ALPHA Cesium Fontain Atomic Clock

The new ALPHA Cesium Fountain Clock is a type of atomic clock currently used for the definition of the SI second (the International System of units). This device, built for ALPHA by the National Physical Laboratory in the UK, will be used as the frequency standard for ALPHA’s measurements of the spectrum of anti-hydrogen in the future. Precision comparisons of the structure of hydrogen and anti-hydrogen will require frequency metrology with a precision approaching 1 part in 10^15. This device is a necessary upgrade for us to make progress from our current level of precision of 1 in 10^12. The International System of Units, known by the international abbreviation SI in all languages is the modern form of the metric system and the world's most widely used system of measurement.