Plasma and trap-based techniques for science with positrons

The study of antimatter has been greatly advanced recently through the development of traps, which use plasma-based techniques. This article reviews the use of traps for positrons to study antimatter physics including positron-matter interactions, electron-positron plasmas, anti-hydrogen and dynamics of antimatter in gravitational fields. In recent years, there has been a wealth of new science involving low-energy antimatter (i.e., positrons and anti-protons) at energies ranging from 10[sup 2] to less than 10[sup -3] eV. This article focuses on the advances made in this area using positrons. Methods are described to produce intense sources of positrons and to efficiently slow the typically energetic particles thus produced. The review concludes with a brief summary and a list of outstanding challenges. Finally, the procedures developed to deliver tailored pulses and beams (e.g., in intense, short bursts, or as quasi-mono-energetic continuous beams) for specific applications are reviewed.