Title :
Gamma-ray imaging laboratory measurements using externally segmented germanium detectors
Author :
Callas, J.L. ; Mahoney, W.A. ; Skelton, R.T. ; Varnell, L.S. ; Wheaten, W.A.
Author_Institution :
High Energy Astrophys. Group, Jet Propulsion Lab., Pasadena, CA, USA
fDate :
6/1/1995 12:00:00 AM
Abstract :
Fully two-dimensional gamma-ray imaging with simultaneous high-resolution spectroscopy using an externally segmented germanium sensor has been demonstrated in the laboratory with a calibrated radioactive source. The system employs a single high-purity coaxial detector with its outer electrode segmented into five distinct charge collection regions and a lead coded aperture, with a uniformly redundant array (URA) pattern. A series of one-dimensional responses was collected around 511 keV while the system was rotated in steps through 180°. A nonnegative, linear least-squares algorithm was then employed to reconstruct a two-dimensional image. Corrections for multiple scattering in the detector, and the finite distance of source and detector are made in the reconstruction process
Keywords :
gamma-ray detection; gamma-ray spectroscopy; germanium radiation detectors; 511 keV; calibrated radioactive source; charge collection regions; externally segmented Ge detectors; gamma-ray imaging; high-purity coaxial detector; lead coded aperture; multiple scattering; nonnegative linear least-squares algorithm; outer electrode segmentation; reconstruction; simultaneous high-resolution spectroscopy; uniformly redundant array pattern; Coaxial components; Electrodes; Gamma ray detectors; Germanium; Image reconstruction; Image segmentation; Image sensors; Laboratories; Nuclear imaging; Spectroscopy;
Journal_Title :
Nuclear Science, IEEE Transactions on
