The first electrons produced at an energy of 2 gigaelectronvolts (GeV) using laser-plasma acceleration are reported in Nature Communications this week. The result marks an important step in the development of laser-based table-top particle accelerators, which could bring work to generate X-rays - currently carried out in large facilities - in to the laboratory.
Particle accelerators have proven an important technology for many branches of science, particularly as they produce X-rays that can be used for biological, chemical, or materials research. But the usual synchrotrons or linear accelerators are large national facilities on kilometre length scales. Laser-plasma accelerators, on the other hand, can accelerate electrons to similar energies as synchrotrons over just a few centimetres. These alternative schemes use an intense laser pulse to create an electric field in plasma that subsequently drives electrons to high speeds and high energies. Up to now, the highest energies measured were around 1 GeV.
Michael Downer and colleagues utilise new high-power laser technology to increase the energy achievable up to 2 GeV. The energy spread of the accelerated electrons is very narrow, making them suitable for producing narrow bandwidth X-rays. The experimental parameters achieved with the new system are suitable for potential table-top X-ray sources or possible future particle colliders.