Miniature Particle Accelerator Sets New Energy Record

The particle accelerator is one of the most complicated machines humans have ever made. It is the closest thing to a time machine, per Stephen Hawking. Just don’t try to put your head inside one! If you wonder what would happen, read Anatoli Bugorski’s story.

Around the world, there are thousands of particle accelerators, that they need to be regulated. Most are large facilities, like the famous CERN’s Large Hadron Collider (LHC).

But more compact and more affordable, mini particle accelerators have democratized research in many sciences.

While a large collider beams particles over thousands of miles of round rings, a mini accelerator does it over a few centimeters or even millimeters. But, there’s the energy level these compact accelerators can achieve.

Terahertz-Powered Mini Particle Accelerator

Based in Germany, DESY (Deutsches Elektronen-Synchrotron) is one of the world’s largest accelerator research centers.

A group of researchers from the Center for Free-Electron Laser Science (CFEL) at DESY has announced that their experimental mini accelerator had achieved record energy.

While large particle accelerators use long radio waves, mini particle accelerators require shorter wavelengths. DESY scientists turned to terahertz radiation and explored its potential in powering a new generation of compact particle accelerators.

Terahertz radiation lies between infrared and microwave frequencies. It is about a hundred times shorter than the waves currently used for particle accelerators. Meaning, the components of the accelerator themselves can be shrunk by a factor of one hundred.

If you can’t wrap your head around it, just imagine a mini LHC that fits on a tabletop.

“For the first time, a terahertz powered accelerator more than doubled the energy of the injected electrons. At the same time, the setup significantly improved the electron beam quality compared to earlier experiments with the technique.”

This experimental mini accelerator is an updated version of another device the DESY team had previously built, called STEAM (Segmented Terahertz Electron Accelerator and Manipulator). First, they compressed the incoming electron bunches from about 0.3 to 0.1 millimeters in length, and then accelerated these compressed bunches.

“This scheme requires control on the level of quadrillionths of a second, which we achieved,“ said Dongfang Zhang, co-author of the paper on the second STEAM device. “This led to a fourfold reduction of the energy spread and improved the emittance sixfold, yielding the best beam parameters of a terahertz accelerator so far.”

The results of the DESY experiment represent a significant step toward the practical implementation of lab-sized accelerators powered by terahertz waves. Biology, medical imaging, materials, particle physics, and many other fields of science would benefit from terahertz-powered accelerators. CERN itself is also developing such devices.