Simulation results of a dual aperture gamma ray imager

Wonho Lee, David K. Wehe

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)


We report on a hybrid radiation imaging system that combines the advantages of a multi-aperture mechanical collimator with electronic-collimation. The combination offers both efficiency and good angular resolution, and is unique since a single gamma ray can contribute information to both modalities simultaneously. The mechanically collimated camera is most effective for imaging lower energy photons while electronic collimation uncouples spatial resolution from efficiency for higher energies. Our proposed Dual Aperture Gamma Imager (DAGI) combines a high-resolution URA coded aperture with a Compton scatter camera to provide a broader range of energy response suitable for a wider range of industrial applications (50keV-2MeV). The primary detector is a large area LaCl3:Ce scintillator coupled directly to a Hammamatsu PSPMT, chosen to provide portability, efficiency and energy resolution. A pixellated CsI(Na)/PSPMT combination serves as the secondary absorption detector. Point and ring shaped radiation sources (140, 364, 662 and 1275 keV) are simulated. The results show that DAGI can cover a broad energy range of radiation and the combined dual collimation image, using the maximum likelihood method for image reconstruction, yields better images than either a mechanical or electronic image at intermediate energies. The sensitivity loss of the Compton imager due to the introduction of the mechanical collimator is discussed.

Original languageEnglish
Title of host publication2005 IEEE Nuclear Science Symposium Conference Record -Nuclear Science Symposium and Medical Imaging Conference
Number of pages5
Publication statusPublished - 2005
Externally publishedYes
EventNuclear Science Symposium Conference Record, 2005 IEEE - , Puerto Rico
Duration: 2005 Oct 232005 Oct 29

Publication series

NameIEEE Nuclear Science Symposium Conference Record
ISSN (Print)1095-7863


OtherNuclear Science Symposium Conference Record, 2005 IEEE
Country/TerritoryPuerto Rico

ASJC Scopus subject areas

  • Radiation
  • Nuclear and High Energy Physics
  • Radiology Nuclear Medicine and imaging


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