DESIGN OF A SPECTROSCOPIC LOW-ENERGY ELECTRON-MICROSCOPE

The instrumental design aspects of a spectroscopic low-energy electron microscope for the direct imaging of chemical, topographic and structural features on surfaces are presented. This instrument extends the LEEM concept to include energy-resolved imaging of secondary, Auger and X-ray emissions with enhanced resolution and collection efficiency. Key new elements include a triode magnetic cathode lens, a prism array separator magnet, a decelerating hemispherical energy analyzer, and a high-quantum-efficiency intensifier. Mathematical techniques for the optimization of viewing conditions are reviewed, and the goals of pending performance tests are given.