Evaluating the Response of Polyvinyl Toluene Scintillators used in Portal Detectors
Abstract
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 . The location and height of the Compton edge had trends, with the greatest height at the center and dropping off on the sides, but the peak location having a maximum in the corner along the axis of the PMT
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2008
- Accession Number
- ADA483290
Entities
People
- Kelly D. Rakes
Organizations
- Air Force Institute of Technology