Detection of Special Nuclear Materials with tagged neutrons

B. Pérot (1) , C. Carasco (1) , C. Deyglun (2) , Guillaume Sannié (3) , Jean-François Gameiro (3) , Gwenolé Corre (3) , Karim Boudergui (3) , Vladimir Kondrasovs (3)

1 LMN - Laboratoire de Mesures Nucléaires
2 KEP Nuclear
3 LCAE - Laboratoire Capteurs et Architectures Electroniques

The Associated Particle Technique can be used to detect Special Nuclear Materials in cargo containers. A DT neutron generator, based on the 3H(2H,n)a fusion reaction, produces 14 MeV neutrons which are tagged both in direction and time with an embedded alpha detector. Prompt neutrons and gamma rays emitted during neutron-induced fissions are detected by plastic scintillators, in coincidence with the alpha particle. Nuclear materials are differentiated from non-nuclear materials and crosstalk events using high multiplicity coincidences. The data acquisition electronics is made of compact FPGA boards. Experiments performed with a mock-up of the measurement system are reported and compared to calculations to validate numerical simulation and post-processing tools. Measurements have been performed with different targets made of iron, lead, or uranium, placed in metallic or wood cargo matrixes. The performances of a full scale cargo container inspection system, with a larger number of detectors optimized for container inspection, are also studied by numerical simulation. Random background due to neutrons which are not correlated with an alpha particle, counting statistics, time and energy resolutions of the data acquisition system, are all taken into account to model the measurements as realistically as possible. A wide range of inspections, with the suspicious item in different positions in different cargo matrixes, have been studied.

Keywords: Instrumentation; Nuclear instrumentation; Data acquisition system; MCNP PoliMi; Medical imaging; Neutron-induced fission; Tagged neutron inspection systems; Special Nuclear Materials; associated particle technique; Radioactive materials; Neutron detector; detector; plastic scintillator; Tagged neutron inspection system; Data acquisition; Fusion reactions; Containers; alpha-rays; Associated particle techniques; Cargo container inspection system; Gamma-rays; Inspection; Inspection equipment; Semiconductor detectors; Numerical models; Neutrons; Neutron sources; Data acquisition electronics; Neutron-gamma discrimination; signal processing

Domains: Instrumentation and Detectors [physics.ins-det]; Nuclear Experiment [nucl-ex]; Electronics; Modeling and Simulation; Data Analysis, Statistics and Probability [physics.data-an]

B. Pérot, C. Carasco, C. Deyglun, Guillaume Sannié, Jean-François Gameiro, et al.. Detection of Special Nuclear Materials with tagged neutrons. 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD), Oct 2016, Strasbourg, France. ⟨10.1109/NSSMIC.2016.8069917⟩. ⟨cea-01809225⟩