Calibration of a gamma calibration well with an energy-compensated Geiger-Mueller (G-M) tube.
- Gerald L.
- David T.
- Darlene T.
A working-standard Radcal model 1515 radiation monitor with the 1800cc ion chamber was used previously at Los Alamos National Laboratory (LANL) to calibrate and perform routine QA checks on the low-level gamma well, which produces exposure rates in the range of 0.2 mR/h to 10 mR/h. During long integration times (e.g. 24-48 hrs) with the 1800 cc ion chamber, which were required to obtain the necessary precision, changes in temperature and pressure and fluctuations in the zero offset introduced errors that were difficult to account for. An energy compensated G-M tube (SHP-270) was calibrated as a Working Standard to calibrate and perform QA checks on the low-level gamma well. Energy correction factors were determined since the SHP-270 does not have a linear energy response. Monte Carlo N-Particle (MCNP) code was used to determine the exposure rate in 50 keV energy bins as a function of source distance in the well. The results of these calculations were folded into the energy correction factors of the SHP-270 to determine the Corrected Exposure Rate as a function of source distance. To recalibrate the gamma well, the Corrected Exposure Rates were loaded into the source control algorithm, which was then verified to work correctly.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 975324
- Report Number(s):
- LA-UR-01-2606; TRN: US1002429
- Resource Relation:
- Conference: Submitted to: American Radiation Safety Conference and Exposition Health Physics Society's 46th Annual Meeting, June 10-14, 2001, Cleveland, OH
- Country of Publication:
- United States
- Language:
- English
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