Antiproton physics in the ELENA era

The programme of physics with low-energy antiprotons at CERN, the European Particle Physics Laboratory, has a long history, beginning with the inauguration of the Low Energy Antiproton Ring (LEAR) in 1982 [1]. That machine produced antiprotons decelerated to kinetic energies of a few MeV, an achievement made possible due to advances in techniques that enabled cooling of charged particles held in storage rings [2,3]. Pioneering experiments to trap and cool antiprotons to meV energies were carried out at LEAR [4,5] and a landmark achievement was reached in 1995, when the first nine atoms of antihydrogen were observed by the PS210 experiment [6]. A short lapse in the availability of low-energy antiprotons followed this success, as LEAR …