention was made thereof.
>
> With good getters I'm not sure the water would be a problem.
>
>    
UHV operation isnt required, even the PTB fountain only has a background 
pressure of 5E-7Pa.
http://www.congrex.nl/EFTF_Proceedings/Papers/Session_2_Cold_Atom_Clocks/02_02_Gerginov.pdf

operation with somewhat higher background pressures (with increased 
pressure shift uncertainty) should be possible.

Bruce.