OPTIMIZATION OF THE SENSITIVITY IN PIXE ANALYSIS

This paper reports on an attempt to investigate how much the sensitivity in PIXE analysis could be improved by optimization of the experimental procedure. The composition and origin of the spectral background in proton excitation of thin plastic foils were studied. It was found that the background could be reduced by good collimation of the beam and efficient shielding of the detector. Minimum detection limits of the order of 0.05–0.2 ppm were obtained. Further improvement with detection limits in the range 0.02–0.03 ppm was achieved by using 5 MeV α-particles for excitation.