Unfortunately, I'm 2000+ miles East of there.
When I told him about the 5334A purchase, he replied “Oh yeah, I was the project lead for that one.”
You can see the loot here: https://tomverbeure.github.io/2023/06/16/Frequency-Counting-.... I bought another HP counter today in Monterey… It’s like bicycles: the perfect amount to own is +1.
I think that makes me a qualified Quantum Mechanic. ;-)
The Cesium beam clock actually has a stream of atoms flowing through it, which is finite, leading to tube lifetimes of a decade or less.
The rubidium clock has a number of cells of rubidium gas, one of which is a light source, the other of which gets hit with RF, and if the frequency is just right, it absorbes about 1% of the light before it hits the detector.
A much smaller physics package, to be sure. They do drift, though, a tiny bit.
It’s also a great way to reunite with coworkers from times past, although I have really a bad memory for faces.