Low-energy single-electron detector with sub-micron resolution

Single-electron detectors are a key component of electron microscopes and advanced electron optics experiments. We present a YAG:Ce scintillator-based single-electron detector with a spatial resolution of 1 micrometer at an electron energy of 17 keV. Single-electron detection events are identified with an efficiency and purity larger than 0.8 at an electron energy of 17 keV, reaching 0.96 at 30 keV. We show that the detector enables electron diffraction studies with a sample-detector distance comparable to the mean free path of electrons at atmospheric pressure, potentially enabling atmospheric electron diffraction studies.