29 research outputs found
The use of alpha particle tagged neutrons for the inspection of objects on the sea floor for the presence of explosives
Educational content and challenges encountered when training service user representatives as peer researchers in a mixed study on patient experience of hospital safety
International audienceAbstract Background and objectives In France, following the passing of a 2002 law, service user representatives (SURs) are part of hospital committees in charge of care quality and safety issues. Ten service user representatives (SURs) were recruited and trained as “peer researchers” to participate in all phases of a study aimed at outlining how patients experience hospital safety. This article aims to describe the study protocol and how peer researchers training was designed and implemented to prepare them to drive a qualitative and quantitative research. It also examines the challenges related to collaborative research and how these were resolved. Methods The way our training was conceived belongs to the field of “design-based research”, known for its pragmatic and collaborative scope, in which viewpoints of all participants are included. Our training was therefore based on peer researchers and research sponsors expectations, as well as on recommendations of the literature. Results A 45-h training was held. While the program was meant to train peer researchers to respect scientific norms, it also aimed to improve their sense of self-legitimacy as they navigated their new role. Peer researchers were particularly eager to understand meaning behind the instructions, especially in the field of ethical and scientific norms. Various challenges occurred related to project organization, recruitment and peer researchers involvement. Some issues were overcome by learning how to share control over the research process. Conclusion This experiment highlights the importance of a training program’s duration and quality to prepare SURs for their roles as peer investigators and to create a group dynamic around a research project, even with SURs familiar with patient involvement and our research theme (safety issues). Trainers overcame hurdles by being adaptive and by using educational approaches. They also learned to include trainees’ input, even when it forced them to reconsider their own assumptions
Performances of C-BORD’s tagged neutron inspection system for explosives and illicit drugs detection in cargo containers
International audienceIn the frame of the effective Container inspection at BORDer control points (C-BORD) project [H2020 program of the European Union (EU)], a Rapidly Relocatable Tagged Neutron Inspection System (RRTNIS) has been developed for a non-intrusive inspection of cargo containers, aiming at explosives and other illicit goods detection. Twenty large-volume NaI detectors are used to determine the elements composing inspected materials from their specific gamma-ray spectra signatures induced by fast neutrons. The RRTNIS inspection is focused on a specific suspect area selected by X-ray radiography. An unfolding algorithm decomposes the energy spectrum of this suspect area on a database of pure element gamma signatures. A classification is then performed between inorganic materials, such as metals, ceramics, or chemicals, and organic materials like wood, fabrics, or plastic goods. Concerning organic materials, the obtained elemental proportions of carbon, nitrogen, and oxygen allow discriminating explosives from illicit drugs and benign substances. This article reports on the final laboratory tests performed at Commissariat L'Energie Atomique et aux Energies Alternatives (CEA) Saclay, France, to assess the RRTNIS detection performances before further demonstration tests in a real seaport environment. Simulants of explosives and illicit drugs have been hidden at different depths inside iron or wood cargo materials, which are representative of the different neutron and gamma attenuation properties encountered in real cargo containers. Hundreds of experiments have been performed, showing that a few kilograms of explosives or narcotics can be detected by the RRTNIS in 10-min inspections
Detection of Special Nuclear Materials with tagged neutrons
Conference of 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 ; Conference Code:131365International audienceThe 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