A novel method for the determination of x-ray mass attenuation coefficients

A new and an accurate method to determine the mass attenuation coefficient, μm, of low energy x-rays employing proportional counter and radioactive source is described. This method incorporates all the recent suggestions of Creagh and Hubbell. A rigid good geometry arrangement, the gating of channels of the spectrometer at FWHM position of the photopeak, the selection of absorber foils, are all done after detailed investigations, in order to minimize the effect of small angle scattering and multiple scattering on the μm value. The method is studied in detail using aluminium as an absorber since it is a standard reference material. The results at each step are presented to demonstrate the credibility of our method. From these results we conclude that the 'best value' for μm can be obtained for those thicknesses which lie in the transmission (T) range 0.5 ≥ T ≥ 0.25. The measured values of μm for copper, silver and for materials such as nylon, teflon, lucite and mylar agree closely with the standard theoretical values indicating the validity of our method. (author)