The use of field emission scanning electron microscopes (FESEMs) to analyse submicron-sized defects and particles has become common. These microscopes typically operate at less than 10 kV accelerating voltage and less then 5 nA of beam current. Aside from increasing the imaging resolutions, these microscopes reduce the analysis volume as well as limiting sample charging and contamination.

Prior to the development of the MAXray Parallel Beam Spectrometer, X-ray microanalysis of particles and defects less then 1 µm has been difficult using traditional wavelength dispersive spectrometers (WDS). At low accelerating voltages, there is insufficient overvoltage to excite the K-lines, which have traditionally been used for qualitative and quantitative microanalysis. At low beam currents the intensities of X-rays are very low, resulting in long X-ray counting times or poor peak-to-background ratios.