Cross section asymmetry of polarized -ray elastic scattering

Omer, M.  ; Shizuma, Toshiyuki*; Koizumi, Mitsuo ; Hajima, Ryoichi*; Hashimoto, Satoshi*; Miyamoto, Shuji*

Nondestructive elemental analysis is highly valued in many fields such as archeology, paleontology, space sciences, nuclear security, and nuclear nonproliferation. These fields usually impose estimating the elemental composition of bulk, large, and inhomogeneous samples nondestructively. Common elemental analysis techniques such as X-ray fluorescence (XRF) may fail in such situations due to self-absorption of low energy X-rays within thin layers of the sample. In the present study, we propose a novel nondestructive method that may be useful in distinguishing the elemental composition of a given sample based on the elastic scattering of linearly polarized and high-energy -rays. Linear polarization of -rays causes asymmetry of the elastic scattering cross sections with respect to the polarization plane of the incident -rays. At specific -ray energies and scattering angles, the asymmetry ratio, R, of the cross sections in two orthogonal planes is characteristic of each element. The measurement of asymmetry ratio of 1.62 MeV linearly polarized -rays at NewSUBARU facility is presented. This work is a contribution of the JAEA to the International Atomic Energy Agency (IAEA) under the agreement of the coordinated research program (CRP), J02015 (Facilitation of Safe and Secure Trade Using Nuclear Detection Technology - Detection of RN and Other Contraband).