Abstract: Systems, methods, and devices for inelastic gamma-ray logging are provided. In one embodiment, such a method includes emitting neutrons into a subterranean formation from a downhole tool to produce inelastic gamma-rays, detecting a portion of the inelastic gamma-rays that scatter back to the downhole tool to obtain an inelastic gamma-ray signal, and determining a property of the subterranean formation based at least in part on the inelastic gamma-ray signal. The inelastic gamma-ray signal may be substantially free of epithermal and thermal neutron capture background.

Abstract: A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

Abstract: A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

Abstract: Systems, methods, and devices for inelastic gamma-ray logging are provided. In one embodiment, such a method includes emitting neutrons into a subterranean formation from a downhole tool to produce inelastic gamma-rays, detecting a portion of the inelastic gamma-rays that scatter back to the downhole tool to obtain an inelastic gamma-ray signal, and determining a property of the subterranean formation based at least in part on the inelastic gamma-ray signal. The inelastic gamma-ray signal may be substantially free of epithermal and thermal neutron capture background.

Abstract: A scintillator type radiation detector package is provided including a scintillation crystal directly coupled to the window of a photomultiplier. A scintillator package is also provided having a longer life at wellbore temperature with minimal deterioration of a hygroscopic scintillation crystal(s). Direct optical coupling of the scintillator to the photomultiplier reduces the amount of light lost at coupling interfaces and improved detection resolution over the conventional structures having separate packages for crystal and photomultiplier.

Abstract: Methods for pre-treating packaging materials of particular composition for use in conjunction with a scintillation crystal are disclosed. The packaging materials may comprise a reflecting material, an elastomer, a reflecting fluorocarbon polymer, a polymer or elastomer loaded with a reflecting inorganic powder (including a reflecting inorganic powder comprising a high reflectance material selected from the group comprising Al2O3, TiO2, BN, MgO, BaSO4 and mixtures thereof), or a highly reflective metal foil selected from the group comprising Ag and Al that is chemically compatible with the scintillator crystal. The scintillator crystal may comprise a crystal selected from the group comprising NaI(Tl), LaBr3:Ce, La—Cl3:Ce, La-halides, and La-mixed halides.

Abstract: The present disclosure provides a protective scintillator package for enclosing a scintillator wherein at least one component in the package is at least partially formed from a viscoelastic material. The protective package may comprise both elastic and viscoelastic materials, which may both be included in one component or may be in differing components. The present disclosure further provides radiation detectors using such scintillator packages, as well as logging tools, and methods for oil exploration.

Abstract: The invention provides a hermetically sealed scintillation crystal package with a window made of a ruggedized material such as ALON (aluminum Oxynitride) or Spinel ceramic (MgAl2O4) where the window is sealed to an external metallic housing part by a brazing or soldering process and the external housing part is welded to the housing containing the scintillation crystal.

Abstract: The present disclosure describes a scintillation crystal having the general formula RE(1?y)MyF3XA3(1?x), wherein RE is selected from the group consisting of La, Gd, Y, Lu, or mixtures thereof; A is selected from Cl, Br or I, and M is an activator ion selected from the group consisting of Ce3+, Pr3+ or Eu3+ and combinations thereof containing two or all three activator ions and further optionally comprising Ho, Er, Tm, or Yb also in the 3+ oxidation state. We also disclose a scintillation detector including a scintillation crystal, and downhole tools and methods of oil exploration utilizing such scintillation crystals.

Abstract: The present invention provides scintillation material having good stability at continuous operating temperatures of at least 175° C. The scintillation material includes a cross linked copolymer with improved aromatic character that form a host plastic having properties of a thermoset polymer. The host plastic contains a primary fluorescent agent and a wavelength shifter. Preferably, the copolymer is comprised of a styrene derivative such as, for example, p-t-butylstyrene, and a higher melting point compound such as, for example, 4-vinylbiphenyl. In accordance with one aspect of the present invention, the scintillation material possesses properties of: good mechanical properties at high temperature (e.g., a Tg of about 180° C.); excellent light output (e.g., energy transfer efficiency); high hydrogen content for fast neutron detection; good optical transparency; and stable operation at temperature.

Abstract: The present invention provides scintillation material having good stability at continuous operating temperatures of at least 175° C. The scintillation material includes a cross linked copolymer with improved aromatic character that form a host plastic having properties of a thermoset polymer. The host plastic contains a primary fluorescent agent and a wavelength shifter. Preferably, the copolymer is comprised of a styrene derivative such as, for example, p-t-butylstyrene, and a higher melting point compound such as, for example, 4-vinylbiphenyl. In accordance with one aspect of the present invention, the scintillation material possesses properties of: good mechanical properties at high temperature (e.g., a Tg of about 180° C.); excellent light output (e.g., energy transfer efficiency); high hydrogen content for fast neutron detection; good optical transparency; and stable operation at temperature.

Abstract: A photosensor comprises a cathode portion (111) sensitive to radiation and/or particles, an anode portion (114) receiving electrons, an evacuated channel (112, 113, 200) having the cathode portion attached to its one end portion in a vacuum-tight manner and the anode portion attached to its other end portion in a vacuum-tight manner, a conductive or semiconductive layer (107) at least partially covering the inner surface of the evacuated channel, wherein the channel is formed of a tubular member (106). A method of manufacturing a channel electron multiplier comprises the steps of forming a tubular member and a conductive or semiconductive layer at least on parts of its inner surface, forming an anode portion and sealing it to the tubular member, evacuating the tubular member, forming a cathode portion sensitive to radiation and/or particles, and sealing the cathode portion to the evacuated tubular member. The detector may at least partially be packed into a casting compound.

Abstract: A plastic scintillator comprises a polymethylpentene thermoplastic material containing a fluorescent additive. This plastic scintillator material functions at high temperatures with excellent optical properties in the detection of neutrons. The plastic scintillator may also include an energy transfer compound, a wavelength shifter, a solubility enhancer for the polymethylpentene and a decolorizing agent.

Abstract: A plastic scintillator comprises a polymethylpentene thermoplastic material containing a fluorescent additive. This plastic scintillator material functions at high temperatures with excellent optical properties in the detection of neutrons.