CERN's CLEAR facility (Image: CERN)
CERN's CLEAR facility investigates novel medical applications of electron beams and the resilience of electronics in space. A short walk away on the CERN site, MEDICIS is developing ways to produce a new generation of radioisotopes with potential applications in precision medicine and theragnostics. The five-year extensions to these unique and versatile platforms approved earlier this year by the CERN Council will enhance and expand the beneficial impact of CERN's accelerator technology on society.
CLEAR, which is centred around a 20-m-long linear electron accelerator originally designed to develop future particle colliders, serves a wide range of experimental users from around the world. Among CLEAR's most significant contributions are its studies of very high-energy electrons for deep-tissue cancer treatment - including pioneering studies on FLASH radiotherapy, an ultra-fast delivery method that greatly reduces damage to healthy tissue, in collaboration with Geneva University Hospital. Another prominent example is irradiation campaigns carried out in collaboration with the European Space Agency, which have provided vital data to ensure that satellites and astronomy missions can withstand the harsh conditions of space.
In operation since 2017, CLEAR is now confirmed to run until at least 2030. To accommodate the growing number of beam requests, a new beamline is being built featuring two additional test areas: one in vacuum and one in air. This expansion will both increase the variety of beam parameters CLEAR can provide to users and create more space for multiple experiments to be conducted simultaneously.
For the first two years of its extended five-year mandate, CLEAR will focus on its core strengths: deeper investigations of very high-energy electron beams for medical applications, further studies on the radiation hardness of electronics, accelerator R&D, and training - including hosting the winning teams from the 2026 CERN Beamline for Schools competition. The CLEAR facility thereafter has a broad range of possibilities, addressing research demand in medical, beam instrumentation, and dosimetry domains while serving as a testbed for tools and techniques to characterise beam properties in next-generation accelerator injectors.
"CLEAR is well positioned to remain a flexible, high-impact facility for beam-based R&D, not only advancing accelerator physics, but contributing meaningfully to applications in medicine and space," says Mike Lamont, CERN Director for Accelerators and Technology. "MEDICIS, meanwhile, is helping to address the global shortfall in medical isotopes through close collaboration with the biomedical community. Together, these platforms show how CERN's accelerator know-how can deliver tangible societal benefit."
Operating within CERN's ISOLDE Class A nuclear laboratory, MEDICIS uses proton beams from the Proton Synchrotron Booster and advanced mass-separation technologies to produce innovative medical radionuclides for biomedical research. MEDICIS is a collaborative project involving 19 partner institutions, including hospitals and laboratories across Europe and beyond, such as CHUV, Heidelberg University Hospital, KU Leuven and others.
Since it came online in 2018, MEDICIS has successfully produced Actinium-225 (pivotal for targeted alpha therapy), ultra-pure Samarium-153 (enabling more effective and cleaner cancer therapies), and Tm/Er-165 (for molecular imaging and therapy research), among other radionuclides. It also played a central role in launching the European Union medical radionuclide programme PRISMAP, and this year was granted approval by the CERN Council to supply mass-separated radionuclides for clinical trials in collaboration with Heidelberg University Hospital.
With its mandate extended until 2030, MEDICIS aims to scale clinical-grade radionuclide production to facilitate the transition from research to experimental clinical applications, starting with Sm-153. It will continue to develop the next-generation theranostic radionuclides Ac-225, Sm-153, Ra-224 and Er-165 while exploring novel radionuclides for more targeted and less damaging therapies, as well as reinforcing its leadership role in the European radioisotope landscape with the proposal of PRISMAPplus.
