PALLAS Achieves Electron Beam in fully beamline integrated Compact Dual Gas Cell Configuration

The PALLAS project (Prototyping Accelerator based on Laser pLASma technologies) at IJCLab (Irène Joliot-Curie Laboratory of Physics) has produced its first electron beam in a fully beamline-integrated double gas cell. This world-first compact configuration marks a significant milestone in advancing next-gen laser-plasma wakefield acceleration technologies.

Developed in collaboration with LLR and LP2I Bordeaux of CNRS Nuclear and Particles Physics and Université Paris-Saclay, PALLAS directly supports EuPRAXIA, the first European research infrastructure dedicated to plasma accelerators. Also, IJCLab plays a central role in the PACRI project as the main French contributor. This consortium of 26 European partners is developing plasma accelerators as sustainable solutions for reducing the carbon footprint of research infrastructures.

PALLAS accelerator beamline view (left image); structured gas target prototype tested at IJCLab.

During the testing the team accelerated electrons up to 160 MeV using a plasma cell just millimetres long. The major breakthrough involved producing an electron beam in a compact dual gas cell designed and manufactured at IJCLab, directly integrated into the beamline (read more about it: here). This device enables precise control of gas density profiles and species composition over sub-millimetre lengths, directly supporting EuPRAXIA's goal of building the first European plasma accelerator infrastructures.

The LASERIX laser at Université Paris-Saclay, affiliated with IJCLab since 2020, delivers 50-terawatt ultra-short pulses lasting 40 femtoseconds. These pulses propagate through helium and nitrogen mixtures, creating plasma where electrons are accelerated by the wakefield. As a part of CNRS, the main French contributor to PACRI, IJCLab is advancing laser-plasma technology that offers acceleration gradients up to 1,000 times higher than conventional systems, enabling far more compact facilities for fundamental research, medicine, and industry. Platforms like PALLAS are essential for improving beam stability and quality before integration into large-scale infrastructures or hospital environments.