A forward scattering technique for the determination of target thickness

Abstract With samples of mass densities in the range 2–10 mg cm 2 and a 2.5 MeV proton beam, effects of particle slowing down and self-absorption on PIXE results become important. For a given energy the proton energy loss in the sample is a function of the sample mass and elemental composition. Three methods for measuring the energy loss distribution after the sample are described and compared, all using a thin foil for scattering and surface-barrier detectors for measuring the proton energies.