A High Sensitivity Gamma Ray Imager (HiSGRI) based on wavelength-shifting fiber readout of LaBr3 scintillators

Brent Budden, Louisiana State University
Michael L. Cherry, IEEE
Gary L. Case, Louisiana State University
Joachim Isbert, Louisiana State University
Michael Stewart, Louisiana State University


Cerium-doped lanthanum bromide offers increased light yield and peak emission at shorter wavelengths compared to standard inorganic scintillators such as NaI or CsI. As a result, lanthanum bromide scintillators can be used as the basis of large scale hard x-ray/gamma ray imaging systems. By coupling a Ce:LaBr3 scintillator with orthogonal layers of wavelength-shifting fibers viewed by multianode photomultiplier tubes to provide x-y position together with an Anger camera array of large area photomultiplier tubes to measure energy, a detector can be constructed with millimeter-scale position resolution and energy resolution only somewhat less than that obtained with bulk scintillators. We present measurements of the light yields and position resolution achievable with such a system. © 2006 IEEE.