A fissile neutron detection system includes an ionizing thermal neutron detector arrangement including an inner peripheral shape that at least substantially surrounds a moderator region for detecting thermal neutrons that exit the moderator region but is at least generally transparent to the incident fissile neutrons. A moderator is disposed within the moderator region having lateral extents such that any given dimension that bisects the lateral extents includes a length that is greater than any thickness of the moderator arrangement transverse to the lateral extents. The moderator can include major widthwise and major lengthwise lateral extents such that any given dimension across the lengthwise and widthwise lateral extents includes a length that is greater than any thickness of the moderator arrangement transverse to the lateral extents.

A slow neutron detection device is disclosed, comprising: a first slow neutron converter and a second slow neutron converter, and a readout electrode wire set and cathode wire sets arranged between the first slow neutron converter and the second slow neutron converter. By arranging a readout circuit between the two slow neutron converters, an electron drift distance is reduced by half without changing a dimension of the detection device, and an average over-threshold probability of a signal is increased.

Boron nitride nanotubes (BNNTs) with 1013 combined with a scintillation gas can serve as the basis for detecting thermal neutrons by detecting light from the decay products of the thermal neutron's absorption on the 10B atoms in the BNNT Material as the resultant decay products pass through the scintillating gas. BNNTs with 11B can be utilized as a scaffold for 238U and combined with a scintillation gas as the basis for detecting fast neutrons via detecting light from the fission decay products passing through the scintillating gas. Both technologies provide high spatial and temporal resolution for the detection of thermal neutrons and fast neutrons respectively.

A narrow thermal neutron detector includes a slidably receivable ionization thermal neutron detector module within an overall housing body. An active sheet layer of the ionization thermal neutron detector module can be tensioned across its width. The ionization thermal neutron detector module can include module upper major surface extents and module lower surface extents such that, when installed within the housing body, the module upper major surface extents are in a first spaced apart confronting relationship with housing upper major surface extents to define a first clearance and module lower major surface extents are in a second spaced apart confronting relationship with housing lower major surface extents to define a second clearance to accommodate housing flexing due to ambient pressure change. The housing body can be formed with a single opening for receiving the ionization thermal neutron detection module or with opposing first and second opposing end openings.

A downhole tool includes a radiation generator configured to output radiation using electrical power received from a power supply. A first portion of the radiation is emitted into a surrounding sub-surface formation. The downhole tool also includes a radiation detector coupled proximate the radiation generator. The radiation detector includes a micromesh gaseous detector, and the radiation detector is configured to output a measurement signal based at least in part on interaction between a second portion of the radiation output by the radiation generator and the radiation detector. Additionally, the downhole tool includes a control system communicatively coupled to the radiation generator and the radiation detector. The control system is configured to determine measured characteristics of the radiation output from the radiation generator based at least in part on the measurement signal and to control operation of the radiation generator based at least in part on the measured characteristics.

A device for measuring the energy of neutrons incident in a first direction is provided. The device comprises a gas between a cathode and an anode, the anode comprising a matrix array of electron detectors, the first direction being orthogonal to the anode-cathode direction.

A water pumping and injecting multi-layered concentric sphere neutron spectrometer includes a neutron detector, a plurality of shells concentrically provided, and a water pumping and injecting device; wherein an innermost shell surrounds a surface of the neutron detector; gaps are formed between adjacent shells for containing liquid; the shells are made of an aluminum material; a valve is arranged on each of the shells except the innermost shell; the water pumping and injecting device is connected to the valve of each of the shells except the innermost shell, so as to input water into the gaps or output the water from the gaps. Compared with conventional neutron spectrometer, weight of the water pumping and injecting multi-layered concentric sphere device and the neutron spectrum detection system of the present invention is greatly reduced, which is conducive to transportation and utilization. Meanwhile, combination of neutron spectrum data measurement and measurement data are increased.

Embodiments of the present disclosure include a system for detecting neutrons with a housing, a gas chamber at least partially defined by the housing, an anode extending through at least a portion of the gas chamber, and a pseudogas arranged within the gas chamber. The pseudogas comprises a mixture of gas and suspended solid particles that contain an element with a high cross-section for thermal neutron capture.

Apparatus for detecting radiation includes a sensor medium disposed within a cavity in a silicon-based substrate. An electrode arrangement is provided for collecting charge generated within the sensor medium by interactions with impinging radiation and drifted through the sensor medium. The electrode arrangement is constituted, in part, by a silicon portion of the substrate that is doped to increase its electrical conductivity and that defines part of the cavity wall.

A narrow thermal neutron detector includes a slidably receivable ionization thermal neutron detector module within an overall housing body. An active sheet layer of the ionization thermal neutron detector module can be tensioned across its width. The ionization thermal neutron detector module can include module upper major surface extents and module lower surface extents such that, when installed within the housing body, the module upper major surface extents are in a first spaced apart confronting relationship with housing upper major surface extents to define a first clearance and module lower major surface extents are in a second spaced apart confronting relationship with housing lower major surface extents to define a second clearance to accommodate housing flexing due to ambient pressure change. The housing body can be formed with a single opening for receiving the ionization thermal neutron detection module or with opposing first and second opposing end openings.