Mini Antimatter Accelerator Could Unravel Mysteries of Dark Matter

Simulation of groups of positrons being concentrated into a beam and accelerated. Imperial College London

Scientists have developed a technique that could be capable of accelerating antimatter in a space around a thousand times smaller than what current accelerator facilities require, according to a study published in the Physical Review Journal for Accelerators and Beams.

The new approach could boost the science of exotic particles and help researchers to unravel some of the biggest mysteries in physics, such as the nature of hypothetical dark matter and dark energy, as well as the properties of the Higgs boson—an elementary particle which gives all other particles mass.

Particle accelerators such as the Large Hadron Collider (LHC) at CERN in Switzerland and the Linac Coherent Light Source (LCLS) at Stanford University are designed to speed up elementary particles which make up atoms and are not composed of any smaller particles—protons and electrons, for example.

The LHC, for example, can smash together these tiny bits of matter to produce particles that are even more elementary, like the Higgs boson. The LCLS, on the other hand, accelerates particles to produce X-ray laser light that scientists can use to image extremely fast and small processes, such as photosynthesis.

Facilities such as these have led to numerous valuable scientific insights, however, the accelerators use equipment that is at least 2 kilometers (1.2 miles) long in order to accelerate the particles to sufficient speeds.

Now, scientists from Imperial College London have come up with a method that could accelerate the antimatter version of electrons—known as positrons—in a set-up that would be just inches long. Antimatter is any material composed of the antiparticle to the corresponding particle of ordinary matter.

An accelerator based on the new technique would require a laser system that covers only around 25 square meters (269 square foot).

"This method makes antimatter accelerators quite compact, very inexpensive and widely affordable," Aakash Sahai, a physicist at Imperial and author of the study, told Newsweek. Currently, there are only a handful of antimatter accelerators around the world, he said, and these are "only accessible to large scientific collaborations through a very competitive process".

Moreover, these accelerators are exclusively used for highly specialized particle physics research. And unfortunately, because these facilities are inaccessible for most scientists, many small research teams in nations with lesser resources are unable to produce breakthrough science, he said.

"By making antimatter accelerator technology widely accessible to small physics labs, this method opens up the possibility for small research groups to answer their questions rapidly without depending upon big machines."

The researchers have modeled the new method using the properties of existing lasers and have planned experiments to test it, which will be conducted in the near future. If these tests, are successful, the technology could allow many more labs around the world to conduct antimatter acceleration experiments.

"The technologies used in facilities like the Large Hadron Collider or the Linac Coherent Light Source have not undergone significant advances since their invention in the 1950s. They are expensive to run, and it may be that we will soon have all we can get out of them," he said. "What is now only possible by using large physics facilities at tens of million-dollar costs could soon be possible in ordinary physics labs."

The team's method harnesses lasers and plasma—a gas of charged particles that is the fourth fundamental state of matter—to produce positrons and accelerate them, creating a beam.

The technique could be used to generate Higgs bosons at a higher rate than the LHC and, therefore, better study its properties. These experiments could also be used to search for undiscovered particles that are predicted to exist in a theory called "supersymmetry" which may be able to fill in some of the gaps in the Standard Model of particle physics.

In addition, the positron beams could be used to provide more sensitive testing of materials. Currently, X-rays or electron beams are used to check for faults in these materials. But positrons interact in a different way, which would improve the quality control process.

"In a few years, this technology could be used to detect defects in airline or spacecraft wings and engines, or in car engines, and even be used to produce much smaller cellphone chips than is currently possible," Sahai said. "Moreover, it will help many research groups worldwide in their quest to be the first to answer the fundamental questions of nature."

"Currently, scientists are looking to build new colliders to search for heavier particles, like the particles of dark matter and dark energy".

Physicists are already incorporating the latest method into these designs, Sahai said. Furthermore, he hopes that a working prototype of an accelerator based on the new technique can be produced within a couple of years.

This article has been updated to include additional comments from Aakash Sahai.