Determination of X-ray mass attenuation coefficients using HPGe detector

Abstract

A detail analysis of a method to determine the mass attenuation coefficient, ?m, of low energy X-rays employing HPGe X-ray detector and radioactive sources is described. This method incorporates all the suggestions made by Creagh and Hubbell. An optimum distance is set under the broad beam as well as good geometry arrangement. The photon intensity is measured by gating the channel of the spectrometer at FWHM/photo peak. The selection of the absorber foils, optimum counting times are all done after detailed investigations for the ?m value. The method is studied in detail using aluminum/nickel as an absorber since these are standard reference materials. From these results, we conclude that the "best value" for ?m can be obtained for those thicknesses which lie in the transmission (T) range 0.5?T?0.02. The measured values of ?m for Magnesium, Nickel, Copper, Molybdenum and Tantalum and three biological equivalent materials are compared with standard theoretical values. © 2009 Elsevier Ltd. All rights reserved.