Calculation of coincidence summing corrections for a specific small soil sample geometry

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:392795

Helmer, R G; Gehrke, R J

Previously, a system was developed at the INEL for measuring the {gamma}-ray emitting nuclides in small soil samples for the purpose of environmental monitoring. These samples were counted close to a {approx}20% Ge detector and, therefore, it was necessary to take into account the coincidence summing that occurs for some nuclides. In order to improve the technical basis for the coincidence summing corrections, the authors have carried out a study of the variation in the coincidence summing probability with position within the sample volume. A Monte Carlo electron and photon transport code (CYLTRAN) was used to compute peak and total efficiencies for various photon energies from 30 to 2,000 keV at 30 points throughout the sample volume. The geometry for these calculations included the various components of the detector and source along with the shielding. The associated coincidence summing corrections were computed at these 30 positions in the sample volume and then averaged for the whole source. The influence of the soil and the detector shielding on the efficiencies was investigated.

• 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: 392795
• Report Number(s): INEL--96/00187; CONF-9609258--1; ON: DE96015243
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
C CODES
CORRECTIONS
DATA COVARIANCES
GAMMA RADIATION
GE SEMICONDUCTOR DETECTORS
IDAHO NATIONAL ENGINEERING LABORATORY
MONTE CARLO METHOD
PERFORMANCE
RADIATION MONITORING
SOILS