Scientists transport 92 antiprotons by road for first time, store them in vessel for over a month

Scientists succeeded in transporting antiprotons by road for the first time in a purpose-built trap loaded on a truck. The team from BASE collaboration, which realized this experiment, report that it was possible to store antiprotons in a mobile transport vessel for more than a month for the first time ever.

The team revealed that comparing protons – the positively charged components of an atomic nucleus – with antiprotons – their antimatter counterparts – is one of the most promising methods for seeking differences between matter and antimatter. Any identified difference in their mass or magnetic moment could point to the potential origin of the matter-antimatter asymmetry that can be observed in the cosmos.

92 trapped antiprotons have been transported

So-called ultra-high vacuum Penning traps enable such high-precision measurements of the protons and antiprotons confined in them. The BASE (Baryon Antibaryon Symmetry Experiment) research collaboration designed and now operates a trap of this kind – known as BASE-STEP – at CERN, or more precisely the “Antimatter Factory” (AMF) there. The AMF is the only facility worldwide where low-energy antiprotons can be produced, stored and studied, according to a press release.

“In recent years, we have already achieved precision measurements of the intrinsic magnetic moment of both types of particles with an accuracy of 0.3 ppb for protons and 1.6 ppb for antiprotons,” said Professor Stefan Ulmer, holder of the Chair of Quantum Technologies and Fundamental Symmetries at HHU. Ulmer is the founder and spokesperson of BASE, and co-author of the new study in Nature.

The study demonstrates the road transport of antiprotons trapped in BASE-STEP. Ninety-two trapped antiprotons have been transported outside the Antimatter Factory along a 7.5-km route without particle loss or measurable degradation of the trap vacuum. This achievement marks the starting point for a new era of antiproton precision measurements 8,12 in dedicated low-noise offline laboratory environments.

“We cannot improve the level of measurement accuracy any further at the AMF as facility operation causes magnetic-field fluctuations, which affect our measuring equipment,” said Dr Christian Smorra, BASE-STEP principal investigator and corresponding author of the study.

Scientists will transport antiprotons to another location with high-precision laboratory

“We can only find better conditions outside CERN. And so the idea of the mobile open BASE-STEP trap was born: We will transport the antiprotons to another location with a high-precision laboratory in order to achieve an at least 100-fold improvement in precision.”

One destination for the stored antiprotons is the high-precision laboratory currently being established at HHU by Ulmer’s team to enable comparison measurements of protons and antiprotons.

“We completed a successful dress rehearsal with the transport in March and were able to demonstrate that our idea works. Our next target is to make the trap sufficiently autonomous to allow a ten-hour transport from Geneva to Düsseldorf,” states Dr Smorra.