Development of a high-current microbeam system

We report on the development of a high-current microbeam system for wavelength-dispersive X-ray micro particle-induced X-ray emission (WDX-μ-PIXE) for chemical state mapping. The microbeam system is composed of two slits and a quadrupole doublet lens mounted on a heavy rigid support. The microbeam system is installed immediately after a switching magnet. A beam brightness of 2.4 pA⋅μm−2⋅mrad−2⋅MeV−1 is obtained at a half-divergence of 0.1 mrad. A beam current of more than 300 pA is obtained for object sizes of 40×10 μm2 with a half-divergence of 0.2 mrad, which corresponds to a beam spot size of 1×1 μm2. The calculated spot size of the beam was 1×1 μm2 and the measured spot size was 1×1.5 μm2. The WDX-μ-PIXE system with the microbeam system is now operational.