Lanthanum halide scintillators and optical fiber readout for X-ray/gamma-ray astronomy and national security applications

Michael L. Cherry, Louisiana State University
Gary L. Case, Louisiana State University
Christopher E. Welch, Louisiana State University


The Black Hole Finder Probe (BHFP) mission is intended to survey the local Universe for black holes. One approach to such a survey is a hard X-ray coded aperture imaging telescope operating in the 20 - 600 keV energy band. A sensitive hard X-ray/gamma ray imaging telescope is also well suited to surveillance applications searching for shielded sources of illicit nuclear materials, for example "dirty bomb" materials being smuggled into a harbor or city. The development of new inorganic scintillator materials (e.g., LaBr3 and LaCl3) provides improved energy resolution and timing performance that is well suited to the requirements for these national security and astrophysics applications. LaBr3 or LaCl3 detector arrays coupled with waveshifting fiber optic readout represent a significant advance in the performance capabilities of scintillator-based gamma cameras and provide the potential for a feasible approach to affordable, large area, extremely sensitive detectors. We describe the Coded Aperture Survey Telescope for Energetic Radiation (CASTER), a mission concept for a BHFP, and the High Sensitivity Gamma Ray Imager (HiSGRI), a device intended for surveillance for nuclear materials, and present laboratory test results demonstrating the expected scintillator performance.