What is a Cesium Atomic Clock?
Since the 1950’s, NRC has used cesium atomic clocks, which are the world’s best timekeepers. They use the exquisite reproducibility of spinning atoms of the element cesium. Pure cesium is a beautiful silver-gold coloured metal that melts just above room temperature. It is uncommon only because it combines so easily with other common elements. Animated glass vial with 1g of liquid cesiumThe glass vial in this picture contains a gram of cesium: one year’s supply for a typical atomic clock, which does not recirculate the cesium atoms. A gram of cesium could be found in about a cubic foot of ordinary granite. Natural cesium is pure cesium-133 (55 protons and 78 neutrons in the nucleus, 55+78=133): it is non-radioactive.
