MURER, DAVID BLACKIE, DOUGLAS PEERANI, PAOLO 2014 <jats:p> The “FLASH Portals Project” is a collaboration between Arktis Radiation Detectors Ltd (CH), the Atomic Weapons Establishment (UK), and the Joint Research Centre (European Commission), supported by the Technical Support Working Group (TSWG). The program's goal was to develop and demonstrate a technology to detect shielded special nuclear materials (SNM) more efficiently and less ambiguously by exploiting time correlation. This study presents experimental results of a two-sided portal monitor equipped with in total 16 <jats:sup>4</jats:sup> He fast neutron detectors as well as four polyvinyltoluene (PVT) plastic scintillators. All detectors have been synchronized to nanosecond precision, thereby allowing the resolution of time correlations from timescales of tens of microseconds (such as (n, γ) reactions) down to prompt fission correlations directly. Our results demonstrate that such correlations can be detected in a typical radiation portal monitor (RPM) geometry and within operationally acceptable time scales, and that exploiting these signatures significantly improves the performance of the RPM compared to neutron counting. Furthermore, the results show that some time structure remains even in the presence of heavy shielding, thus significantly improving the sensitivity of the detection system to shielded SNM. </jats:p> application/pdf https://sonar.ch/global/documents/283620 eng info:eu-repo/semantics/altIdentifier/doi/10.1142/s201019451460132x info:eu-repo/semantics/altIdentifier/issn/2010-1945 info:eu-repo/semantics/openAccess International Journal of Modern Physics: Conference Series. - World Scientific Pub Co Pte Lt. - 2014, vol. 27, p. 1460132 BENEFITS OF TIME CORRELATION MEASUREMENTS FOR PASSIVE SCREENING http://purl.org/coar/resource_type/c_6501