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

Magnus Danielson magnus at rubidium.dyndns.org
Sat Oct 1 09:22:45 UTC 2011

On 01/10/11 10:55, Attila Kinali wrote:
> On Tue, 27 Sep 2011 22:11:57 +0200
> Magnus Danielson<magnus at rubidium.dyndns.org>  wrote:
>> A hydrogen maser would be possible if you can tool such large
>> structures. The glaswork might be a challenge and also the magnet assembly.
> What is difficult about the magnet assembly?

You need to create a good gradient magnetic field to cause separation. 
This was in fact a problem which wasn't realized until Stern hooked up 
with Gernlach who had the magnets needed. Look up the Stern-Gernlach 
experiment as it is valid for all beams and the H-maser style of storage 
box masers.

If you want to avoid this you would have to use optical pumping. This is 
what the rubidium gas cell maser uses. Today you can use optical pumping 
using lasers which both require care in polarity issues (which the 
rubidium pumping doesn't need to bother with) as well as locking up on 
the frequency. See for instance the CSAC papers where this is done to 
cesium in a cesium gas cell assembly. It has also been done in the 
NIST-7 cesium beam.

>> A variant which might be of interest is ion traps. Should not need that
>> complex mechanics even if it has some challenges.
> Scratch that. Building traps requires highly controlled magnetic fields
> with precisly defined gradients, tunable lasers and stuff like that.
> Nothing you can get your hands on easily. And probably not something
> you can get working unless someone shows you how to do it.

In that case you run into the same problems again then.

>> Trying to approach any of these would require reading up on a large
>> number of articles and patents to kind of "learn" the field. In alla of
>> these, getting full performance would involved much effort.
> I wouldnt try to read patents. These are convoluted beasts, written by lawyers
> for lawyers. If you want to understand the technology, read the papers. Most
> of them are eithe freely available or for a small fee. If you have a good
> university nearby you can find them for sure in the physics library.

Having read some of the patents I know that they can be quite 
descriptive. There is a new tradition in patent-writing which you are 
refering to, but that is rare with older patents.


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