Heat Production Measurement in Rocks using a Gamma Ray Spectrometer with a Solid State Detector

1974 ◽  
Vol 11 (4) ◽  
pp. 526-532 ◽  
Author(s):  
Trevor Lewis
Keyword(s):  
Solid State ◽  
Heat Production ◽  
Gamma Ray ◽  
Average Rate ◽  
Counting Efficiency ◽  
United States Geological Survey ◽  
Solid State Detector ◽  
Gamma Ray Spectrometer ◽  
Absorption Correction ◽  
State Detector

A gamma-ray spectrometer with a solid state detector is described for routine laboratory measurement of U, Th, and K in rocks. The results are used to determine their average rate of heat production. The liquid-nitrogen cooled Ge(Li) detector is used in preference to the conventional NaI detector, even though its counting efficiency is much lower, because its much better resolution permits the isolation of low energy peaks. Using the spectrum obtained over the larger energy range, concentrations can be determined to the same accuracy as with the NaI detector in comparable times. Two analysis techniques were used: the first compares the sample's entire spectrum to those from standards. The alternative technique compares only the sharply resolved peaks measured above the continuum: the counting efficiency is reduced but the sample density can vary as long as a self-absorption correction is made. The results on four United States Geological Survey standard rocks are given.With such a system having a high resolution, the U concentration can be measured using the 63 kev gamma-rays produced in the decay of 234Th to 234Pa, thus indicating whether or not the U series is in equilibrium.

Heat flow and surface radioactivity in the Quirke Lake Syncline near Elliot Lake, Ontario, Canada

1968 ◽  
Vol 5 (6) ◽  
pp. 1417-1428 ◽  
Author(s):  
J. H. Sass ◽  
P. G. Killeen ◽  
E. D. Mustonen
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Gamma Ray ◽  
Average Rate ◽  
Structural Effects ◽  
Gamma Ray Spectrometer ◽  
A Value ◽  
The Mean ◽  
Data Yield ◽  
Ore Zones

Heat flow was measured in seven diamond-drilled holes, ranging in depth from 300 to 900 m, in the Quirke Lake Syncline (82° 30′ W, 46° 30′ N, mean elevation 370 m), Values for individual holes vary from 1.20 to 1.40 with a mean of 1.32 ± 0.02 μcal/cm2s, and no systematic variation was detected within the 50 km2 area studied. Radiometric measurements with a portable, three-channel, gamma-ray spectrometer show a downward concentration (stratigraphically) of Th, U, and K within the lower part of the syncline, with mean concentrations of 12.7 ppm, 3.3 ppm, and 1.9%, respectively. These data yield an average rate of heat production of 4.5 heat generation units (1 hgu = 10−13 cal/cm3s). Taking account of the ore zones, the mean heat production from the syncline is about 6 hgu. Corrections for structural effects and heat production from the ore result in a value of 1.2 for the regional heat flow. This is within the range of other shield values, although somewhat higher than the average for the Canadian Shield. The high value is readily explained if the observed mean surface radioactivity persists to a depth of 7 to 10 km.

Borehole field calibration and measurement of low‐concentration manganese by decay gamma rays

Geophysics ◽  
1986 ◽  
Vol 51 (12) ◽  
pp. 2219-2224 ◽  
Author(s):  
J. L. Mikesell ◽  
F. E. Senftle ◽  
T. A. Lloyd ◽  
A. B. Tanner ◽  
C. T. Merritt ◽  
...  
Keyword(s):  
Solid State ◽  
Scintillation Detector ◽  
Gamma Ray ◽  
Manganese Concentration ◽  
Aluminum Concentration ◽  
Solid State Detector ◽  
Percentage Concentration ◽  
Clay Formation ◽  
State Detector ◽  
Compton Background

The manganese concentration in the Arundel clay formation, Prince Georges County, Maryland, was determined from a borehole by using delayed neutron activation. The neutrons were produced by a [Formula: see text] source. The 847 keV gamma ray of manganese was detected continuously, and its counting rate was measured at intervals of 15 s as the measuring sonde was moved at a rate of 0.5 cm/s. The technique measured the concentration ratio of manganese to aluminum. This ratio, when combined with an estimate of the aluminum concentration of the clay, made it possible to determine the percentage concentration of manganese without using a test‐pit calibration facility. The measurements were made by using an NaI(Tl) scintillation detector and a Ge(HP) solid‐state detector cooled by solid propane. A two‐pass technique had to be used with the scintillation detector because Compton background from the 1 779 keV photopeak of aluminum masked the manganese line. The Compton background did not interfere when the solid‐state detector was used. The borehole measurements compared favorably with a chemical core analysis and were unaffected by water in the borehole.

Tissue equivalent detector data obtained recently on Mir space station. Comparison with Solid State Detector data

1996 ◽  
Vol 18 (12) ◽  
pp. 171-174 ◽  
Author(s):  
J.F Bottollier-Depois ◽  
L Lebaron-Jacobs ◽  
M Siegrist ◽  
E Duvivier ◽  
B Almarcha ◽  
...  
Keyword(s):  
Solid State ◽  
Space Station ◽  
Solid State Detector ◽  
Tissue Equivalent ◽  
State Detector
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