[time-nuts] Home built cesium clocks???
magnus at rubidium.dyndns.org
Sat Jun 28 11:14:28 EDT 2008
From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] Home built cesium clocks???
Date: Sun, 29 Jun 2008 01:52:36 +1200
Message-ID: <48664224.5070004 at xtra.co.nz>
> swingbyte wrote:
> > G'day fellow time-nuts.
> > I was just going through some old projects and found my old home-made
> > mass spectrometer. This was a project based on a design from either
> > Scientific American or The Amateur Scientist back in the '60s. I was
> > wondering if anyone here had heard of a similar project for a cesium
> > clock? Although my home built mass-spec wasn't in the same league as a
> > bought one, it did work and did get me a HD in physics! How hard is it
> > to make a cesium clock? Just thinking about it and wondering what is
> > actually inside the physics package.
> > Tim.
> Not a great deal:
> A Caesium oven
> A mechanical collimator for the Caesium beam
> A pair of state selection magnets
> A Caesium detector
> A pair of Microwave cavities
The microwave cavities should have a phase-stable distribution inbetween them
and also a stable physical distance.
Getter to capture stray atoms.
The physical package should be magnetically shielded.
Also, an ion pump.
A variation would optically pump the cesium beam rather than using the original
state selection magnets. I have not heard of any commercial cesiums using that
technique, it is only used in a few lab cesiums.
Masspectrometers seems to be the most popular detection method too, but
optical detection is again used in a few lab cesiums.
The physical package is along with the RF chain the most problematic parts.
The rest is no big magic, but needs to be done with care.
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