Improved energy analyser for the scanning electron microscope

An energy analyser is described for measuring the energy of the secondary electrons in the scanning electron microscope. It consists of a 63°deflection cylindrical analyser followed by an electron collimator. This is simpler than a mirror design reported previously and gives a higher transmission factor and less defocusing of the electron beam of the microscope. This analyser has been applied to measure point-to-point variations in surface potential with an accuracy to ±1 V.