Reference bank of exoelectron dosimeters

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:5264663

Gammage, R B; Cheka, J S

Reference exoelectron dosimeters of BeO ceramic, called Thermalox 995, have been distributed to 37 groups in 17 countries. The apparent sensitivity of the dosimeters at the standard exposure of 20 mR is compared for differeent readers in different laboratories and varies by an order of magnitude. Long-term stability of the exoelectron response is a critical issue if this type of dosimeter is ever to be used routinely. Suggestions are made for the storage, exposure, and reading of detectors in order to examine the stability parameter and compare the experiences of different investigators. One example of reasonably good stability is given for storage in air at 80% relative humidity during a period of one year. Recommendations are made for helping to prevent unnecessary changes in the standardized exoelectron response characteristics. These include annealing the dosimeters at temperatures below 500/sup 0/C, which is the final drying temperature before the detectors leave Oak Ridge, and preventing the condensation of atmospheric moisture onto the BeO at or below the dew-point temperature. Another important recommendation is to avoid exposing the irradiated dosimeters to ultraviolet containing light, otherwise trap transfer effects will produce erroneous results. The reference exoelectron dosimeters serve other useful purposes, such as benchmark dosimeters against which to compare the effectiveness of newer types of exoelectron dosimeters, and as dosimeters for the conduct of basic investigations in different laboratories but on the same material.

• Research Organization: Oak Ridge National Lab., Tenn. (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5264663
• Report Number(s): IAEA-SM-222/46; CONF-771209-5
• Country of Publication: United States
• Language: English

Related Subjects

440102* -- Radiation Instrumentation-- Radiation Dosemeters
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
BERYLLIUM COMPOUNDS
BERYLLIUM OXIDES
CALIBRATION STANDARDS
CHALCOGENIDES
DOSEMETERS
ELECTROMAGNETIC RADIATION
EXOELECTRON DOSEMETERS
HEAT TREATMENTS
HUMIDITY
MEASURING INSTRUMENTS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
READOUT SYSTEMS
SENSITIVITY
STABILITY
STANDARDS
STORAGE
TRAPPING
ULTRAVIOLET RADIATION