Proton-induced x-ray emission using 68 MeV protons

摘要

The x-ray production cross-sections for the K lines of heavy elements is large enough at 68 MeV proton energy to detect heavy elements via the K in addition to their L x-rays. The large proton penetration range and the fact that the absorption coefficients for the x-ray K lines are much smaller than for the L lines result in an analytical depth of several millimeters. The intensity ratio between the stimulated x-ray L and K lines yields information about the physical composition (e.g. layered structure, layer sequence, hidden structure elements) of the samples supplementary to their chemical composition. Also, based on the now detectable K lines, spectra with mixtures of heavy elements are easier to evaluate, as the K lines will overlap less than the L lines. The experimental set-up and several examples of measurements on archaeological and art historical objects are presented. Copyright (C) 2004 John Wiley Sons, Ltd.