Simulating the Response of Large Plastic Scintillators
N. E. Hertel, Z. Wang,, E. Burgett
Both vehicle and pedestrian portal monitors for the detection of contraband radioactive and special nuclear materials often employ large plastic scintillators. These detection systems result in low-resolution pulse-height spectra. Two 121.9- × 30.48- × 6.35-cm plastic scintillators are available at Georgia Tech. Each scintillator has two identical photomultiplier tubes attached; however, they are attached in different geometrical configurations. The pulse-height distributions for a plastic scintillator of this size have been computed using MCNP5 for various monoenergetic photons over the energy range of interest for portal monitors. The Gaussian energy broadening algorithm available in the code has been used to match the observed resolution of the scintillator to several gamma-ray sources available at Georgia Tech. The computed responses, comparison with experimental responses, and potential for using such an approach to perform crude isotopic identification will be presented and discussed.
This abstract was presented at the 38th Annual Midyear Meeting, "Materials Control and Security: Risk Assessment, Handling, and Detection", Advances in Instrumentation, Materials Detection and Measurement Session, 2/13/2005 - 2/16/2005, held in New Orleans, LA.