Efficiency of Scintillator Materials in the Energy Range 8.0-32.0 keV

Technical Report · Mon Jul 01 00:00:00 EDT 2002

DOI:https://doi.org/10.2172/15013576· OSTI ID:15013576

Kinney, J H; Haupt, D L

X-ray microtomography requires the measurement of x-ray attenuation along ray paths through a specimen, and on the inversion of these data to obtain a spatially resolved mapping of the microstructure of the specimen. To do this efficiently, two-dimensional array detectors are often used to measure the transmitted x-rays by capturing and recording each x-ray incident on the detector. The highest resolution CT instruments perform this by converting the incident x-rays to visible light, and then focusing this light onto a charge-coupled-device (CCD) detector. The light output of the scintillator (photons per incident x-ray), the numerical aperture of the optical lens system, and the quantum efficiency of the CCD govern the efficiency of the detection process. Several years earlier, our group performed an investigation aimed at determining the best scintillator material for high-resolution synchrotron CT. The selection criteria included light output in the 8-32 keV energy range, the spatial resolution of the scintillator, the wavelength of the scintillation radiation, and the stability and ease of polishing of the scintillator. A list of the scintillators that we considered, with the exceptions of the more recently developed glass scintillators, is provided in Table 1. Among these scintillators, we concluded that single crystal cadmium tungstate was optimum; we have used this material in all subsequent synchrotron CT systems. Since this original study, several doped-glass scintillators have become available. The LSO (Lu orthosilicates) scintillators, developed for PET scanning, show considerable light output at high energy (energies above 500 keV). Theoretically, the light output of these scintillators should be twice that of the cadmium tungstate. The purpose of this study was to determine the efficiency of two such scintillators (LSO:Yt and IQI-401 high density terbium activated glass) in the energy range from 8-32 keV.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 15013576
• Report Number(s): UCRL-ID-149462; TRN: US0600853
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CADMIUM TUNGSTATES
EFFICIENCY
ENERGY RANGE
GLASS SCINTILLATORS
MONOCRYSTALS
PHOSPHORS
POSITRON COMPUTED TOMOGRAPHY
QUANTUM EFFICIENCY
SPATIAL RESOLUTION
SYNCHROTRONS
TERBIUM