Abstract: The use of scintillator compositions having a cubic garnet structure for gamma detection in downhole oil and gas explorations is provided. Specifically, two primary compositions of interest are disclosed, Ca2LnHf2Al3O12 and NaLn2Hf2Al3O12, where Ln is Y, Gd, Tb, or La. Under gamma ray excitation, the electron-hole pairs produced in the garnet lattice structure are trapped by an activator ion to yield an efficient emission in the visible portion of the electromagnetic spectrum. The cubic garnet structure enables the use of these materials as ceramic scintillators with considerable advantages over related single crystals in various ways as disclosed herein, including reduction in cost and improvement in overall performance and durability.

Abstract: A method and an apparatus for detecting photons are disclosed. The apparatus includes a scintillator single crystal and an avalanche photodiode coupled to the scintillator single crystal. The scintillator single crystal is at a temperature greater than about 175° C. and at a shock level in a range from about 20 Grms to about 30 Grms. The scintillator single crystal includes a praseodymium doped composition selected from (LaxY1-x)2Si2O7:Pr, ABCl3-yXy:Pr, A2(Li,Na)LaCl6-yXy:Pr, or any combinations thereof. As used herein A is cesium, rubidium, potassium, sodium, or a combination thereof, B is calcium, barium, strontium, magnesium, cadmium, zinc, or a combination thereof, and X is bromine, iodine, or a combination thereof. Further, (0<x<1), and (0<y<3).

Abstract: A radiation detector useable in a downhole tool configured to be positioned in a borehole includes a printed circuit board and at least one detector element coupled to the printed circuit board. The at least one detector element includes a semiconductor direct conversion material for directly converting gamma rays into electrical signals. The semiconductor direct conversion material includes a cathode surface and an anode surface. In addition, the at least one detector element includes a cathode operatively connected to the cathode surface, and an anode operatively coupled to the anode surface. The radiation detector also includes a voltage source coupled to the printed circuit board and configured to provide a voltage to the at least one detector element.

Abstract: A radiation detector useable in a downhole tool configured to be positioned in a borehole includes a printed circuit board and at least one detector element coupled to the printed circuit board. The at least one detector element includes a semiconductor direct conversion material for directly converting gamma rays into electrical signals. The semiconductor direct conversion material includes a cathode surface and an anode surface. In addition, the at least one detector element includes a cathode operatively connected to the cathode surface, and an anode operatively coupled to the anode surface. The radiation detector also includes a voltage source coupled to the printed circuit board and configured to provide a voltage to the at least one detector element.

Abstract: A detector assembly for use in detecting radiation includes a scintillator and a solid state photomultiplier coupled to the scintillator. The detector assembly may include a light guide connected between the scintillator and the solid state photomultiplier. The detector assembly may be used within a receiver in a logging instrument for use downhole. The receiver is configured to detect radiation produced by an emitter or from naturally occurring sources.

Abstract: A method and an apparatus for detecting photons are disclosed. The apparatus includes a scintillator single crystal and an avalanche photodiode coupled to the scintillator single crystal. The scintillator single crystal is at a temperature greater than about 175° C. and at a shock level in a range from about 20 Grms to about 30 Grms. The scintillator single crystal includes a praseodymium doped composition selected from (LaxY1-x)2Si2O7:Pr, ABCl3-yXy:Pr, A2(Li, Na)LaCl6-yXy:Pr, or any combinations thereof. As used herein A is cesium, rubidium, potassium, sodium, or a combination thereof, B is calcium, barium, strontium, magnesium, cadmium, zinc, or a combination thereof, and X is bromine, iodine, or a combination thereof. Further, (0<x<1), and (0<y<3).

Abstract: A method and an apparatus for detecting photons are disclosed. The apparatus includes a solid state photo multiplier device having a plurality of microcells that have a band gap greater than about 1.7 eV at 25° C. The solid state photo multiplier device further includes an integrated quenching device and a thin film coating associated with each of the microcells. The solid state photo multiplier device disclosed herein operates in a temperature range of about ?40° C. to about 275° C.

Abstract: A logging system for imaging a subterranean formation that includes radiation sources that emit different energy levels of radiation into the formation. The radiation scatters from the formation and is sensed by a single sensor that is responsive to the different energy levels of radiation. The single sensor includes a crystal which includes cesium, lithium, yttrium, cerium, and chlorine. The radiation sources emit neutron rays and gamma rays.

Abstract: A downhole tool with two detectors located at different distances from a neutron source, has at least one dual gamma ray and neutron detector that includes a first detection element made of a neutron detector material, and a second element made of a gamma ray scintillation material, the first detection element and the second detection element being optically connected to a photomultiplier.

Abstract: A neutron porosity measurement device adapted to receive a neutron source configured to emit neutrons having a first energy includes a segmented semiconductor detector located at a predetermined distance from the neutron source. The segmented semiconductor detector includes a plurality of semiconductor neutron detection cells configured to detect neutrons having a second energy smaller than the first energy. The cells are arranged in subsets located between a first distance and a second distance from the neutron source, each subset including semiconductor neutron detection cells surrounding an axis and being disposed in opposite sectors defined relative to the axis at substantially same distance from the neutron source. One or more of the neutron detection cells are configured to acquire data related to detected neutrons independently from one or more other of the neutron detected cells. A method of manufacturing the neutron porosity measurement device is also provided.

Abstract: A neutron porosity measurement device adapted to receive a neutron source configured to emit neutrons having a first energy includes a segmented semiconductor detector located at a predetermined distance from the neutron source. The segmented semiconductor detector includes a plurality of semiconductor neutron detection cells configured to detect neutrons having a second energy smaller than the first energy. The cells are arranged in subsets located between a first distance and a second distance from the neutron source, each subset including semiconductor neutron detection cells surrounding an axis and being disposed in opposite sectors defined relative to the axis at substantially same distance from the neutron source. One or more of the neutron detection cells are configured to acquire data related to detected neutrons independently from one or more other of the neutron detected cells. A method of manufacturing the neutron porosity measurement device is also provided.

Abstract: A neutron porosity measurement device uses semiconductor detectors located at different distances from a cavity configured to accommodate a neutron source. Each of the semiconductor detectors includes (i) a semiconductor substrate doped to form a pn junction, and having microstructures of neutron reactive material formed to extend from a first surface inside the semiconductor substrate, and (ii) electrodes, one of which is in contact with the first surface of the semiconductor substrate and another one of which is in contact with a second surface of the semiconductor substrate, the second surface being opposite to the first surface. The electrodes are configured to acquire an electrical signal occurring when a neutron is captured inside the semiconductor substrate.

Abstract: A neutron porosity measurement device uses semiconductor detectors located at different distances from a cavity configured to accommodate a neutron source. Each of the semiconductor detectors includes (i) a semiconductor substrate doped to form a pn junction, and having microstructures of neutron reactive material formed to extend from a first surface inside the semiconductor substrate, and (ii) electrodes, one of which is in contact with the first surface of the semiconductor substrate and another one of which is in contact with a second surface of the semiconductor substrate, the second surface being opposite to the first surface. The electrodes are configured to acquire an electrical signal occurring when a neutron is captured inside the semiconductor substrate.