Improvement of spectrometer energy resolution for high-resolution photoelectron spectroscopy

For high-energy-resolution photoelectron spectroscopy using synchrotron radiation, the energy resolution of a commercial compact photoelectron spectrometer (hemispherical concentric spectrometer) was improved by reducing the size of the entrance and detector slits and optimizing the operation conditions of the lens voltage. Under the optimized conditions, ray-tracing simulations show that severe spectral intensity decreases can be avoided. An energy resolution of 6.2 meV and a resolving power of 8100 at a kinetic energy of 50 eV were experimentally obtained.