May be of interest. https://youtu.be/2J9Y1-gxxhE [https://i.ytimg.com/vi/2J9Y1-gxxhE/maxresdefault.jpg]<https://youtu.be/2J9Y1-gxxhE> EEVblog #1040 - Caesium Beam Frequency Standards<https://youtu.be/2J9Y1-gxxhE> youtu.be A look at the Caesium beam time and frequency standards at the Keysight standards lab in Melbourne Australia, with Peter Daly. Forum: http://www.eevblog.com/... -=Bryan=-