We have developed a coaxially symmetric mirror electron energy analyzer with a high sensitivity, which was originally proposed by Kai Siegbahn in 1997. The analyzer, however, had a weak point; i.e. the performance is degraded by disturbance of the electric field near the end plates. We have improved the point by adopting compensation electrodes. Simulation with SIMION 3D version 7.0 predicts that the energy resolution (E/ΔE, FWHM) would be 300 for a pointed electron source and a solid angle of 1.2 sr. This value is about 3 times as much as the predicted value for the cylindrical mirror analyzer (CMA) used in previous EICO apparatuses. The resolution of the electron energy analyzer was obtained at UVSOR BL-2B1 by measuring an Au : 4f photoelectron spectrum of a gold film. The actual energy resolution was evaluated to be 110-130. Some improvements and applications to coincidence spectroscopy are also described.
