Application of TW-level pulsed power to the problem of finding fissile material

Development of techniques for finding contraband fissile material is an area of great importance for national and international security.1 Because passive radiation from fissile material is relatively weak and can be readily shielded, “active” techniques have been investigated. Photons and/or neutrons are externally generated and used to induce fissions, the products of which are then measured. The usual approach utilizes relatively low-peak-power linacs. Discussed here is a relatively new technique, called intense pulsed active detection (IPAD).2 With IPAD, high-power generators that deliver TW-level electrical pulses produce intense, short (<; 100-ns) pulses of probing radiation. The short pulse allows access to a variety of fission signatures over relatively short counting times (~ 10 μs to ~ 1 min). The resulting short fission-product measurement time minimizes the signal from natural background.2