September 30, 2022

A particle accelerator that fits on a chip

Scientists at Stanford University and SLAC National Accelerator Laboratory have created a silicon chip that can accelerate electrons, albeit at a fraction of the velocity of standard particle accelerator, using an infrared laser.

In a regular accelerator, microwave bursts deliver the greatest possible acceleration. But microwaves measure 4 inches from peak to trough, while infrared light has a wavelength one-tenth the width of a human hair. That difference explains why infrared light can accelerate electrons in such short distances compared to microwaves. Therefore the chip’s physical features must be 100,000 times smaller than the copper structures in a traditional accelerator.

This prototype of accelerator-on-a-chip could 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. The researchers would want to accelerate electrons to 94 percent of the speed of light, or 1 million electron volts (1MeV). The prototype currently provides only a single stage of acceleration, and the electron flow would have to pass through around 1,000 of these stages to achieve 1MeV. (Phys.org)

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