For the first time, scientists have created a silicon chip that can accelerate electrons at a fraction of the velocity. The most massive accelerators using an infrared laser to deliver, in less than a hair’s width. Sort of energy boost that takes microwaves many feet.
On a hillside above Stanford University, the SLAC National Accelerator Laboratory operates a scientific instrument nearly 2 miles long. In this giant accelerator, a stream of electrons flows through a vacuum pipe. Bursts of microwave radiation nudge the particles ever-faster forward until their velocity approaches the speed of light, creating a powerful beam that scientists from around the world probe the atomic and molecular structures of inorganic and biological materials.
For the first time, scientists at Stanford and SLAC have created a silicon chip that can accelerate electrons at a fraction of the velocity of that massive instrument using an infrared laser to deliver in less than a hair’s width the sort of energy boost that takes microwaves many feet.
Writing in the Jan. 3 issue of Science, a team led by electrical engineer Jelena Vuckovic explained how they carved a nanoscale channel out of silicon, sealed it in a vacuum and sent electrons through this cavity while pulses of infrared light to which silicon is as transparent as glass is to visible light were transmitted by the channel walls to speed the electrons along.
The accelerator-on-a-chip demonstrated in Science is just a prototype, but Vuckovic said its design and fabrication techniques can be scaled up to deliver particle beams accelerated enough to perform cutting-edge experiments in chemistry. Materials science and biological discovery that don’t require the power of a massive accelerator.