Electron Ray Tracing in a Cylindrical Defector Analyzer for Field Emission Spectroscopy

Field-emission spectroscopy (FES) is a technique that acquires an energy spectrum of the electrons emitted from a field emitter. A cylindrical deflector analyzer (CDA) is often used for FES. Assuming that the electric field in the CDA is an ideal cylindrical field, it is known that the optimum deflection angle is 127°. In fact, there is a deviation from an ideal cylindrical field in the CDA. In particular, a fringing field occurring at the vicinity of entrance and exit of slits is not negligible. Therefore, herein, we performed three-dimensional (3D) electric field calculations and ray tracing using a 3D boundary charge method (BCM) that we developed previously. Using this approach, the CDA can be optimized to improve the energy resolution of FES.