(1) How Does Detection Work?; Current Detection Technol.; (2) Advanced Technol.: Nanocomposite Scintillators; GADRAS: Gamma-Ray Spectrum Analysis Application Using Multiple Algorithms; Computer Modeling to Evaluate Detection Capability; L-3 CAARS: Low-Risk Dual-Energy Radiography System; SAIC CAARS: Higher-Risk, Higher-Benefit Dual-Energy Radiography System; AS&E CAARS: Using Backscattered X-Rays to Detect Dense Material; Muon Tomography; Analyzing a Nuclear Weapon with Nuclear Resonance Fluorescence; Detecting SNM at a Distance; (3) Signatures of Plutonium, Highly Enriched Uranium, and Nuclear Weapons; Detecting Signatures of a Nuclear Weapon or SNM; Evasion of Detection Technol. Illus.