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