A ring the size of a dinner plate made an electron beam run in circles. Its diameter is 22 centimeters, and a full turn takes just 4.7 nanoseconds. To put that in perspective: in one second, such an electron would complete more than two hundred million laps.

To get the particles inside, the team used a short electrical pulse lasting 140 nanoseconds. It acted like a sharp shove that flips a marble into a groove. A detector made of scintillating fibers picked up a signal five times stronger than the background noise, and it persisted for over a microsecond. That means the beam really stayed on its orbit instead of falling apart right away.

When the magnetic field holding the beam was slightly adjusted, the region where the electrons circled shifted. This matched computer simulations. That agreement is like a signature confirming that beam storage actually works.

Now these miniature rings could be used for ultra-precise measurements. The more compact the device, the easier it is to fit into a lab, and the faster the particles pick up speed. This paves the way for new experiments where every billionth of a second matters.