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

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.

Download Full-text

Comparison of Stress Measurements by X-Rays with Three Different Detectors and a Strongly Fluorescing Specimen

Advances in X-ray Analysis ◽

10.1154/s0376030800016608 ◽

1978 ◽

Vol 22 ◽

pp. 241-246 ◽

Cited By ~ 2

Author(s):

M. R. James ◽

J. B. Cohen

Keyword(s):

Solid State ◽

Scintillation Detector ◽

Position Sensitive Detector ◽

X Rays ◽

Sensitive Detector ◽

Diffraction Profile ◽

High Background ◽

Solid State Detector ◽

Position Sensitive ◽

State Detector

Measurements on the heat affected zone of a weldment are presented using a gas filled position sensitive detector and a normal diffractometer equipped with a scintillation detector and a solid state detector. The sample, a surface ground titanium alloy, provided a difficult application for the X-ray technique from which a test of the real usefulness of the position sensitive detector could be made. The diffraction profile from the Ti alloy is very broad and the fluorescence produces a high background. The fluorescence is easily rejected using a solid state detector; however, the time of analysis is very long. With the position sensitive detector, the combination of increased energy discrimination over the scintillation detector and the simultaneous measurement of many data points over the broad peak enabled the measurements to be made for the same accuracy in much shorter times than for either the solid state detector or the scintillation detector.

Download Full-text

A two crystal coincidence gamma ray spectrometer using a solid state detector

Nuclear Instruments and Methods ◽

10.1016/0029-554x(64)90153-3 ◽

1964 ◽

Vol 27 (1) ◽

pp. 169-171 ◽

Cited By ~ 2

Author(s):

A.McG. Beech ◽

J.K. Parry ◽

D.F. Urquhart

Keyword(s):

Solid State ◽

Gamma Ray ◽

Solid State Detector ◽

Gamma Ray Spectrometer ◽

State Detector

Download Full-text

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

Canadian Journal of Earth Sciences ◽

10.1139/e74-047 ◽

1974 ◽

Vol 11 (4) ◽

pp. 526-532 ◽

Cited By ~ 14

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.

Download Full-text