Monte Carlo simulation of charged-particle-analyzer line shapes

Abstract

A Monte Carlo simulation method is presented for calculating line shapes for charged-particle analyzers with cylindrical symmetry. Either isotropic or cosine angular distributions of charged-particle emission can be simulated. Application of this technique is demonstrated by simulation of the line shape exhibited by the Helmer planar-retarding-grid analyzer. Ray tracing is used to determine the origin of line-shape asymmetry, new entrance optics are designed, and subsequently, a simulation is used to optimize the dimensions of the analyzer apertures and beam stop to produce a symmetric nearly Gaussian line shape. This result is then verified experimentally. Although the simulation method is applied to a specific problem, it should prove to be of value for the design of any analyzer having axial symmetry.