Experimental results from a second-order focusing toroidal energy spectrometer attachment for scanning electron microscopes

This paper presents experimental results from a second-order focusing toroidal spectrometer attachment for the scanning electron microscope (SEM). The energy resolution of the spectrometer is measured to be 0.38% for an angular spread of ±8°, close to the numerical simulated value of 0.32% based upon direct ray tracing. This result provides experimental confirmation of the superior focusing optics predicted for the spectrometer. Examples of secondary electron (SE) and backscattered electron (BSE) spectra acquired by the attachment are also presented.