STFC Daresbury laboratory accelerator reaches 250 million electron volts milestone

Breakthrough at Daresbury Laboratory positions CLARA as a leading hub for accelerator innovation in Europe.

The Science and Technology Facilities Council’s (STFC) Daresbury Laboratory has achieved a major scientific milestone with their Compact Linear Accelerator for Research and Applications (CLARA) successfully accelerating electrons to an energy of 250 Million electron Volts (MeV).

This breakthrough marks a significant moment in the development of one of the world’s brightest medium-energy electron beams, opening the door to a new generation of experiments previously unattainable in the UK.

CLARA has been designed to develop and test next-generation accelerator technologies and is planning to welcome users in 2026. This will allow researchers to explore innovations that will shape the future of medicine, high energy physics, material science and beyond.

Accelerating Innovation: Building Tomorrow’s Technologies

By accelerating electrons to near the speed of light, CLARA will support research into smaller, more efficient particle accelerators with real world applications, including new modalities of radiotherapy.

Having reached the 250 MeV milestone, CLARA can now support more ambitious research programmes and prototype technologies that were previously out of reach in the UK.

A technical triumph

To reach this energy level, electrons were generated in a radiofrequency (RF) gun and accelerated using three 4 meter long, 3 GHz (gigahertz) RF accelerating cavities. A network of 77 electromagnets and 65 diagnostic devices were used to focus and steer the beam through the 60-metre-long facility.

This is the highest energy achieved in an accelerator at Daresbury Laboratory since closure of the Synchrotron Radiation Source (SRS) in 2008. Achieving full energy has increased the beam brightness by a factor of 100 and repetition rate by a factor of ten, transforming CLARA’s capabilities.

From Pioneering Research to Real-World Impact

Located at Sci-Tech Daresbury, in the Liverpool City Region, first phase of CLARA has already supported two successful user programs, resulting in numerous peer-reviewed publications. These include a UK-first study into novel radiotherapy technique aimed at delivering more targeted cancer treatments with fewer side effects.

With the 250 MeV upgrade, CLARA is now entering a new phase of advanced experimentation. A key part of this is the commissioning of FEBE (Full Energy Beam Exploitation), a shielded experimental area that allows researchers to conduct experiments without interrupting accelerator operations. This ensures faster setup times, stable beam delivery, and greater flexibility for complex research.

CLARA will also feature a new 120 Terawatt ultra-short-pulse laser, enabling unique experiments that combine high-powered lasers with bright electron beams. A capability unmatched anywhere else in Europe.

Looking ahead: Opening to users in 2026

CLARA is set to welcome users to this leading facility in 2026, offering UK and international researchers access to fully characterized electron beams tailored to their scientific needs It will support developing the accelerators of the future to be more affordable, more compact and more sustainable.

This transition firmly establishes CLARA as Europe’s premier facility for accelerator research and development, offering scientists and industry a unique opportunity to transform early-stage concepts into tested, high-impact technologies.

Real world impact

Professor Deepa Angal-Kalinin, CLARA Project Lead, said:

“Reaching 250 MeV is a tremendous achievement for the CLARA team and a major milestone for accelerator science in the UK. It reflects years of dedication, collaboration, and innovation. We are now excited to look ahead to CLARA’s future as a full user facility — a place where novel accelerator ideas will become reality, driving real-world impact.”

Learn more about CLARA here https://www.astec.stfc.ac.uk/Pages/CLARA.aspx