Geometrically optimized, Labr3: Ce scintillation sensor array for enhanced stand-off direction finding of gamma radiation sources

A radiation source identification and targeting (RadSITEtrade) innovation has been conceptually demonstrated that remotely detects and identifies one or more localized gamma sources simultaneously and also provides azimuth Directions of each source. The innovation exploits the superior energy resolution of cerium doped lanthanum bromide (LaBr3:Ce) Scintillators to select only photons emanating directly from the localized source(s). Laboratory bench testing provided physical confirmation that an array of unique, elongated geometry, LaBr3:Ce sensors performed as predicted by MCNP modeling to resolve source azimuth direction. The response of each sensor element is anisotropic providing a response dependent on the azimuth of the source relative to the sensor, while the integrated response of the entire array is isotropic, providing a source strength-distance indicator to act as a reference for an original software algorithm that processes each isotope response to determine azimuth. Laboratory tests have confirmed that an array of four (4) sensors would be sufficient to provide plusmn5deg azimuth determination over a 360deg field of view. The approach accommodates a large volume of scintillation material with minimal shielding <20% compared to about 50% for Coded Aperture approaches to provide a high sensitivity and a wide (360deg) field of view. This patent pending innovation has been integrated with an iRobot ATRV robotic platform and autonomous approach to isotopic sources in a field environment has been demonstrated.