Adaptable platform for trapped cold electrons, hydrogen and lithium anions and cations

Abstract

Cold cations, electrons and anions are ubiquitous in space, participate in star formation chemistry and are relevant to studies on the origin of molecular biology homochirality. We report on a system to generate and trap these species in the laboratory. Laser ablation of a solid target (LiH) facing a sublimating Ne matrix generates cold electrons, anions, and cations. Axial energy distributions (of e$^-$, H$^\pm$ and Li$^\pm$) peaked at 0-25 meV are obtained in a Penning trap at 90 mT and 0.5 eV barrier. Anions can be guided and neutralized with low recoil energy by near-threshold photodetachment. An immediate prospect for this H$^-$ source is to load hydrogen atoms into the ALPHA antihydrogen trap at CERN towards direct spectroscopic comparison of both conjugated species beyond 13 significant figures. The production is potentially scalable and adaptable to different species including deuterium and tritium, relevant for neutrino mass and fusion research.