LINAC4 takes a tour of Europe

Along the German Autobahnen, a truck carrying 20 tonnes of copper is on its way to Poland. The metal has already made a short tour of Europe, yet the drive across the high-speed highway is only the beginning of its transformation into CERN’s next linear accelerator, LINAC4.


Grzegorz Wrochna (left), director of the Andrzej Soltan Institute for Nuclear Studies (IPJ), and Rolf Heuer (right), CERN DG, sign the framework agreement between the two institutes.

By the summer of 2012, the PI-Mode Structures (PIMS) will be constructed and completely installed in the LINAC4 tunnel. The PIMS cavities are the final accelerating structures needed for LINAC4, and have been designed to accelerate protons from 100 to 160MeV. While the first cavity was built entirely at CERN, construction of the remaining cavities has become a larger, multi-national operation.

In a 1 million euro framework agreement signed on 11 February by the Director-General, the Andrzej Soltan Institute for Nuclear Studies in Swierk (Poland) was given the task of constructing the PIMS cavities. They will work in collaboration with the Forschungszentrum Jülich in Germany to complete the work within the next 18 months. “By spreading production across various institutes, we can share CERN technology with our partner laboratories while also reducing the overall costs and manpower,” says Frank Gerigk, the project engineer responsible for the Linac4 accelerating structures.

“PIMS cavities have previously only been used to accelerate electrons, so constructing 12 modules for low-energy proton acceleration is a venture that only cutting-edge research institutes could take,” says Tadeusz Kurtyka, from the Office of the Director for Accelerators and Technology. “After they’ve finished construction, the Soltan Institute will be able to use the CERN technology developed for the cavities in their future accelerator projects, developing industrial and medical electron accelerators.”

The PIMS prototype designed and built at CERN.

Monitoring the construction of the 12 PIMS cavities will require a degree in geography as well as engineering! It took over 18 months for CERN to amass the 40 tonnes of difficult-to-produce, 3D forged copper from a French supplier required for the cavities. First used to construct the original PIMS module at CERN, the copper now makes its way to the Soltan Institute in Poland. From there, it will visit the Jülich centre for a sample of their prestigious welding techniques. Finally, the finished cavities will make their way back to CERN, two at a time, for assembly and final tuning.

This summer, the first PIMS cavity will complete its journey at CERN, where it will immediately be tested and prepared for installation. When the final cavity arrives in July 2012, after assembly and tuning, installation will immediately begin inside the LINAC4 tunnel.

by Katarina Anthony