At the beginning of November, a caesium fountain was launched at the Poznan Supercomputing and Networking Center. The device was built in the National Physical Laboratory (NPL) in Teddington near London, under the direction of an outstanding specialist in the field of atomic frequency standards, Dr Krzysztof Szymaniec. The caesium fountain will join the ranks of several most accurate atomic clocks in the world and is the second such clock in Poland.

The Fountain is owned by the Space Research Centre of the Polish Academy of Sciences, and its launch in PSNC is an effect of cooperation between the mentioned institutions. The first Polish fountain has been working since 2016 at the Astrogeodynamical Observatory in Borowiec in the Laboratory of Time and Frequency (AOS) under the direction of Dr Jerzy Nawrocki.

In a device such as the caesium fountain, a cloud of caesium atoms is cooled down and thrown with laser light in the vacuum chamber, resembling a jet of water in the fountain. The cloud of atoms during the flight upwards and during gravitational falling is illuminated by microwave radiation. If it has a suitable frequency, the atoms are stimulated to vibrate. If the microwaves are tuned to the resonant frequency, which excites the most caesium atoms, we obtain the standard realization of a second (from 1967 the second is defined as the time equal to 9 192 631 770 radiation periods of the caesium-133 atom).

We invite you to watch the photoreport from the fountain installation.

Agnieszka Wylegała