Spectacular transport: Undulator moved to the electron storage ring BESSY II

A heavy-duty crane lifted the undulator from the testing hall onto a truck, which transported it to the truck sluice of the experimental hall. © HZB/S. Zerbe

Arrived in the experimental hall, the undulator was lifted into the storage ring with the overhead crane. © HZB/S. Zerbe

The last few meters the undulator was pushed on wheels through the narrow storage ring to its place of use. © HZB/J. Bahrdt

View of undulator CPMU17: The magnetic structures are hidden in a vacuum chamber. © HZB/J. Bahrdt

A worldwide unique undulator developed at Helmholtz-Zentrum Berlin (HZB) was installed in the storage ring BESSY II on September 20, 2018. It supplies the "Energy Materials In-Situ Lab EMIL" with the hard X-ray light from BESSY II. The transport of the six-ton device was spectacular: several cranes were used to transport the undulator just a few hundred meters from the production building to the storage ring.

Undulators are key components to operate electron storage rings. The electrons pass through complex magnetic structures and are forced into an undulating orbit. This generates synchrotron radiation of great brilliance. What is special about the new undulator is that the magnetic structures are located in a vacuum chamber and cooled with liquid nitrogen. This permits significantly stronger magnetic fields to be generated to deflect the electrons.

The CPMU17 undulator is a worldwide unique prototype developed entirely at HZB. The new improved design is quite different from existing cryogenic undulators. The planning, design and construction of the EMIL straight section, including the soft and the hard undulator and the machine optics adaption, took five years.

Material investigations in the wide energy range

The Max Planck Society (MPG) and the HZB jointly operate the „Energy Materials In-Situ Lab – EMIL“ at BESSY II. The new undulator CPMU17 supplies hard X-ray light for the CAT and PINK measuring stations of the MPG and for the SISSY-I & SISSY-II measuring stations of the HZB. A second undulator supplies the EMIL laboratory with soft X-ray light. This enables researchers to carry out material investigations in a very wide energy range (from 80 eV - 8 keV) and to flexibly adjust the energy of the photons for their experiments.

At the beginning of 2019, hard photons will be available for the first time for the commissioning of the monochromators. The researchers want to welcome the first “friendly users” at the EMIL beamlines at the end of 2019/beginning of 2020.