Characterization of a High-Brightness, Laser-Cooled Li⁺ Ion Source

Ion sources based on laser cooling have recently provided new pathways to high-resolution microscopy, ion milling, and ion implantation. Here, we present the design and detailed characterization of ⁷Li magneto-optical trap ion source (MOTIS) with a peak brightness of 1.3 x 10⁵ A m^-2 sr^-1 eV^-1 and a maximum continuous current of 1.16 ± 0.06 nA. These values significantly surpass previous Li MOTIS performance benchmarks. Using simple models, we discuss how the performance of this system relates to fundamental operating limits. This source will support a range of projects using lithium ion beams for surface microscopy and nanostructure characterization, including Li⁺ implantation for studies of ionic transport in energy storage materials.