[time-nuts] vs Hg ion? Re: GPS clock stabilitiy, Rb vs Cs

Poul-Henning Kamp phk at phk.freebsd.dk
Sun May 5 14:29:53 EDT 2013

In message <51867DF4.4010006 at karlquist.com>, "Richard (Rick) Karlquist" writes:

>BTW, it is important to understand that
>the architecture is the key factor, not the flavor of atom.

Well, somewhat.

Some flavours of atoms don't work with some architectures, so for
most of the stuff in reach for us, the atoms do indeed equate an

The exception seems to be fountains, which can run on pretty much
any alkali atom you care to feed it, and some even able to use
both Rb og Cs (Built to nail the Rb frequency firmly down, as
I understand it).

However, there seems to be actual differences between the flavours
of atoms in fountains, and USNO have picked Rb over Cs because
they get better results that way.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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