Abstract

The determination of particle induced x-ray emission (PIXE) cross sections and the concentration of elements in a material require the knowledge of the target sample thickness. In this aim, measurements of the thickness by three different methods have been performed. These are absorption of X-rays by a ⁵⁵Fe source, transmission of alpha particles by a ²⁴¹Am source and Rutherford backscattering of alpha particles produced by Van de Graff Accelerator with the use of the RUMP simulation code. The results give a thickness with uncertainties ranging from 1 to 8% according to the experimental technique used. The comparison between these methods gives an advantage for the X-rays absorption for its simplicity and accuracy, when backscattering spectrometry is preferred for thin target on backing or as a complementary technique for PIXE analysis.

Key words: Thickness, particle induced x-ray emission (PIXE), Rutherford backscattered (RBS), cross section, rump.