A versatile data acquisition system for low‐energy electron diffraction

We have developed a system for rapid data acquisition from low‐energy electron diffraction (LEED) patterns. The essential components of the system are a sensitive silicon intensified target video camera, a commercial video interface, and a PDP 11/23 microcomputer. The system is designed to acquire up to ten diffraction spot intensities and profiles (total) in a short time relative to the time scales of typical surface reactions. The data acquisition system is used in conjunction with standard Varian■ four‐grid LEED optics in an ultrahigh vacuum chamber. The abilities of the system with respect to versatility, speed, linearity, and signal‐to‐noise are demonstrated, and data from a study of oxygen chemisorption on Pd(100) are presented.