An Energy Modulated High Energy Resolution Electron Spectrometer

Abstract

A new cylindrical retarding potential difference type or energy modulated electron spectrometer has been constructed with high energy resolution. For energies greater than 1 eV the ratio of beam current I to energy spread FWHM, ΔE has been found to be approximately constant so that I/ΔE≃10⁻⁷ (A/eV) at about 20 eV. For electron energies from 0 to 1 eV the electron current increases with energy by about 10⁻⁷ A/eV for ΔE≃0.1 eV to the value given by the above expression. For energies above 1 eV the electron current is a very slowly varying function of energy. The energy resolution has been checked to 0.008 eV by studying the shape of the He⁻(²S_½) resonance at 19.3 eV in a transmission experiment. The over‐all performance of the spectrometer has been studied for electron energies from 0 to 60 eV in transmission experiments in He by studying structures in the electron scattering cross section.