A two dimensional electron analyzer for electron-ion collisions

A toroidal electrostatic analyzer with a two dimensional position sensitive electron detector has been designed and built. The analyzer is installed to the electron spectrometer for measurements of the differential excitation cross sections in electron-ion collisions. The electron position is resolved in the energy and angular dispersive directions of the analyzer by means of microchannel plates and a charge dividing collector. The analyser has an acceptance angle of 90 degrees, and the analysing energy range is 20% of the central pass energy with a relative energy resolution of 1%.