γ - RAY ATTENUATION STUDIES ON NA HALIDES - DETERMINATION OF EFFECTIVE ATOMIC NUMBER & ELECTRON DENSITY FOR MULTI ENERGETIC PHOTONS
A. S. MADHUSUDHAN RAO *
Department of Physics, Geethanjali College of Engineering and Technology, India.
*Author to whom correspondence should be addressed.
The narrow collimated beam transmission method has been employed to take up the γ-ray attenuation studies of γ-photons of different energies on Na halides. The Na halide pellet has been irradiated with γ-rays of four different energies emitted by radioactive sources A NaI(TI) scintillation detector with resolution of 8.5% for 0.662MeV of 137Cs has been used as detector to detect the photons transmitted by the sample. Mass attenuation coefficients (μm) for NaCl, NaBr, NaF and NaI pellets were determined experimentally for each energy. With the help of mixture rule the values of theoretical mass attenuation coefficients of alkali halides have been evaluated. Other remaining photon interaction parameters were calculated using the experimental and theoretical values of mass attenuation coefficients obtained. The experimental values of photon interaction parameters for Na halides are reported for the first time. The experimental values determined are compared with the calculated values and with X-COM values. They are in good agreement.
Keywords: Effective atomic number, atomic cross-section, mean free path