Surfing a Laser Wave

Abstract

Particle accelerators are the behemoths of physics. The Stanford Linear Collider, for example, hurls electrons and positrons down a 2-mile-long tunnel before steering the particles into head-on collisions in the middle of a massive detector. It`s difficult to imagine shrinking this kind of machine to fit on top of a bench in a university laboratory. Advances in laser technology, however, have opened up the possibility of building a tabletop accelerator. Researchers can now generate and manipulate extremely short, immensely powerful laser pulses that instantly strip electrons from atoms to produce a plasma of charged particles. As demonstrated in recent experiments, the same pulses create electric fields strong enough to organize some of these electrons into a tight beam and accelerate them to high energies in just a few centimeters. This article discusses the development of the idea and the practical aspects of laser electron accelerators.