DEVELOPMENT OF A TARGET POSITIONING SYSTEM BASED ON A LASER POSITION SENSOR FOR HIGH-EFFICIENCY WAVELENGTH-DISPERSIVE PIXE ANALYSIS

A precise target positioning system based on a laser position sensor was developed for a high-efficiency wavelength dispersive PIXE analysis. The absolute position and the target surface profile were clearly observed using this position sensor, which was rigidly connected to the target vacuum chamber. By using a thin proton beam (width = 2 mm) and a small target (width = 1 mm), the optimum target position for the measurement of chlorine (Cl) Kβ X-ray could be determined from X-ray detection yields measured at various target positions. We found that the relationship between the X-ray detection yield and the target position can be explained by the target size as well as the incident proton beam width. After precise adjustment of the target position using the above system, target samples with two different Cl compounds, NaCl and NH4Cl, were successfully distinguished from the difference in the measured profiles of Kβ X-ray spectra.