Determination attenuation coefficient and scattering of gamma ray in tissue-equivalent material

Abstract

The photons of gamma rays emitted from radioactive sources (124Am, 137Cs, 226Ra) at energies (60, 662, 186, 242, 295, 352, 609, 1120, 1765) keV respectively have been used to determination attenuation coefficients, mean free path and scattering cross section for two different specimen of organic compound (paraffin wax) and sodium chloride structures were measured by using measurement system of gamma ray Integrated Computer Spectrometer (ICS) has been used and the system is operated by computer according to program prepared for this purpose which is connected with sodium Iodide activated thallium detector (NaI(Tl)) with dimensions (1.5"×1.5"). the specimen was located between the source radioactive and the detector. Accumulation time was 900 seconds. The photo peak, net area and full width at half maximum (FWHM) of photo peak were measured with (USX PCI) software. The results measured and ICRU Report 44 value were compared. The variance between experimental results and human tissue of mass attenuation coefficients for organic compound and sodium chloride combination are lower than 6%.