Monte-Carlo Study on the Characterization of CsI Scintillator for a CsI Based Compton Camera

Compton camera have found many applications in the fields of nuclear medicine, molecular imaging, astrophysics, industrial survey, homeland security and medical physics due to its high sensitivity, high resolution, wide field of view, compactness, low patient dose, multiple radioisotope tracing capability, and inherent 3D imaging capability. Considering the advantages of Compton camera and properties of CsI scintillator, we present a Compton camera which uses this material both as scatterer and absorber. Recently developed pixelated CsI(Tl) consisting of 8 × 8 pixels with the pixel size of 6 × 6 mm² is utilized both as scatterer as well as absorber and radiation detection properties like intrinsic efficiency, good event ratio, and intrinsic sensitivity are presented for gamma ray energy of 0.662 MeV emitted by commonly available Cs¹³⁷ source. Finally a CsI based Compton camera is designed by utilizing 2mm and 20mm thick pixellated CsI modules as scatterer and absorber respectively. An intrinsic sensitivity of 7.6 × 10^-4 was determined for a point source at a distance of 5cm from the scatterer.