The Department of Homeland Security’s Domestic Nuclear Detection Office (DNDO) continues to work on developing technologies that will bolster our capabilities to detect potential nuclear threats. For the past several years, DNDO has been funding the development of crystal structures called strontium iodide (SrI2) and cesium lithium yttrium chloride (Cs2LiYCl6), or CLYC for short. As of October 2012, these crystals became commercially available for use in radiation detection equipment.
These crystals are critical to the functionality of mobile radiation detectors because of their scintillation properties. A scintillator crystal converts incoming radiation into pulses of light, which are then converted into a measurable electronic signal which indicates the presence and the energy of incident radiation.
This new generation of scintillators will greatly benefit DHS personnel and first responders. Detectors made with CLYC crystals will enable first responders to carry only one compact detector, due to the special density and dual gamma ray/neutron detection quality of CLYC. In addition, the simple crystal structure of CLYC and SrI2 make them relatively easy to grow and less expensive compared to other scintillators; therefore DHS could acquire more mobile radiation units and expand the deployment of radiation detection capabilities. Finally, SrI2 and CLYC crystals provide much better energy resolution than what is currently in use, as the spectra created by these crystals are brighter, have less variation, or both, producing a detector that is faster and more accurate.
Manufacturers of detection equipment are now able to use these two crystal materials to create new and improved devices. This milestone represents not only a technological success, but also a successful transition of DNDO funded research and development efforts into the private sector.