Experimental determination of energy resolution and transmission characteristics of an electrostatic toroidal spectrometer adapted to a standard scanning electron microscope

The main characteristics of sectorial toroidal energy analyzer for a new electrostatic electron spectrometer adapted to a standard scanning electron microscope are defined and determined experimentally. These transfer characteristics, i.e. intensity-energy response and transmission functions, energy resolution and coupling constant, are needed for spectrometer calibration, registration and energy correction of measured backscattered electron spectra and microtomographic analysis of multilayered structures. The spectrometer response to a monoenergetic primary electron beam and to a continuous energy distribution is discussed. Detector response functions for energy independent and linear energy dependent detectors are considered. For aperture slits of the spectrometer which allow reasonable electron intensities at the detector an energy resolution of about 2.5% is obtained.