18 April 2026

Photo: AG Garutti

MADMAX team proudly presents a cooling cryo in Hamburg.

Photo: AG Garutti

MADMAX cro starts his work to cool down in April 2026 in Hamburg.

Photo: AG Garutti

All set up for the MADMAX cryo and his work in cooling down.

This Wednesday, after a bit more than two weeks of pre-cooling, we managed to fill the MADMAX Cryostat with liquid helium and to activate the closed-loop mode of the system. This milestone marks the start of the Site Acceptance Test (SAT) for this unique piece of equipment which was designed, build and delivered to us by Bilfinger Nuclear & Energy Transition. Once filled with liquid helium from a dewar, the system operates in a closed cycle using five pulsetube cryocoolers from Sumitomo (SHI) Cryogenics of Europe GmbH to keep a large inner volume at about 4 K. The cryostat is now operating in a steady state with heaters simulating the heat loads of the equipment and components to be later installed for the MAgnetized Disc and Mirror Axion eXperiment MADMAX.

Once the SAT has finished, the installation of these equipment and components will start, turning the MADMAX cryostat into a full dielectric axion haloscope. After commissioning in the shielded lab SHELL (an infrastructure of the Cluster of Excellence Quantum Universe), the whole experiment will travel to CERN in 2027 to perform an axion physics run inside the magnetic field of the MORPURGO magnet.

A big "Thank You!" to all people involved in this challenging project! Especially, to Eugen Shabagin from Bilfinger Nuclear for the very fruitful collaboration on this project and the help and support in trouble-shooting during commissioning of the MADMAX Cryostat.

Please find more information:
Group Garutti https://www.physik.uni-hamburg.de/iexp/gruppe-garutti.html
MADMAX Collaboration https://www.mpp.mpg.de/en/research/astroparticle-physics-and-cosmology/madmax-searching-for-axion-dark-matter/
Excellence Cluster Quantum Universe https://www.qu.uni-hamburg.de/