Active detection experiments on the 16 MV Hermes-III facility using pulsed bremsstrahlung excitation

We are developing Hermes-III at Sandia National Laboratories as a pulsed bremsstrahlung test-bed for active interrogation for fissionable materials detection. 1 Photons generated by an electron beam striking a Ta converter propagate to a target location 19 m from the electron beam diode, at which various materials are placed. X-rays produce (γ, f) and (γ, n) reactions in fissionable material, while nonfissionable materials such as Pb will result in competing (γ, n) reactions. The intense 30 ns x-ray burst from the diode produces γ-rays and neutrons from materials in the environment, all of which must be discriminated by a successful detector.