Evaluating the Response of Polyvinyl Toluene Scintillators Used in Portal Detectors

<p>Scintillator panels of the same type as those used in portal detector units made of polyvinyl toluene and measuring 12 x 15 x 2 in were purchased from three vendors. Each vendor supplied two scintillators one wrapped by the vendor with aluminum foil coated mylar and two unwrapped. The scintillators where exposed to a ~8 microCurie source collimated 137Cs source which decays with a 662 keV gamma-ray 85% of the time. A Hamamatsu R329-02 photomultiplier tube was optically mated to the 12 x 2 in surface of the scintillator. The pulse-height spectrum was recorded with the source placed at different positions across the surface of the scintillator. Analysis of the pulse-height spectrum determined efficiency and resolution differences across the surface of the scintillation panels. The resolution ranged from 23% at the corner furthest from the PMT to 33% an inch away from the PMT. The absolute efficiency ranged from 0.02 to 0.027 .</p><p>This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact and remains as true to the original work as possible. Therefore you will see the original copyright references library stamps (as most of these works have been housed in our most important libraries around the world) and other notations in the work.</p><p>This work is in the public domain in the United States of America and possibly other nations. Within the United States you may freely copy and distribute this work as no entity (individual or corporate) has a copyright on the body of the work.</p><p>As a reproduction of a historical artifact this work may contain missing or blurred pages poor pictures errant marks etc. Scholars believe and we concur that this work is important enough to be preserved reproduced and made generally available to the public. We appreciate your support of the preservation process and thank you for being an important part of keeping this knowledge alive and relevant.</p>