Precision linear and two-dimensional scintillation crystal arrays for x-ray and gamma ray imaging applications

The continuing demand for greater resolution and real-time imaging and the availability of improved, position-sensitive light sensors such as a-Si arrays has pushed the development of small-pixel scintillator arrays. Both linear and two-dimensional arrays of various designs and materials are considered. A discussion of available scintillation materials for small pixel arrays is presented, along with practical decision-making selection guidelines. The trade-offs in design parameters for scintillation arrays are discussed including pixel sizes and reflector types. Examples of pitch and pixel tolerances and transmission of arrays are given. The scintillation performance of several EGO and CsI(TI) arrays on a-Si arrays is shown. References are made to lens-coupled CCD and fiber-optic/PMT readouts. Applications of the arrays discussed include baggage scanning (line scanners), Computed Tomography imaging, Positron Emission Tomography, flash radiography and industrial X-ray inspection.