microbeam particle-induced X-ray emission spectroscopy electron probe X-ray microanalysis electron probe microanalysis X-ray emission spectroscopy where the X-rays are generated by bombarding a flat polished sample with a finely focused (<10 μm diameter) beam of electrons which results in the ionisation of the inner shells of sample atoms. The decay of the ionised states results in the emission of characteristic X-rays. electron microprobe analysis EMPA CHMO:0000313 electron micro-probe analysis EPXMA FIX:0000674 FIX:0000105 EPMA