Development of Cs2LiYCl6 scintillator

• Progress in crystal growth of CLYC (2 in. right cylinders).
• 3.6% energy resolution at 662 keV for a 1 in. right cylinder.
• 4.1% energy resolution at 662 keV for a 2 in. right cylinder.
• Gamma ray, thermal and fast neutron detection simultaneously.

Cs2LiYCl6 (CLYC) is one of the most interesting new scintillators developed during the last fifteen years. Its use as a thermal neutron scintillator was discovered in 1999 at the Delft University of Technology in Netherlands. In 2003, CLYC was selected by Radiation Monitoring Devices (RMD) for further studies and ultimately resulted in a commercial product. RMD's investigation of CLYC showed that it is a very good gamma ray detector with excellent 4% or better energy resolution, making it an ideal choice for dual mode detectors. Recently, Bubble Technology Industries of Canada discovered the possibility of fast neutron detection with CLYC, increasing its versatility even further. In this paper, we present the progress of CLYC’s development since its inception, with a focus on the work conducted at RMD. Our initial results with small crystals are presented, followed by data collected with samples of consecutively larger volumes and quality. We discuss the improvements in the energy resolution from 7% to 3.6%, as well as volume from 1 cm3 to 100 cm3. In addition, we address basic properties, gamma ray and neutron detection, pulse shape discrimination, and recently discovered fast neutron detection.