An applications guide to vehicle SNM monitors

Abstract

The applications guide introduces its readers to the vehicle special nuclear material (SNM) monitors that are becoming part of safeguards and security measures for nuclear material control at DOE facilities. Building on the foundation provided by an applications guide to pedestrian SNM monitors published in 1986 and a technical report on vehicle monitoring published in 1982, the guide provides an overview of vehicle monitoring in Part 1, a discussion of technical aspects of vehicle monitoring in Part 2, and a catalog of vehicle SNM monitors available to DOE facilities in Part 3. Vehicle monitor upkeep, calibration, testing, and performance are important topics in Part 1. The short technical discussion in Past 2 is devoted to new developments and unique features of vehicle monitors.

Methacrylate-Functionalized 2,5-Diphenyloxazole for Use as Fluorescent Monomers in Plastic Scintillators

“…1 H NMR (500 MHz, DMSO-d 6 ) δ: 8.00 ppm (d, 3 J = 7.73 Hz, 1H), 7.88 ppm (t, 4 J = 1.73 Hz, 1H), 7.85 ppm (dd, 3 J = 7.48 Hz, J 4 = 1.19 Hz, 2H), 7.79 ppm (s, 1H), G: 7.63 ppm (t, 3 J = 8.25 Hz, 1 H), B: 7.51 ppm (t, 3 J = 8.25 Hz, 2H), A: 7.41 ppm (t, 3 J = 7.74 Hz, 1H), 7.36 ppm (dd, 3 J = 8.36 Hz, 4 J = 1.87 Hz, 1H), 6.34 ppm (s, 1H), 5.91 ppm (q, 4 J = 1.26 Hz, 1H), 2.06 ppm (s, 3H). 13 (4). Synthesis of EtMA-PPO followed the procedures for the synthesis of MA-PPO, with 2-(3-(5-phenyloxazol-2-yl)phenoxy)ethan-1-ol (8.1 g, 28.6 mmol, 1 equiv).…”

“…Accurate detection of special nuclear materials (SNMs), such as plutonium and uranium, requires separation of neutron and γ ray signals due to false positives from benign γ emitters such as bananas, porcelain, or kitty litter. , Historically, materials such as 3 He, inorganic crystals, and liquid scintillators were efficient at detecting fast and thermal neutrons, but their high cost and poor ambient stability limit widespread usage . To reduce the usage of these expensive materials, plastic scintillators are of interest as a first line of detection for radioactive materials at airports, international borders, or shipping ports due to their low cost and scalability. − However, most plastic scintillators are sensitive to both neutron and γ rays and thus cannot distinguish between benign and SNMs. Recently, a formulation of plastic scintillator that can distinguish neutron and γ radiation via pulse shape discrimination (PSD) has been developed .…”