Effective Atomic Numbers for Some Alloys at 662 keV Using Gamma Rays Backscattering Technique

Abstract

The gamma backscattering is a useful technique in determining effective atomic number of backscattering material. In gamma backscattering technique there is no direct contact with the detector and material under study. So, in the present work the intensity distribution of backscattered photons was determined both as a function of atomic number of the target  and thickness of the target and then find out the effective atomic number of (Pb-Sn, Pb-Zn and Zn-Sn) alloys at 662 keV. These alloys were synthesized in different compositions of Pb, Sn and Zn elements using melt quenching technique with the help of muffle furnace. The intensity distribution of backscattered photons was recorded with the help of GAMMARAD5 (76 mm x 76 mm NaI(Tl) scintillator detector. The experimental results so obtained were compared with the theoretical ones which were computed using atomic to electronic cross-section method with the help of mass attenuation coefficients database of WinXCom. A good agreement has been observed between theoretical and experimental results of the effective atomic numbers for the selected alloys.