New lens system for surface vibrational spectroscopy at high impact energies

Abstract

The design, characterization, and performance of a new lens system which permits high-resolution electron energy-loss spectroscopy (EELS) studies at high energies is described. The lens system can be adapted to most existing EELS instruments and extends the impact energy range to 300 eV. Electron ray-tracing techniques are used to characterize operating modes of one of the more common EELS optics designs as well as the new lens configuration. The results presented in this paper demonstrate some limitations of matrix optics approaches and the applicability of electron ray-tracing techniques for characterizing the transmission properties, angular profiles, image sizes, and operating modes of EELS spectrometers.