Set to take particle accelerator technology to an entirely new level, researchers have recently discovered an entirely new means of accelerating electrons. And, quite incredibly, the group allege the new technique to be capable of achieving ten times the rate of acceleration of today’s conventional methods. It’s thought that, in due course, their work could spark the development of portable X-ray scanners, alongside cheaper particle accelerators.
Accelerator on a Chip
The team’s findings were published in the latest edition of the journal Nature, and involved scientists from the United States Department of Energy’s SLAC National Accelerator Laboratory and Stanford University.
When reaching its optimum potential, the latest “accelerator on a chip” could rival the accelerating capabilities of the SLAC’s linear accelerator. Putting this into perspective, the accelerating power that this two-mile-long linear accelerator can achieve is equivalent to what the “accelerator on a chip” can muster, within a mere 100 feet. Not only this, the new system delivers one million more electron pulses, every second.
Current particle accelerators harness the power of microwaves to amplify the energy of electrons. Particles are accelerated in two principal stages. Initially, they are accelerated to the speed of light. Beyond this, however, any additional attempt to increase acceleration simply elevates particle’s energy, but not its speed.
During the Stanford researchers’ experiment, the team implemented a system that uses a traditional accelerator to first excite the electrons to huge speeds, and then funneled these electrons into a 0.5 micron tall channel, within “a fused silica glass chip,” the length of half a millimeter. The channel possesses a series of nanoscale ridges; once an infrared laser is beamed along the ridge pattern, electrical fields are produced, which interact with the passing electrons and amplify their energy even further.
The team’s preliminary demonstration managed to ramp up electrons to an acceleration gradient of 300 million electronvolts (eV) per meter, with the gradient a measure of the amount of energy gained per unit length; this represents ten times the acceleration that can be obtained via use of the SLAC linear accelerator.
Robert Byer, a Stanford professor, who was working on the research endeavors, suggested that one of the team’s main objectives was to increase this acceleration gradient by over a triple, in a bid to achieve a whopping one billion electronvolts per meter.
Meanwhile, Joel England, a laser scientist at SLAC, explained how scientists were always trying to find ways of accelerating tiny particles using lasers, ever since the technology’s inception. During an interview, England spoke briefly about the fabrication process:
“In this case, we are using the same techniques that are used by the silicon microchip industry. Going from large microwave sources and copper cavities to small micron-scale structures, which are fabricated using the same sorts of techniques that are used for integrated chips.”
The full interview with England can be listened to in the following clip:
Portable X-Ray Imaging
The team confess that much more work will need to be conducted to get the electrons up to their initial speed, before they enter the group’s new device. However, these early results do seem promising and could pave the way for more compact, cheaper particle accelerators.
England highlighted some of the other potential benefits of their work:
“… eventually it would substantially reduce the size and cost of future high-energy particle colliders for exploring the world of fundamental particles and forces… 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.”
Byer suggests that smaller, portable X-ray equipment could result from the application of such technology. This could offer improved medical treatment for people injured in remote areas, and during combat, whilst driving down the costs of imaging devices applied in clinical settings.
Ultimately, the Stanford team’s “accelerator on a chip” innovation could be destined to offer research and medical industries fantastic, new opportunities, paving the way for cheaper and more compact technological solutions.
The following YouTube clip indicates how the accelerator on a chip uses the laser light to boost an electron’s energy:
By: James Fenner