On 2 August 2017, the first 5.3 MeV antiproton beam coming from CERN’s Antiproton Decelerator (AD) circulated in the Extra Low ENergy Antiproton (ELENA) decelerating ring.

ELENA is the new decelerator for antimatter experiments. It has a circumference of just 30 meters and will be connected to the AD experiments to improve the conditions for typical antimatter experiments. The slower the antiprotons are (i.e. the less energy they have), the easier it is for the AD’s antimatter experiments to study or manipulate them. However, the AD decelerator can reliably only slow antiprotons down to 5.3 MeV, the lowest possible energy for a machine of this size. The much smaller ELENA ring will reduce this energy by 50 times, to just 0.1 MeV, opening up the possibility for additional experiments, such as GBAR. In addition, the density of the beams will be improved, thus increasing the efficiency with which the experiments can capture the antiprotons in their traps by a factor of 10 to 100. The new decelerator will also enable several experiments to receive antiproton beams simultaneously.

More information at cern.ch

The new deceleration ring ELENA will slow down antimatter particles further than ever to improve the efficiency of experiments studying antimatter. (Image: Maximilien Brice/CERN)