Dynamic, yet inertial – and definitely futuristic

Researchers conduct experiments to demonstrate inertial motion in magnetic materials

In the journal Nature Physics (DOI: 10.1038/s41567-020-01040-y), an international team of scientists from Germany, Italy, Sweden, and France report on their experimental observation of an inertial effect of electron spins in magnetic materials, which had previously been predicted, but difficult to demonstrate. The results are the outcome of one of the first long-term projects at the high-power terahertz light source TELBE at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR).

Today, most of the world’s “memory” is stored on magnetic data carriers – hard disks – without which our digital lives would be unthinkable. In the magnetic material, it is the electron spins that do the actual job of storing the data. Imagine this spin as electrons rotating around their own axes, either to the left or right – representing the digital “zeros” and “ones”.

There is something special about this rotation, as Dr. Jan-Christoph Deinert from the HZDR Institute of Radiation Physics explains: “In the magnetic field, the electron behaves like a tumbling spinning top. The rotational axis of the electron changes its direction on a circular path. We call this process precession. When disturbed by an external force, the rotational axis should also make small oscillatory movements, called nutation, which overlap the precession. Like precession, it is a characteristic of many rotating objects, from children’s spinning tops to planets like Earth. Due to its much smaller scale, however, nutation is far more difficult to observe.”

Read more on the Helzholtz Zentrum Dresden Rossendorf website

Image: An international team of scientists has managed for the first time to observe the ‘nutation’ of spins in magnetic materials (the oscillations of their axis during precession). Foto: Dunia Maccagni

An innovative mirror unit for soft X-ray beamlines at MAX IV

A new five-axis parallel kinematic mirror unit has been developed for MAX IV soft X-ray beamlines. Its development and technical characteristics are now described in a peer-reviewed article.

A new five-axis parallel kinematic mirror unit has been developed for MAX IV soft X-ray beamlines. Its development and technical characteristics are now described in a peer-reviewed article.

In an article published in March 2020 in the Journal of Synchrotron Radiation, a team from Uppsala University, MAX IV Laboratory, FMB Feinwerk und Messtechnik GmbH, and University of Tartu presents a five-axis parallel kinematic mirror unit specially developed for MAX IV soft X-ray beamlines. This new mirror unit has been created to address the unique stability requirements of 4th-generation synchrotrons such as MAX IV.

MAX IV has pioneered the development of the 4th-generation synchrotrons thanks to the implementation of the multi-bend achromat technology, a system based on the use of several sequential bending magnets in place of a single large magnet. Thanks to the introduction of this technology, the emittance has decreased by one order of magnitude, resulting in increased brightness. The multi-bend achromat system has also brought new challenges for the construction of beamlines. Decreased emittance of the storage ring has allowed for a smaller beam size, which, in turn, means higher requirements for electron beam stability, as well as for mechanical stability of the beamline components.

>Read more on the MAX IV website

Image: Veritas is one of the beamlines at MAX IV used for testing the prototype of the new five-axis parallel kinematic mirror.