A compact Compton camera using scintillators for the investigation of nuclear materials

Abstract

Through its ability to reconstruct high energy (up to several MeV) radiation distributions without using thick mechanical collimation the Compton camera has been used in many studies like astrophysics industrial survey homeland security and medical purposes Whereas the performance of mechanical collimation decreases with radiation energy the Compton camera is effective for detecting higher energy radiation Even though scintillation detectors show high efficiencies high timing resolution and usability without a cooling device the bulky size of conventional photomultiplier tubes limits the scope of their applications to gamma-ray imaging In order to overcome the limitation we constructed a Compton camera which combined sodium doped cesium iodide (CsI(Na)) scintillators with position sensitive photomultiplier tubes (PSPMTs) which had multiple anodes connected to custom made circuits The whole size of each detector is only about 5 cm x 5 cm x 6 cm and therefore it can be carried in hand for investigation of nuclear materials at seaports airports or nuclear power plants The intrinsic imaging efficiency and angular resolution of the compact Compton camera were 1 7293 x 10(-4) and 17 1 for a 356 key source and 4 5254 x 10(-5) and 128 for a 662 key source (C) 2010 Elsevier B V All rights reserved