A high-resolution low-energy electron diffraction instrument

A high-resolution LEED system with optimum operating parameters for use below 100 eV has been designed and tested. A field-emission-based electron gun with an angular divergence of 2 mrad, and a large sample detector distance of 150 mm provide the major improvements in resolution. Measured beam widths (Δk/2π FWHM) for both specular and nonspecular beams are approximately 0.002 Å−1 in the energy range of 50–100 eV.