Design and Construction of External PIXE Beamline of the 1.7 MV Tandem Accelerator for Restoration and Preservation of Cultural Properties

Micro-element analysis based on a PIXE system has a detection limit orders of magnitude lower than can be attainable by X-ray spectrometry techniques using electron excitation such as X-ray fluorescence (detection limit of XRF: ~200 ppm). Under favorable conditions, a detection limit ~1 ppm for thin foils and ~10 ppm for thick samples can be achieved. Therefore, the PIXE analysis system has been successfully applied to solving problems in various fields, including corrosion and oxidation, semi-conductors, metallurgy, thin films, geoscience, air pollution and atmospheric science, biology, medicine, art, archaeology, water analysis, and forensic science. However, since the measurement of characteristic X-rays of the target samples through the conventional PIXE system was carried out under vacuum conditions, the replacement time of target samples was long and the analysis of specific samples such as liquid, powder, and bulky one like cultural properties was difficult, and furthermore, it is possible to damage the target samples by the irradiation heat of particle beam because the cooling system was hard to install in a narrow vacuum chamber. The external PIXE beamline of 1.7 MV tandem accelerator at KOMAC was designed and developed through simulation of beam optics, conceptual design of the beamline, and alignment and construction of total external PIXE beamline. Beam optics of the beamline was carefully simulated and the beamline was well aligned for optimization of beam optics.