Breakthrough in antimatter manufacturing | CERN

In a paper printed immediately in Nature Communications, researchers on the ALPHA experiment at CERN’s Antimatter Factory report a brand new approach that enables them to supply over 15 000 antihydrogen atoms – the only type of atomic antimatter – in a matter of hours.

“These numbers would have been considered science fiction 10 years ago,” stated Jeffrey Hangst, spokesperson for the ALPHA experiment. “With larger numbers of antihydrogen atoms now more readily available, we can investigate atomic antimatter in greater detail and at a faster pace than before.”

To create atomic antihydrogen (a positron orbiting an antiproton), the ALPHA collaboration should produce and lure clouds of antiprotons and positrons individually, then cool them down and merge them in order that antihydrogen atoms can kind. This course of has been refined and steadily improved over a few years. But now, utilizing a pioneering approach to chill the positrons, the ALPHA group has elevated the speed of manufacturing of antihydrogen atoms eightfold.

This spectacular advance within the manufacturing price is all all the way down to how the positrons are ready. First, the positrons are collected from a radioactive type of sodium and contained in what is named a Penning lure, the place fine-tuned electromagnetic fields maintain the antiparticles in place. However, they don’t stay nonetheless. Like a tiger in a zoo, the positrons circle their cage, inflicting them to lose power. This cools the cloud of positrons, however not sufficient for them to effectively merge with the antiprotons to kind antihydrogen atoms. So, the ALPHA group lately tried a brand new method, which was so as to add a cloud of laser-cooled beryllium ions to the lure in order that the positrons would lose power in a course of referred to as sympathetic cooling.

This acquired the positron cloud all the way down to a temperature of round -266 °C, making it more likely to kind antihydrogen atoms when blended with the antiprotons. This method allowed over 15 000 antihydrogen atoms to be accrued in below seven hours. To put this into perspective, it took a earlier experiment 10 weeks to build up the 16 000 antihydrogen atoms required to measure the spectral construction of antihydrogen with unprecedented precision. “The new technique is a real game-changer when it comes to investigating systematic uncertainties in our measurements.  We can now accumulate antihydrogen overnight and measure a spectral line the following day”, stated Niels Madsen, deputy spokesperson for ALPHA and chief of the positron-cooling undertaking.

Using this method for cooling positrons, the ALPHA experiment produced over 2 million antihydrogen atoms over the course of the experimental runs of 2023–24. And this 12 months, the researchers are making use of the unprecedented numbers of antihydrogen atoms to check the impact of gravity on antimatter as a part of the ALPHA-g experiment. This approach will permit much more exact measurements to be made and make it doable to probe deeper into the properties and behavior of atomic antimatter.