The scanning microbeam PIXE analysis facility at NIRS

In March 1999, a HVEE Tandetron was installed in the Electrostatic Accelerator Building of National Institute of Radiological Sciences (NIRS) for particle induced X-ray emission (PIXE) analysis. The specifications of the Tandetron accelerator system operating at NIRS are as follows: the accelerating voltage is 0.4–1.7 MV, and the maximum beam current is 500 nA at 3.4 MeV. The accelerator facility incorporates three beam lines for conventional, in-air and microbeam PIXE analysis. The scanning microbeam PIXE analysis line is based around an Oxford Microbeams OM2000 nuclear microscope end stage. This system provides the ability of multi-elemental mapping over sample areas up to 2 2 mm area with spatial resolutions routinely at 1 1 lm. The scheduled operation of this facility started in April 2000 and is controlled by the Division of Technical Service and Development. The result of beam resolution tests carried out in 2001 are as follows: for scanning transmission ion microscopy, the estimated beam size is 100 200 nm, measured using a 2.6 MeV proton beam scanned over a 12.7 lm repeat distance copper grid. For PIXE operation at 50 pA beam current the estimated best spot size is 0.4 0.6 lm. The microbeam facility is being used for research into the elemental distribution of small biological samples such as biological cells and tissue. 2003 Elsevier B.V. All rights reserved.