LS2 Report: Getting ready for the future of physics in the East Area

Upgraded beam lines will support existing and new collaborations in an environmentally savvy manner in one of CERN’s oldest facilities.



Upgrades in the East Area are turning the facility into a state-of-the-art research centre (Image: CERN)

The East Area may have been inaugurated more than 50 years ago, yet it is still as modern as can be: just as it did in the 1960s, the smaller of CERN’s two main experimental facilities for fixed-target physics and test beams, now packed with cutting-edge equipment after a four-year-long makeover, embodies the future of physics in terms of research, technology and the field’s relationship with its environment.

Outer shell, floors, cooling systems, power converters and, of course, magnets – the renovation works left nothing untouched, save perhaps for the foundation slab. Works on the infrastructure, which greatly improve the facility’s energy credentials, have been completed and already give the East Hall a modern look and feel. The primary focus of the LS2 works, the maintenance and upgrading of the beam lines linking the Proton Synchrotron’s proton beams to the many experiments of the facility, is also nearing completion.

All of the 61 power converters, as well as almost all services – including cables, cooling and floors – stand ready to support the four beam lines whose magnets, a mixture of refurbished and brand-new dipoles and quadrupoles, are currently being installed. This painstaking task should be completed by April 2021, in time for the start of operation in the autumn. The new laminated yoke magnets will run cyclically only when the machine is operating, as opposed to the previous magnets, whose continuous energy consumption was a source of energy waste. Together with the new SIRIUS power converters, they will greatly contribute to reducing energy consumption in the facility.

Dipole magnets of the MCB type - these magnets are currently being installed on the beam lines. (Image: CERN)

The new beam lines will be game changers for research in the East Area, which focuses on irradiation of materials, test beams and atmospheric science. The experiments, namely IRRAD, CHARM and CLOUD, as well as users among the LHC experiments and others, will now make the most of the particle beams whose energy range has been broadened to span a region of 0.3 to 15 GeV/c. These performances perfectly complement the energy range available in the North Area, ranging from 15 to 400 GeV/c. In addition, the secondary beam lines (transferring beams of particles like muons or electrons) will, for the first time, be able to deliver pure beams of these secondary particles, for more accurate and qualitative data-taking. These improvements, coupled with better instrumentation relying on scintillating fibre technology, have already attracted a number of potential new users, including neutrino research collaborations, in line with the recommendations of the European Strategy on Particle Physics.

Sébastien Evrard, from the Engineering department, led the renovation project. He believes that the works in the East Hall mark the beginning of a new era in experimental areas at CERN: “These facilities are finishing their first life and must embark on their second one. In that regard, the East Area could serve as a model for future upgrades in places like the North Area. These big investments yield abundant results.” Sébastien’s colleague Johannes Bernhard (beam line physicist and leader of the Liaison to Experiments section in the BE-EA group) can look forward to reaping the fruits of these investments after the start of data collection by the constellation of experiments that have also been working hard to upgrade their equipment.

And beyond the collaborations, other prized guests eagerly await the East Hall 2.0, as Johannes points out: “The winners of the Beamlines for Schools competition for high-school students always conducted their experiment proposals on one of our beam lines before LS2. It’s always a pleasure to welcome them at CERN and we are all really looking forward to making it happen again soon!”