Electron energy spectrometer of retarding field type

An electron energy spectrometer of straight and two-stage retarding field type is presented, where the electric potential on the axis is chosen symmetric as F{cyrillic}(z) ∝ exp (α|z|/L) for -L≤ z≤L (α: positive eigenvalue) in each stage. According to the solution of the trajectory, the spectrometer is so designed as to filter electrons with double focusing. The energy resolution of a compact spectrometer is 2-3 eV in the range of 50-2000 eV and that of a longer one is less than 1 eV. The spectrometers have worked satisfactorily in measuring Auger electrons emitted from ion-atom and electron-atom collisions.