GAMMA-RAY IMAGING LABORATORY MEASUREMENTS USING EXTERNALLY SEGMENTED GERMANIUM DETECTORS

Fully two-dimensional gamma-ray imaging with simultaneous high-resolut ion spectroscopy using an externally segmented germanium sensor has be en demonstrated in the laboratory with a calibrated radioactive source . The system employs a single high-purity coaxial detector with its ou ter electrode segmented into five distinct charge collection regions a nd a lead coded aperture with a uniformly redundant array (URA) patter n. A series of one-dimensional responses was collected around 511 keV while the system was rotated in steps through 180 degrees. A nonnegati ve, linear least-squares algorithm was then employed to reconstruct a two-dimensional image. Corrections for multiple scattering in the dete ctor, and the finite distance of source and detector are made in the r econstruction process.