This could dramatically shrink particle accelerators for science and medicine applications. “We still have a number of challenges before this technology becomes practical for real-world use, but eventually it would substantially reduce the size and cost of future high-energy particle colliders for exploring the world of fundamental particles and forces,” said Joel England, the SLAC physicist who led the experiments. “It could also help enable compact accelerators and X-ray devices for security scanning, medical therapy and imaging, and research in biology and materials science.”
Because it employs commercial lasers and low-cost, mass-production techniques, the researchers believe it will set the stage for new generations of "tabletop" accelerators. At its full potential, the new “accelerator on a chip” could match the accelerating power of SLAC’s 2-mile-long linear accelerator in just 100 feet (of stacked devices), and deliver a million more electron pulses per second.
The initial prototype achieved an acceleration gradient, or amount of energy gained per length, of 300 million electronvolts per meter. That's roughly 10 times the acceleration provided by the current SLAC linear accelerator.
“Our ultimate goal for this structure is 1 billion electronvolts per meter, and we’re already one-third of the way in our first experiment,” said Stanford Professor Robert Byer, the principal investigator for this research.
Particles are generally accelerated in two stages. First they are boosted to nearly the speed of light. Then any additional acceleration increases their energy, but not their speed; this is the challenging part. In the accelerator-on-a-chip experiments, electrons are first accelerated to near light-speed in a conventional accelerator. Then they are focused into a tiny, half-micron-high channel within a fused silica glass chip just half a millimeter long. The channel had been patterned with precisely spaced nanoscale ridges. Infrared laser light shining on the pattern generates electrical fields that interact with the electrons in the channel to boost their energy.
Turning the accelerator on a chip into a full-fledged tabletop