Cryogenic Penning-Trap Apparatus for Precision Experiments with Sympathetically Cooled (Anti)Protons

Current precision experiments with single (anti)protons to test CPT symmetry progress at a rapid pace, but are complicated by the need to cool particles to sub-thermal energies. We describe a cryogenic Penning-trap setup for 9Be+ ions designed to allow coupling of single (anti)protons to laser-cooled atomic ions for sympathetic cooling and quantum logic spectroscopy. We report on trapping and laser cooling of clouds and single 9Be+ ions. We discuss prospects for a microfabricated trap to allow coupling of single (anti)protons to laser-cooled 9Be+ ions for sympathetic laser cooling to sub-mK temperatures on ms time scales.