Beam charge integration in external beam PIXE-PIGE analysis utilizing proton backscattering with an extraction window

In this study, we present a new method for the indirect integration of beam charges in external beam proton-induced X-ray emission and proton-induced γ-ray emission (PIXE–PIGE) analysis. We recorded proton spectra backscattered by a Kapton film extraction window in different sample situations and under different beam currents. We also simulated backscattering spectra using the simulation of backscattering spectra program (SIMNRA). We determined that in a specific geometrical arrangement, different sample situations did not signifi-cantly affect factor CQ (the ratio between integral backscattering proton counts and integral beam charges). We also studied the reproducibility and beam current dependence of factor CQ. The statistic factor of CQ was 28.95 ± 0.6 kilo counts/μC, with a relative standard deviation of 2.0%. Significantly, in external beam PIXE–PIGE analysis, we were able to calculate beam charge integration from the integral backscattering proton counts in an energy region.