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: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

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: 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 radiation detector package includes a support apparatus at least part of which is constructed from a naturally occurring radioactive material. A scintillator is associated with the support apparatus. The support may include a detector housing carrying a photodetector and the scintillator, and the detector housing may be constructed from the naturally occurring radioactive material.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: A radiation generator is provided that includes a target, a cathode to emit electrons in a downstream direction toward the target, a first conductive member downstream of the cathode, and a second conductive member downstream of the cathode. The first and second conductive members have a potential difference with the cathode such that a resultant electric field accelerates the electrons toward the target. A diagnostic current in the second conductive member and a target current in the target may be measured, and an electrical property of the first conductive member may be adjusted based upon the diagnostic current and the target current.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: The present disclosure is intended to overcome the problem of hydrogen contamination of the density signal. The approach is to compute the neutron capture portion of the total gamma ray counts and subtract it from the total counts resulting in a pure inelastic gamma ray measurement.

Abstract: Logging-while-drilling tools incorporating an electronic radiation generator, such as an electronic X-ray generator, and a method for using the same are provided. One example of such a logging-while-drilling tool may include a circumferential drill collar, a chassis disposed radially interior to the drill collar, and an electronic X-ray generator and an X-ray detector disposed within the chassis. The electronic X-ray generator may emit X-rays out of the logging-while-drilling tool into a subterranean formation. The X-ray detector may detect X-rays that return to the logging-while-drilling tool after scattering in the subterranean formation, which may be used to determine a density and/or a lithology of the subterranean formation.

Abstract: A scintillator detector package includes a housing, with a scintillator in the housing. There is a radioactive reflective material between at least a portion of the scintillator and the housing. The radioactive reflective material may be a naturally occurring material, such as Lu2O3, and may be in powdered form. A photodetector may be optically coupled to the scintillator package, and gain stabilization circuitry may perform gain stabilization based upon detecting scintillations of the scintillator caused by radiation emitted by the radioactive reflective material striking the scintillator.

Abstract: Logging-while-drilling tools incorporating an electronic radiation generator, such as an electronic X-ray generator, and a method for using the same are provided. One example of such a logging-while-drilling tool may include a circumferential drill collar, a chassis disposed radially interior to the drill collar, and an electronic X-ray generator and an X-ray detector disposed within the chassis. The electronic X-ray generator may emit X-rays out of the logging-while-drilling tool into a subterranean formation. The X-ray detector may detect X-rays that return to the logging-while-drilling tool after scattering in the subterranean formation, which may be used to determine a density and/or a lithology of the subterranean formation.

Abstract: A neutron generator includes a sealed envelope providing a low pressure environment for a gas. One end of the envelope defines an ion source chamber. A target electrode is disposed at the other end of the envelope. An extracting electrode is spaced apart from the target electrode by an accelerating gap. The extracting electrode bounds the ion source chamber. A dispenser cathode electrode and grid electrode are disposed in the ion source chamber for inducing ionization in the ion source chamber. The dispenser cathode electrode, the grid electrode and the extracting electrode operate at a positive high voltage potential and the target electrode operates at or near ground potential. This configuration provides an electric field gradient that accelerates ions towards the target electrode to induce collisions of ions with target material, thereby causing fusion reactions that generate neutrons. High voltage power supply circuit means supplies a positive high voltage signal to the electrodes of the ion source.

Abstract: A radiation generator may include a generator housing, a target electrode carried by the generator housing, a charged particle source carried by the generator housing to direct charged particles at the target electrode based upon an accelerating potential, and a suppressor electrode carried by the generator housing having an opening therein to permit passage of charged particles to the target electrode. A target extender electrode may be between the suppressor electrode and the target electrode and have an opening therein to permit passage of charged particles to the target. At least one voltage source may be coupled to the target electrode, the suppressor electrode, and the target extender electrode to cause the target electrode to have a voltage greater than a voltage of the suppressor electrode and to cause the target extender electrode to have a voltage greater than the voltage of the suppressor electrode.

Abstract: A radiation generator is provided that includes a target, a cathode to emit electrons in a downstream direction toward the target, a first conductive member downstream of the cathode, and a second conductive member downstream of the cathode. The first and second conductive members have a potential difference with the cathode such that a resultant electric field accelerates the electrons toward the target. A diagnostic current in the second conductive member and a target current in the target may be measured, and an electrical property of the first conductive member may be adjusted based upon the diagnostic current and the target current.

Abstract: A radiation generator includes an insulator, with an ion source carried within the insulator and configured to generate ions and indirectly generate undesirable particles. An extractor electrode is carried within the insulator downstream of the ion source and has a first potential. An intermediate electrode is carried within the insulator downstream of the extractor electrode at a ground potential and is shaped to capture the undesirable conductive particles. In addition, a suppressor electrode is carried within the insulator downstream of the intermediate electrode and has a second potential opposite in sign to the first potential. A target is carried within the insulator downstream of the suppressor electrode. The extractor electrode and the suppressor electrode have a voltage therebetween such that an electric field generated in the insulator accelerates the ions generated by the ion source toward the target.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: Methods and related systems are described for gamma-ray detection. A gamma-ray detector is made depending on its properties and how those properties are affected by the data analysis. Desirable properties for a downhole detector include; high temperature operation, reliable/robust packaging, good resolution, high countrate capability, high density, high Z, low radioactive background, low neutron cross-section, high light output, single decay time, efficiency, linearity, size availability, etc. Since no single detector has the optimum of all these properties, a downhole tool design preferably picks the best combination of these in existing detectors, which will optimize the performance of the measurement in the required environment and live with the remaining non-optimum properties.

Abstract: A radiation generator may include a generator housing, a target electrode carried by the generator housing, a charged particle source carried by the generator housing to direct charged particles at the target electrode based upon an accelerating potential, and a suppressor electrode carried by the generator housing having an opening therein to permit passage of charged particles to the target electrode. A target extender electrode may be between the suppressor electrode and the target electrode and have an opening therein to permit passage of charged particles to the target.

Abstract: A scintillator detector package includes a housing, with a scintillator in the housing. There is a radioactive reflective material between at least a portion of the scintillator and the housing. The radioactive reflective material may be a naturally occurring material, such as Lu2O3, and may be in powdered form. A photodetector may be optically coupled to the scintillator package, and gain stabilization circuitry may perform gain stabilization based upon detecting scintillations of the scintillator caused by radiation emitted by the radioactive reflective material striking the scintillator.