Abstract: A method and system for creating a pulsing scheme. The method may include selecting a pulsing scheme for downhole measurements using a pulsed neutron logging tool and selecting a neutron burst width for the pulsing scheme based at least in part on a neutron tube utilized by the pulsed neutron logging tool during the downhole measurements. The method may further include selecting a carbon-oxygen ratio (CO) neutron burst train for the pulsing scheme to be utilized by the neutron tube, selecting a Sigma decay time for the pulsing scheme, and performing one or more measurements with the pulsed neutron logging tool using the pulsing scheme. The system may include a pulsed neutron logging tool. The pulsed neutron logging tool may include a neutron tube disposed in a pulsed neutron generator, one or more gamma ray scintillator detectors, and one or more thermal neutron detectors.

Abstract: A neutron generator with an ion source within a housing may be used for generating neutrons for neutron logging downhole in a wellbore. The ion source within the housing of the neutron generator may include a hot cathode, an ion source cylinder, a first grid separated from the ion source cylinder, and an extractor separated from the ion source cylinder, the extractor having a second grid.

Abstract: Systems and methods are provided for operating and constructing a neutron generator. In some examples, an ion source within a neutron generator may include a hot cathode; at least one cylindrical sleeve coupled to an exterior surface of the hot cathode; at least one electrode coupled to an interior surface of the neutron generator; and at least one mounting flange, wherein a proximal end of the at least one mounting flange is coupled to the at least one cylindrical sleeve and a distal end of the at least one mounting flange is coupled to the at least one electrode.

Abstract: Systems and techniques are provided for optimizing the performance of a target for a downhole neutron generator. An example method can include disposing a first source material and a first substrate in a vacuum chamber at an initial temperature, evaporating the first source material to be deposited onto a surface of the first substrate, monitoring a temperature of the first substrate during the evaporation of the first source material, and determining a thermal equilibrium process temperature at which the temperature of the first substrate is stabilized. The example method can further include disposing a second source material and a second substrate in the vacuum chamber at the thermal equilibrium process temperature, evaporating the second source material to be deposited onto a surface of the second substrate, and obtaining the second substrate deposited with the second source material for a target of a downhole neutron generator.

Abstract: A method for forming a neutron generating tube. The method may include brazing a welding ring to a neutron generating tube at a first open end, brazing a welding lip to a target rod, and disposing the target rod into the neutron generating tube, wherein the welding lip is at least in part in contact with the welding ring. The method may further include welding the welding lip to the welding ring to form a vacuum envelope, disposing a copper tubing at a second open end of the neutron generating tube opposite the first open end, and pinching off the copper tubing to form a sealed vacuum in the neutron generating tube.

Abstract: A method includes operating a neutron generator in a loading mode by ionizing ionizable gas within an ion source of the neutron generator to create a plurality of ions, and accelerating the plurality of ions by providing a first voltage to a target rod that supports the target to create a first ion beam that bombards a target of the neutron generator. The method also includes operating the neutron generator in a generating mode to generate a plurality of neutrons by accelerating the plurality of ions by providing a second voltage to the target rod to create a second ion beam that bombards the target. The second voltage is greater than the first voltage.

Abstract: A neutron generator with an ion source within a housing may be used for generating neutrons for neutron logging downhole in a wellbore. The ion source within the housing of the neutron generator may include a hot cathode, an ion source cylinder, a first grid separated from the ion source cylinder, and an extractor separated from the ion source cylinder, the extractor having a second grid.

Abstract: A downhole neutron generator includes a housing, a gas reservoir positionable within the housing, a target rod positionable within the housing and having a longitudinal axis aligned with a central axis of the housing, an ion source positionable adjacent to the gas reservoir and between the target rod and the gas reservoir, and a target positionable on a surface of the target rod facing the ion source. The target includes a first metal layer on the surface of the target rod and a second metal layer positionable adjacent to the first metal layer facing the ion source. The second metal layer is a scandium layer.

Abstract: Devices and methods for a rugged semiconductor radiation detector are provided. The semiconductor detector may include a hermetically sealed housing and a semiconductor disposed within the housing that has a first surface and a second surface opposite one another. A first metallization layer may at least partially cover the first surface of the semiconductor and a second metallization layer may at least partially cover the second surface of the semiconductor. The first metallization layer or the second metallization layer, or both, do not extend completely to an edge of the semiconductor, thereby providing a nonconductive buffer zone. This reduces electrical field stresses that occur when a voltage potential is applied between the first metallization layer and the second metallization layer and reduces a likelihood of electrical failure (e.g., due to arcing).

Abstract: Devices and methods for a rugged semiconductor radiation detector are provided. The semiconductor detector may include a hermetically sealed housing and a semiconductor disposed within the housing that has a first surface and a second surface opposite one another. A first metallization layer may at least partially cover the first surface of the semiconductor and a second metallization layer may at least partially cover the second surface of the semiconductor. The first metallization layer or the second metallization layer, or both, do not extend completely to an edge of the semiconductor, thereby providing a nonconductive buffer zone. This reduces electrical field stresses that occur when a voltage potential is applied between the first metallization layer and the second metallization layer and reduces a likelihood of electrical failure (e.g., due to arcing).

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: Devices and methods for a rugged semiconductor radiation detector are provided. The semiconductor detector may include a hermetically sealed housing and a semiconductor disposed within the housing that has a first surface and a second surface opposite one another. A first metallization layer may at least partially cover the first surface of the semiconductor and a second metallization layer may at least partially cover the second surface of the semiconductor. The first metallization layer or the second metallization layer, or both, do not extend completely to an edge of the semiconductor, thereby providing a nonconductive buffer zone. This reduces electrical field stresses that occur when a voltage potential is applied between the first metallization layer and the second metallization layer and reduces a likelihood of electrical failure (e.g., due to arcing).

Abstract: Devices and methods for a rugged semiconductor radiation detector are provided. The semiconductor detector may include a hermetically sealed housing and a semiconductor disposed within the housing that has a first surface and a second surface opposite one another. A first metallization layer may at least partially cover the first surface of the semiconductor and a second metallization layer may at least partially cover the second surface of the semiconductor. The first metallization layer or the second metallization layer, or both, do not extend completely to an edge of the semiconductor, thereby providing a nonconductive buffer zone. This reduces electrical field stresses that occur when a voltage potential is applied between the first metallization layer and the second metallization layer and reduces a likelihood of electrical failure (e.g., due to arcing).

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: Illustrative embodiments of the present invention are directed to devices and methods for ion generation. One such device includes a substrate. The substrate is disposed within a housing that is configured to contain a gas. The substrate includes an interior surface that at least partially defines an interior volume. The substrate also includes a number of channels with walls. Nano-tips are disposed on the walls of the channels.

Abstract: Apparatus and method for detecting radiation-of-interest, such as neutron radiation, employs a gas chamber, a gas that responds to ionizing particles by producing electrons and ions, a cathode that attracts ions, and a supporting layer with a conductive pathway. The conductive pathway collects electrons and responds to electrons that drift towards the conductive pathway by inducing production of further electrons and ions within the gas. The electrons that are collected at the conductive pathway and/or the ions that drift away from the conductive pathway will induce an electrical signal, which can be used to detect the radiation-of-interest.

Abstract: Illustrative embodiments of the present disclosure are directed to devices and methods for X-ray monitoring. Various embodiments of the present disclosure use a target that incorporates a monitor layer. The monitor layer is disposed adjacent to a target layer so that electrons that pass through the target layer enter the monitor layer. As electrons enter the monitor layer, electrical charge is generated within the monitor layer. This electrical charge is measured and used to determine a characteristic of the X-ray generation within the target layer.

Abstract: A combined thermal neutron and epithermal neutron radiation detector includes a plurality of neutron detecting elements arranged such that a first set of the detecting elements is disposed closer to a source of neutron flux scatted from a material or formation to be analyzed than a second set of detecting elements. The neutron detecting elements have a material therein susceptible to capture of thermal neutrons for detection. Signal outputs of the first set of are interconnected and signal outputs of the second set are separately interconnected to provide a signal output corresponding to each of thermal neutron flux and epithermal neutron flux entering the detector.

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.