Where's the antimatter? CERN gears up to ship antimatter across Europe A portable containment device that can be dropped on a truck. John Timmer – May 19, 2025 12:13 pm | 14 A truck loaded with some protons drove around the CERN campus recently. Credit: Sean Pavone A truck loaded with some protons drove around the CERN campus recently. Credit: Sean Pavone Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only   Learn more There's a lot of matter around, which ensures that any antimatter produced experiences a very short lifespan. Studying antimatter, therefore, has been extremely difficult. But that's changed a bit in recent years, as CERN has set up a facility that produces and traps antimatter, allowing for extensive studies of its properties, including entire anti-atoms. Unfortunately, the hardware used to capture antiprotons also produces interference that limits the precision with which measurements can be made. So CERN decided that it might be good to determine how to move the antimatter away from where it's produced. Since it was tackling that problem anyway, CERN decided to make a shipping container for antimatter, allowing it to be put on a truck and potentially taken to labs throughout Europe. A shipping container for antimatter The problem facing CERN comes from its own hardware. The antimatter it captures is produced by smashing a particle beam into a stationary target. As a result, all the anti-particles that come out of the debris carry a lot of energy. If you want to hold on to any of them, you have to slow them down, which is done using electromagnetic fields that can act on the charged antimatter particles. Unfortunately, as the team behind the new work notes, many of the measurements we'd like to do with the antimatter are "extremely sensitive to external magnetic field noise." In short, the hardware that slows the antimatter down limits the precision of the measurements you can take. The obvious solution is to move the antimatter away from where it's produced. But that gets tricky very fast. The antimatter containment device has to be maintained as an extreme vacuum and needs superconducting materials to produce the electromagnetic fields that keep the antimatter from bumping into the walls of the container. All of that means a significant power supply, along with a cache of liquid helium to keep the superconductors working. A standard shipping container just won't do. So the team at CERN built a two-meter-long portable containment device. On one end is a junction that allows it to be plugged into the beam of particles produced by the existing facility. That junction leads to the containment area, which is blanketed by a superconducting magnet. Elsewhere on the device are batteries to ensure an uninterrupted power supply, along with the electronics to run it all. The whole setup is encased in a metal frame that includes lifting points that can be used to attach it to a crane for moving around. To confirm it all works, the team loaded it up with some protons (which are notably easier to produce). Two internal cranes in the facility, along with a heavy-duty four-wheeled cart, moved the container to a loading dock, where it was transferred to a truck and taken for a spin around the CERN campus at Meyrin. Based on the map included in the paper describing the work, it appears that the protons started out in France but briefly crossed the border into Switzerland. All told, they traveled just under four kilometers and reached speeds of over 40 km/hour. Hitting the road Overall, the hardware stayed cold, generally at a bit over five Kelvin. The exception was when the system was reconnected to the antimatter source hardware and the system reconnected to the electrical system at CERN. While those actions show up as temperature spikes, the superconducting magnets remained well under seven Kelvin. An accelerometer was in place to track the forces experienced by the hardware while the truck was moving. This showed that changes in the truck's speed produced turbulence in the liquid helium, making measurements of its presence unreliable. Levels had dropped from about 75 percent of maximum to 30 percent by the time the system was reconnected, suggesting that liquid helium presents the key limiting factor in shipping. Measurements made while the system was in transit suggest that the whole process occurred losslessly, meaning that not a single proton escaped during the entire transport. All that's missing now is another experiment at CERN that the antimatter can be delivered to. Presumably, the team is looking for lab space in a building with little in the way of stray electromagnetic fields. But the team has bigger goals in mind. There's a facility being built in Düsseldorf, Germany, for antiproton experiments, nearly 800 kilometers and eight hours away by road. If the delivery can be made successfully—and it appears we are just a liquid helium supply away from getting it to work—the new facility in Germany should allow measurements with a precision of over 100 times better than anything that has been achieved at CERN. Nature, 2025. DOI: 10.1038/s41586-025-08926-y  (About DOIs). John Timmer Senior Science Editor John Timmer Senior Science Editor John is Ars Technica's science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots. 14 Comments