[time-nuts] Cs beam cavity: why is it U shaped?

[Tom Van Baak]

The U shape is called the Ramsey Cavity:

<http://www.nobelprize.org/nobel_prizes/physics/laureates/1989/ramsey-lecture.pdf>

/tvb

----- Original Message ----- 
From: "Attila Kinali" <attila at kinali.ch>
To: <time-nuts at febo.com>
Sent: Tuesday, May 01, 2012 9:47 AM
Subject: [time-nuts] Cs beam cavity: why is it U shaped?


> Moin,
> 
> For some time now, i'm wondering why the microwave cavity of Cs
> beam standards is U shaped. Ie why does the Cs beam fly first
> trough the first "sub"cavity, leaves it, flies a substantial
> length trough free space, passes the second "sub"cavity and
> then goes to the detector.
> 
> If the interaction time with the microwave field would be an
> issue, i would expect the beam to pass trough a longer stretch
> of the cavity, and not two time trough a short stretch that
> are widely spaced.
> 
> Unfortunately, none of the papers i've read has shed any light
> on this, and google isn't helpfull either.
> 
> Could anyone here enlighten me?
> 
> Attila Kinali
> 
> -- 
> Why does it take years to find the answers to
> the questions one should have asked long ago?