BENEFITS OF TIME CORRELATION MEASUREMENTS FOR PASSIVE SCREENING

• Published in: International Journal of Modern Physics: Conference Series
• Main Authors: MURER David, BLACKIE Douglas, PEERANI Paolo
• Language: English
• Published: WORLD SCIENTIFIC PUBL CO PTE LTD 2014
• Subjects: Arktis; Arktis*
• Online Access: https://publications.jrc.ec.europa.eu/repository/handle/JRC95720; http://www.worldscientific.com/doi/abs/10.1142/S201019451460132X; https://doi.org/10.1142/S201019451460132X

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 4He fast neutron detectors as well as four polyvinyltoluene (PVT) plastic scintillators. All detectors have been synchronized to nanosecond precision, therebyallowing the resolution of time correlations from timescales of tens of microseconds (such as (n,alpha) 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. JRC.E.8 - Nuclear security