43 results about "Neutron pulse" patented technology

A method and associated apparatus for detecting concealed fissile, fissionable or special nuclear material in an article, such as a shipping container, is provided. The article is irradiated with a source of fast neutrons, and fast neutrons released by the fissile or fissionable material, if present, are detected between source neutron pulses. The method uses a neutron detector that can detect and discriminate fast neutrons in the presence of thermal neutrons and gamma radiation. The detector is able to process high count rates and is resistant to radiation damage, and is preferably a solid state neutron detector comprised of silicon carbide.

A scintillator system is provided to detect the presence of fissile material and radioactive material. One or more neutron detectors include scintillator material, and are optically coupled to one or more wavelength shifting fiber optic light guide media that extend from the scintillator material to guide light from the scintillator material to a photosensor. An electrical output of the photosensor is connected to an input of a pre-amp circuit designed to provide an optimum pulse shape for each of neutron pulses and gamma pulses in the detector signals. Scintillator material as neutron detector elements can be spatially distributed with interposed moderator material. Individual neutron detectors can be spatially distributed with interposed moderator material. Detectors and moderators can be arranged in a V-shape or a corrugated configuration.

A multi-stage process utilizing one or more radiation sensors on a distributed network for the detection and identification of radiation, explosives, and special materials within a shipping container. The sensors are configured as nodes on the network. The system supports extended time options at each node and the ability to combine data from multiple nodes for the data acquisition and analysis of shipping containers. The system collects radiation data from one or more nodes and compares the collected data to one or more stored spectral images representing one or more isotopes to identify one or more isotopes present. The identified one or more isotopes present are corresponded to possible materials or goods that they represent. The possible materials or goods are compared with the manifest relating to the container to confirm the identity of materials or goods contained in the container or to detect and / or identify unauthorized materials or goods in the container. The containers are monitored and tracked as they are moved between the nodes. A central monitoring station monitors the radiological sensors, the information from the nodes and the tracking of the shipping containers. For shielded materials, explosives and other types of material detection, a neutron pulse device could be incorporated into the spreader bar position, the secondary position or both.

An apparatus for estimating porosities of a formation includes: a borehole conveyable pulsed neutron generator to emit a pulse of high energy neutrons; a short spaced neutron detector to provide a count rate as a function of time; a long spaced neutron detector to provide a count rate as a function of time; a timing gate to synchronize a timing of neutrons detected by the detectors with respect to the neutron pulse; and a processor. The processor is configured to determine epithermal count rates and thermal count rates for the detectors based on timing of detection of neutrons with respect to the neutron pulse and calculate a first ratio of short to long spaced detector epithermal count rates and a second ratio of short to long spaced detector thermal count rates. The processor estimates an epithermal porosity using the first ratio and a thermal porosity using the second ratio.

A method for detecting the presence of a chemical element in an object by emission of neutrons onto the object, characterized in that the emission of neutrons onto the object is constituted, firstly, by a continuous emission of neutrons originating from an associated particle neutron generator (G1) and, secondly, by an emission of neutron pulses which are superimposed on the continuous emission of neutrons, where the neutron pulses originate from a pulsed neutron generator (G2) which generates neutron pulses of pulse duration T2, where two successive neutron pulses are separated by a duration T4, and where the continuous and pulsed emissions of neutrons on to the object produce a gamma capture radiation and an inelastic gamma radiation.

The present invention relates to a neutron pulse timing mode for pulse neutron whole spectrum saturation logging tool, emitting rapid neutron continuously by broad pulse design, and adding the neutron emitting time corresponding, resolves technique problem that great fluctuation error of Sigma parameter in present neutron pulse timing mode cause Sigma detecting well data can't be used, enhances the gate counting rate of monitoring Sigma and reduces the fluctuation error of Sigma parameter, reaches the similar effect near to result by special Sigma measuring apparatus.