For the first time, researchers have managed to simulate a fundamental process of cosmic particle acceleration in a laboratory: the first series of discoveries that will transform our understanding of cosmic rays. Now, scientists from the Universities of Birmingham and Chicago have created a tiny, 100-micrometre Fermi accelerator, in which mobile optical potential barriers collide with trapped atoms, in a partial replica of how cosmic particles pick up energy in space. The technique not only replicates cosmic ray behaviour but also sets a new benchmark in quantum acceleration technology.

Lab-Built Fermi Accelerator Using Cold Atoms Validates Cosmic Ray Theory and Advances Quantum Tech

As per findings published in Physical Review Letters, this fully controllable setup demonstrated particle acceleration through the Fermi mechanism first proposed by physicist Enrico Fermi in 1949. Long theorised to underlie cosmic ray generation, the process had never been reliably replicated in a lab. By combining energy gains with particle losses, researchers created energy spectra similar to those observed in space, offering the first direct validation of Bell’s result, a cornerstone of cosmic ray physics.

In Fermi acceleration, ultracold atoms are accelerated to more than 0.5 metres per second using laser-controlled barriers. Dr Amita Deb, a coauthor and researcher at the University of Birmingham, mentioned, ‘Our chimney is more powerful than conventional quantum nano-measurements, which are the best acceleration tools in the world so far, and while its simplicity and small size can be compelling, its lack of a theoretical speed limit is the most attractive feature.’ The ultracold atomic jets could be readily controlled with high precision in the subsequent experiments.

This progress means that, for the first time, complicated astrophysical events like shocks and turbulence can be studied in a laboratory, lead author Dr Vera Guarrera stated. This opens new avenues for high-energy astrophysics and also for applications in quantum wavepacket control and quantum chemistry.

Researchers plan to find out how different behaviour affects energy cutoffs and acceleration rates. A compact Fermi accelerator of this type could be a cornerstone for studies of fundamental physics and also connect to emerging technologies such as atomtronics.