After many modifications, we have finally installed the latest version of our Zeeman Slower with permanent magnet. It is designed to cool atoms from 400 m/s to 15 m/s in 30 cm. This length is due to the fact that ytterbium is a heavy atom and needs more space and laser power to be cooled to 4-5 Kelvin.

Our Zeeman Slower consists of 26 permanent magnets arranged in the transverse-vertical plane of the atomic beam, which we use to generate a customised magnetic field to compensate for the Doppler effect caused by the initial velocity of the atoms.

The structure is made from a non-magnetic polymer material using a 3D printer. The arrows indicate the magnetic moment of each magnet for illustrative purposes.

The most curious thing about this design is the arrangement of two 8 screws in the last two magnets (2 screws per magnet), with which we can modify the radial distance of the magnets and control the speed of the atoms at the exit of the Zeeman Slower.

In the following figure, we see two different graphs showing the simulation of the Zeeman Slower presented and installed in the Yb optical clock.
At the top, each line represents an atom with a certain speed at the furnace exit (vertical axis). As it passes through the Zeeman Slower, its speed is reduced to a few metres per second.
At the bottom, you can see the shape of the magnetic field created by the magnets (in green), to which the atoms are subjected once they are inside the Zeeman Slower.