RE: Cesium Clocks -Reply

["Charp, Paul" <pac4@ATSDTO1.EM.CDC.GOV>]

Paul is on the mark.  The Naval Observatory informaton regarding cesium 
clocks state that "A "cesium(-beam) atomic clock" (or "cesium-beam frequency 
standard") is a device that uses as a reference the exact frequency of the 
microwave spectral line emitted by atoms of the metallic element cesium, in 
particular its isotope of atomic weight 133 ("Cs-133"). The integral of 
frequency is time, so     this frequency, 9,192,631,770 hertz (Hz = 
cycles/second), provides the fundamental unit of time, which may thus be 
measured by cesium clocks"

For more information, check out http://tycho.usno.navy.mil/cesium.html
 ----------
From: radsafe
To: Multiple recipients of list
Subject: Cesium Clocks -Reply
Date: Tuesday, April 30, 1996 7:55AM

Steve:

Let me stick out my neck and hazard the guess that there is no such
thing as a cesium clock  using Cs-137.  There was a condemned man (I
wish I could remember his name) who, as he was about to be beheaded,
gave the headsman some money to make a clean job of it:  if I'm wrong,
make the correction relatively painless.

I believe the term cesium clock is used to describe a particular design of
atomic clock that utilizes the natural frequency of the cesium-133 (stable)
atom. In fact, I believe that the "atomic second" is defined as the time it
takes for the cesium electrons(?) to rotate 9,192 million times or some
such thing.

Best wishes

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov