Mass Attenuation Studies of Rare Earth Elements at K-Absorption Edge by Attenuation of Compton Scattered Gamma Rays.

Abstract

The mass attenuation coefficient of rare earth elements Eu, Gd, Tb and Er were determined at the K-shell absorption edge by the attenuation of the Compton scattering peak. The gamma rays of energy 59.54 keV from Am²⁴¹ source were scattered by aluminum target to get a broad  span of the Compton scattered peak. After attenuation of Compton peak by absorber was detected using an high resolution intrinsic HPGe detector. A complex histogram obtained was unfolded to best iterative fit by using a Monte Carlo simulation (MCPNX) and Maximum Likelihood Extreme Maximum (ML-EM) method.

The measured experimental values of the mass attenuation coefficient (μ/ρ)_k at  lower and higher K-edge energy were compared with theoretical values shows good agreement reported by   Hubble (1995) NISTIR 5632,  XCOM Table.