Progress of in-air microbeam system at the Wakasa Wan Energy Research Center

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2011-10, Vol.269 (20), p.2180-2183
• Main Authors: Yasuda, K., Nomachi, M., Sugaya, Y., Yamamoto, H., Komatsu, H.
• Format: Article
• Language: English
• Subjects: Beams (radiation); Emission analysis; Energy (nuclear); External beam; Membranes; Micro-PIGE; Micro-PIXE; Microorganisms; Silicon nitride; Wide area networks; X-rays
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2011.02.026

Modifications of an in-air microbeam system at the Wakasa Wan Energy Research Center designed to improve its performance are described. In the previous setup, a silicon nitride membrane (area: 1×1mm2; thickness: 100nm) was used for the beam exit window and the distance between the window and the sample was restricted to ⩾1.7mm. Due to this restriction, the beam spot size obtained using the previous setup was 13×13μm2. To reduce the beam spot size, the beam exit window was replaced by a silicon nitride membrane (area: 3 (horizontal)×2 (vertical)mm2; thickness: 200nm). In this setup, the sample can be moved as close as 0.7mm to the window, enabling a beam spot size of 7×6μm2 to be achieved. An additional Si-PIN X-ray detector was installed to estimate the relative number of beam particles. It detects X-rays from the beam exit window. The number of the X-rays from the beam exit window (which is proportional to the number of beam particles) is used for quantitative analysis and for online monitoring of the beam current. This system has the potential to be used for simultaneous particle-induced X-ray emission (PIXE) and particle-induced gamma-ray emission (PIGE) measurements and for studying dental medicine.