Palm-top size X-ray microanalyzer using a pyroelectric focused electron beam with 100-micro-meter diameter

We have developed a palm-top size EPMA (electron probe X-ray microanalyzer), operated by 3 V electric battery except for a rotary vacuum pump. The electron beam was generated by a pyroelectric single crystal, LiTaO₃. A needle was used to make a focused electron beam. The smallest beam size was 100 μm on the sample surface. The X-ray spectra were measured through a Kapton window by a Si-PIN detector for a model specimen containing TiO₂ and MnO₂ particles, which was an aerosol model specimen, where TiO₂ and MnO₂ particles of size about 100-200 μm were separated by a few hundreds micrometers. By moving the sample stage manually, the X-ray spectra were measured for 300 s each by 300 μm e-beam, and the measured X-ray intensities were strong enough for identification of the major element in individual 100-200 μm size aerosol particles.