BASE experiment at CERN succeeds in transporting antimatter
The experiment successfully transported a trap filled with antiprotons across CERN’s main site, a remarkable first step towards delivering antimatter to other European laboratories
24.03.2026 |
This news is based on a CERN press release.
On 24 March 2026, in a world first, a team of scientists from the BASE experiment at CERN, including GSI researchers, successfully transported a trap filled with antiprotons in a truck across the Laboratory’s main site. The team managed to accumulate a cloud of antiprotons in an innovative portable cryogenic Penning trap, then disconnect it from the experimental facility, load it onto a truck and continue experiment operation after transport. This is a remarkable achievement, given that antimatter is very difficult to preserve, as it annihilates upon contact with matter. The GSI Department for Atomic, Quantum and Fundamental Physics is a long-standing member of the BASE collaboration. Furthermore, GSI has supported the project by delivering high-precision components manufactured in its mechanical workshop.
Antimatter is a naturally occurring class of particles that is almost identical to ordinary matter except that the charges and magnetic properties are reversed. According to the laws of physics, the Big Bang should have produced equal amounts of matter and antimatter. These equal-but-opposite particles would have quickly annihilated with each other, leaving an empty Universe. However, our Universe contains dominantly matter, and this imbalance has baffled scientists for decades. Physicists suspect that there are hidden differences that can explain why matter survived and antimatter all but disappeared.
To deepen our understanding of antimatter, the BASE collaboration aims to precisely measure the properties of antiprotons, such as their intrinsic magnetic moment, and then compare these measurements with those taken with protons. But they now face a problem: “The machines and equipment in CERN’s ‘antimatter factory’, where BASE is located, generate magnetic field fluctuations that limit how far we can push our precision measurements,” explains Stefan Ulmer, spokesperson of BASE. “If we want to get a deeper understanding of the fundamental properties of antiprotons, we need to move out.”
CERN’s “antimatter factory” is the only place in the world where antiprotons can be produced, stored and studied. Two decelerators, the Antiproton Decelerator (AD) and the Extra Low ENergy Antiproton ring (ELENA), provide several experiments with low energy antiprotons – the lower their energy, the easier they can be stored to be studied. Among these experiments, BASE has long standing records of containing antiprotons for more than one year, and the experiment invented this pioneering approach to move on to the next stage: move to offline space for more precise experiments and also share them with others. That’s why they developed the BASE-STEP trap: an apparatus designed to store and transport antiprotons.
“Our aim with BASE-STEP is to be able to trap antiprotons and deliver them to our precision laboratories at a dedicated space at CERN, Heinrich Heine University Duesseldorf, Leibnitz University Hannover, and maybe other laboratories, capable of performing very high-precision antiproton measurements, which unfortunately is not possible in the antimatter factory”, explains Christian Smorra, the leader of BASE-STEP. “We validated the feasibility of the project with protons last year, but what we achieved today with antiprotons is a huge leap forward towards our objective.”
BASE-STEP is small enough to be loaded onto a truck and fit through ordinary laboratory doors, and it can resist to the bumps and vibrations during transport. The current apparatus — which includes a superconducting magnet, liquid helium cryogenic cooling, power reserves, and a vacuum chamber that traps the antiparticles using magnetic and electric fields — weighs 1000 kilograms: much more compact than BASE or any existing system used to study antimatter.
This world premiere is a test, the aim being to transport antiprotons to other European laboratories, for example at Heinrich Heine University Duesseldorf, where very high precision measurements of the antiproton properties could be performed.
"To reach our first destination – our dedicated precision laboratory at HHU in Germany – would take us at least 8 hours," says Christian Smorra. "This means, we’ll have to keep the trap’s superconducting magnet at a temperature below 8.2 K for that long. So, instead of liquid helium, which can run out, we’d need to have a generator to power a cryocooler on the truck. We are currently investigating this possibility.” But still, the greatest challenge remains once at the destination: to transfer the antiprotons into the experiment without them vanishing.
“Transporting antimatter is a pioneering and ambitious project, and I congratulate the BASE collaboration on this impressive milestone. We are at the beginning of an exciting scientific journey that will allow us to further deepen our understanding of antimatter,” says CERN Director for Research and Computing, Gautier Hamel de Monchenault.
“Congratulations to the BASE collaboration on this fantastic achievement,” says Thomas Nilsson, Scientific Managing Director of GSI and FAIR, and continues: “This significant technological breakthrough also makes it possible to transport highly charged heavy ions—which are currently available for ion trap experiments only at the HITRAP facility at GSI—to other research institutes for fundamental tests in quantum physics.” (CERN/LW)
