CERN is synonymous with accelerators, designed to boost particles to close to the speed of light. But what if you want to slow down a particle and hold it in place while you study it? Particle traps are devices that use electromagnetic fields to suspend particles – macroscopic or elementary – in stasis long enough to do so. At CERN, experiments such as GBAR use ion traps to capture antihydrogen ions for research. In the case of antimatter, it is particularly important to use electromagnetic fields in vacuum chambers so that the antiparticles do not come into contact with normal matter – if they were to do so, they would annihilate instantly in a small burst of energy.