GeV Acceleration in Only 3 Centimeters

Much of particle physics over the past century was made possible by machines that could accelerate particles up to energies of thousands of electronvolts (keV), then millions of electronvolts (MeV), and then billions (GeV). Possessing such high energies, beam particles can, when they smash into something, recreate for a short time a small piece of the early hot universe. Now the effort to impart more acceleration to particles over a short haul has taken a notable step forward. Physicists at the Lawrence Berkeley National Laboratory and the University of Oxford have accelerated electrons up to an energy of 1 GeV in a space of only 3 centimeters. The device used is called a laser wakefield accelerator since it boosts the electrons using potent electric fields set up at the trailing edge of a burst of laser light traveling through a plasma-filled cavity. Previously gradients as high as 100 GeV per meter had been attained, but the acceleration process could not be sustained to energies much above 200 MeV.

Leemans et al., Nature Physics, October 2006