15-16 April 2019
University of Surrey
Europe/London timezone

RIID’ing the World of Nuclear Threats: The Next Generation of Radioisotope Identification Detectors

16 Apr 2019, 10:30
15m
University of Surrey

University of Surrey

Guildford, UK

Speaker

Adam Tuff (Kromek Ltd)

Description

Efforts to counter Weapons of Mass Destruction drive the development of highly sensitive state-of-the-art radiation detectors that can rapidly and accurately classify the nature of nuclear threats through identification of radionuclide species with high certainty. The requirements for detectors such as Radio-Isotope Identification Detectors (RIIDs) necessitate a device that can resolve closely-spaced photo peaks in busy spectra, demonstrate high detection efficiency, and include thermal neutron sensitivity to detect the presence of fissile radionuclides that exhibit little or no gamma-ray profile. These devices also need to demonstrate versatility in order to function across a wide range of operations and in harsh environmental conditions.

Kromek has recently developed its own bespoke Application Specific Integrated Circuit (ASIC), “Apollo”, designed to be utilised as a multipurpose processor across many signal processing applications in its nuclear detection products. This ASIC, in addition to technology developed by Kromek for DTRA funded programmes, has allowed the creation of a detection system with a Pulse Shape Discrimination (PSD) capability, which displays stability across a large operational temperature range. The system utilises two novel technologies: A Cs$_2$LiLaBr$_{6-x}$Cl$_x$:Ce (CLLBC) belonging to the Elpasolite scintillator family and an ideal material for this application due to the high gamma-ray energy resolution and thermal neutron sensitivity offered. The CLLBC crystal is also coupled to solid state Silicon Photomultipliers (SiPMs) which allow such a device to meet the low power, low voltage, and small form factor metrics that are difficult to achieve using standard photomultiplier tubes.

We demonstrate how this system performs against what is required of a RIID-type device, including an evaluation of the energy resolution as a function of temperature, and the PSD ability characterised by a figure of merit. We also present the challenges of optimising a system such as this to perform with restrictions of low power requirements, and the potential of these systems to form the core of next generation detectors of compact, dual mode RIIDs.

Primary authors

Adam Tuff (Kromek Ltd) Dr Ed Marsden (Kromek Ltd.)

Co-authors

Mr Craig Duff (Kromek Ltd.) Mr Patrick McGrath (Kromek Ltd.) Mr Ian Radley (Kromek Ltd.)

Presentation Materials