This article presents a second-order focusing toroidal spectrometer/detection system for scanning ion/electron microscopes. The spectrometer, combined with a prefocusing electrostatic lens, is predicted to have relative energy resolutions of 0.02% and 0.088% for emission angular spreads of +/- 6 degrees and +/- 10 degrees, respectively, corresponding to transmittances of around 20% and 34%. Initial experimental backscattered electron (BSE) spectra were recorded with a prototype toroidal spectrometer functioning as an attachment unit inside a conventional scanning electron microscope (SEM). These results were used to quantify SEM BSE material contrast.