Low-energy electron diffraction system using a position-sensitive detector

A low-energy electron diffraction (LEED) system using a position-sensitive detector is described. The design requirements for LEED observations are outlined. Most of these requirements are realized in a system incorporating a miniature, movable electron gun and a position-sensitive detector of the resistive anode type, interfaced to a computer. This system has been used to make 128×128 channel digital records of LED patterns. The speed of data acquisition is limited by the detector hardware and is 20 kHz. Records of good quality (0.1° instrumental angular resolving power) can be made by counting 5×105 electrons. Illustrative applications to silicon and tungsten crystal surfaces and prospects for improving the system are described.