Austin, TX--Physicists at The University of Texas at Austin (UT Austin) have built a tabletop particle accelerator that now can accelerate about half a billion electrons to 2 GeV over a distance of about 1 in.
"Until now that degree of energy and focus has required a conventional accelerator that stretches more than the length of two football fields. It's a downsizing of a factor of approximately 10,000," says Mike Downer, professor of physics at UT Austin's College of Natural Sciences. The conventional accelerators he speaks of cost hundreds of millions of dollars to build.
The results, which were published in Nature Communications, mark a major milestone in the advance toward the day when multi-gigaelectronvolt laser plasma accelerators are standard equipment in research laboratories around the world.
Downer expects 10 GeV accelerators of a few inches in length to be developed within the next few years, and he believes 20 GeV accelerators of similar size could be developed within a decade.
Downer notes that the electrons from the current 2 GeV accelerator can be converted into hard x-rays as bright as those from large-scale facilities. He believes that with further refinement they could even drive an x-ray free electron laser (FEL).
"The x-rays we'll be able to produce are of femtosecond duration, which is the time scale on which molecules vibrate and the fastest chemical reactions take place," says Downer. "They will have the energy and brightness to enable us to see, for example, the atomic structure of single protein molecules in a living sample."
Downer and his colleagues used the Texas Petawatt Laser, which enabled them to use gases that are much less dense than those used in previous experiments.