The efficiency calibration and development of environmental correction factors for an in situ high-resolution gamma spectroscopy well logging system
A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. Absolute efficiency calibration of the GSLS was performed using simple cylindrical borehole geometry. The calibration source incorporated naturally occurring radioactive material (NORM) that emitted photons ranging from 186-keV to 2,614-keV. More complex borehole geometries were modeled using commercially available shielding software. A linear relationship was found between increasing source thickness and relative photon fluence rates at the detector. Examination of varying porosity and moisture content showed that as porosity increases, relative photon fluence rates increase linearly for all energies. Attenuation effects due to iron, water, PVC, and concrete cylindrical shields were found to agree with previous studies. Regression analyses produced energy-dependent equations for efficiency corrections applicable to spectral gamma-ray well logs collected under non-standard borehole conditions.
- Research Organization:
- Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC07-94ID13223
- OSTI ID:
- 266704
- Report Number(s):
- INEL-96/0176; ON: DE96013315; TRN: 96:017059
- Resource Relation:
- Other Information: PBD: May 1996
- Country of Publication:
- United States
- Language:
- English
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High resolution gamma spectroscopy well logging system
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