Researchers at CERN have gotten comfortable with antimatter — so comfortable, in fact, they’re planning to load a billion antimatter particles into a van for a quick field trip. Transporting the highly volatile antiprotons could help scientists understand the inner workings of neutron stars, but that’s not related to the antimatter itself. In this case, CERN intends to use antimatter as a tool to probe exotic atomic nuclei.
CERN has been studying antimatter for years, and we have a reasonably good understanding of its properties. All particles of matter have antiparticle counterparts like the antiproton, which has the same mass as a proton, but opposite charge and spin. It’s difficult to contain antimatter for study because you can’t store it anyplace. Every container in the world is made of matter, and antimatter annihilates instantly when it comes in contact with matter. CERN is going to stick a cloud of antimatter in a van, though.
Transporting antimatter is going to be a challenge, but they’re not just driving around with antimatter for the sake of doing it. Researchers want to use antiprotons to study the rare radioactive atomic nuclei produced in another CERN facility called ISOLDE. You need both the antimatter and the radioactive nuclei in the same place at the same time, so one of them has to move. However, the ISOLDE nuclei are very short-lived, so transporting them is out of the question. Thus, it’s antimatter in a van.
The team is currently designing and testing the equipment that will contain the antimatter for the short trip — it’s just a few hundred meters, but it might as well be a light year if you don’t have the right technology to store antiprotons. Scientists plan to capture the antiprotons in an electromagnetic field and cool them to within four degrees of absolute zero. That may allow them to reach the goal of storing 1 billion antiprotons, which would be orders of magnitude more than any other experiment.
Remember, this is all about understanding neutron stars. These collapsed stars are especially perplexing celestial objects. It’s difficult to understand the physics underpinning these ultra-dense balls of neutrons, but radioactive atomic nuclei can be a good stand-in. Because these particles have more than the stable number of neutrons, they create an “extended halo” that effectively boosts the size of the nucleus. These same forces are believed to be at work on a larger scale in neutron stars.
The researchers plan to observe how the radioactive nuclei behave when annihilated by antimatter. Because this process is so fast, even incredibly unstable nuclei can be probed. This may help scientists understand the way neutrons behave at high densities. It’ll be a few years before we get any answers, though. CERN estimated it’ll take four years to design the containment vessel. Experiments are currently scheduled for 2022.
CERN Determines the Color of Antimatter
As part of an effort to better understand antimatter, researchers at CERN have conducted experiments to examine the "color" of antihydrogen. So far, it looks surprisingly like matter version.