Patent ID: 8373122
Filing Date: 2013-02-12
Classification: H01J

Abstract:
1. A charged particle energy analyser comprising irradiation means for irradiating a sample for causing the sample to emit charged particles for energy analysis, an electrode structure having a longitudinal axis, the electrode structure comprising coaxial, inner and outer electrodes having inner and outer electrode surfaces respectively, an entrance opening through which charged particles emitted from said sample can enter a space between said inner and outer electrode surfaces for energy analysis and an exit opening through which charged particles can exit said space, and detection means for detecting charged particles that exit said space through said exit opening, wherein said inner and outer electrode surfaces are defined, at least in part, by spheroidal surfaces having meridonal planes of symmetry orthogonal to said longitudinal axis, said inner and outer electrode surfaces being generated by rotation, about said longitudinal axis, of arcs of two non-concentric circles having different radii, R where R