Electrostatic lens with corrected deceleration ratio variable spherical aberration, wide angle energy analyzer and two-dimensional electron spectrometer

摘要

We propose a compact two-dimensional electron spectrometer capable of variable speed reduction over a wide range and capable of simultaneously measuring two dimensional emission angle distribution measurements with high energy resolution over a wide range of three-dimensional angles.The two-dimensional electron diffraction apparatus comprises an electrostatic lens with a variable reduction ratio variable spherical aberration, a cylindrical mirror type energy analyzer, a wide angle energy analyzer, and a projection lens.An electrostatic lens with a variable deceleration ratio variable spherical aberrationAn axisymmetric aspherical mesh having a concave shape to a point source and an axisymmetric single to multiple electrodesElectrostatic lens for adjusting spherical aberration of charged particles generated from point sourcesIt consists of an axisymmetric reduction electric field generating electrode arranged coaxial with the electrostatic lens.The charged particles generated from the point source converge to the lens outlet by the electrostatic lens.The shape and arrangement of the mesh shape and the electrode are adjusted.A decelerating electric field generating electrode is provided at the first stage of the convergence pointThe reduction ratio of charged particles can be controlled widely by adjusting the applied potential.