A high resolution threshold electron spectrometer for use in photoionisation studies

Abstract

An electron spectrometer is described for use in threshold photoionisation studies. The spectrometer incorporates a penetrating field extractor stage, a 127 degrees cylindrical deflection analyser and an electrostatic lens system to match the two together. The high collection efficiency, resolution, transmission and sensitivity of the spectrometer are demonstrated with threshold photoionisation measurements in argon and helium. The spectrometer is also able to handle non-threshold photoelectrons. The high performance and ease of operation of the spectrometer suggest that it could be used as a general diagnostic tool on synchrotron VUV and soft X-ray beam lines.