Tabletop Particle Accelerator

Black holes and pulsars emit dense jets of particles that are made of electrons and positrons (the antiparticle of the electron). But many important and basic features of the jets remain unclear: What is their precise particle makeup? How much energy do they contain? How do the particles in the jets interact in the low-density environment of outerspace? The main difficulty in answering these questions is that astronomical systems can only be measured indirectly: the closest jet is almost 10²⁴ miles away. As Gianluca Sarri from The Queen’s University of Belfast, Northern Ireland, and colleagues report in Physical Review Letters, a new tabletop method for generating electron-positron streams could bring measurements closer to home by enabling the scaled-down reproduction of matter-antimatter flows in the lab.