View of the Antiproton Decelerator (AD)

The AD is a ring composed of bending and focussing magnets that keep the antiprotons on track inside evacuated beam pipes, while strong electric fields slow them down. The spread in energy of the antiprotons and their deviation from their track is reduced by a technique known as “cooling”. Antiprotons are subjected to several cycles of cooling and deceleration until they are slowed down to around a tenth of the speed of light. The photo shows Tommy Ericsson, Head of the AD operations group, next to the ‘electron cooling’ device.