Proactive disclosure
Print version   | | 
Natural Resources Canada > Earth Sciences Sector > Priorities > Strong and safe communities > Radiation Geophysics
Radiation Geophysics Glossary of gamma-ray spectrometry terms
- AGRS
- Airborne Gamma-Ray Spectrometry
- NaI
- Each of the 14 NaI detectors used
in the GSC's Airborne Gamma-Ray Spectrometry system is a single
cylindrical crystal of Sodium Iodide (NaI), having a volume of
approximately 3.5 L.
- Operation Morning Light
- Code name for the 1978 joint Canada-US
operation to locate and recover
debris from the Cosmos 954 nuclear-powered satellite that fell to
earth on January 24, 1978.
- K
- potassium, i.e. K40 (units: %)
- eU
- equivalent uranium concentration by weight (the spectrometer
directly measures Bi214, that is an indirect measure of
uranium) (units: ppm)
- eTh
- equivalent thorium concentration by weight (the spectrometer
directly measures Tl208, that is an indirect measure
of thorium) (units: ppm)
- Total Count
- all counts from 400 to 3000 keV. (units: cps or uR/h)
- Natural Exposure
- computed from K (%), eU (ppm), eTh (ppm) concentrations:
Exposure = 1.505 K + 0.625 eU + 0.31 eTh (uR/h)
(Grasty et al, 1984)
'Exposure' is different from the traditional 'Total Count', in that
it excludes radiation from man-made contaminants.
- Natural Air Absorbed Dose Rate
- computed from K (%), eU (ppm), eTh (ppm) concentrations:
Absorbed Dose Rate = 13.08 K + 5.43 eU + 2.69 eTh (nGy/h)
'Natural Air Absorbed Dose Rate' is different from the traditional
'Total Count', in that it excludes radiation from man-made
contaminants.
- eU/eTh, eU/K, eTh/K
- ratios of K, eU, eTh that are useful for interpretation
- nT
- unit of magnetic total field (nano Tesla)
- ppm
- unit of concentration by weight (part per million), used
for eU (uranium) and eTh (thorium)
- %
-
for potassium (K40): unit of concentration by weight
for VLF: unit of signal strength
- Ur
- unit of radioelement concentration by weight
(1 Ur is defined as the total count rate from 1 ppm uranium in
equilibrium)
- µR/h
- unit of Exposure (micro Roentgen/hour)
- nGy/h
- unit of Natural Air Absorbed Dose Rate (nano Gray/hour)
|
