Proton induced X-ray emission as a tool for trace element analysis

Abstract

For protons and heavier ions with energies in the MeV range we have studied the production of characteristic X-rays from elements with Z≳13 using a semiconductor X-ray spectrometer. Various competing background processes have been identified. Theoretical estimates of the background radiation due to bremsstrahlung from secondary electrons and due to proton bremsstrahlung have been evaluated, and on this basis we have calculated lower limits for the sensitivity obtainable for the concentration of the trace element, ranging down to values of 10 −6−10 −7. Different projectiles and incident energies have been compared, and it is shown that this method of X-ray production is about 3 orders of magnitude cleaner than can be obtained by electron bombardment.