650 results about "Neutron detection" patented technology

An apparatus for selective radiation detection includes a neutron detector that facilitates detection of neutron emitters, e.g. plutonium, and the like; a gamma ray detector that facilitates detection of gamma ray sources, e.g., uranium, and the like. The apparatus comprises a first light guide, optically coupled to a first optical detector; a second light guide, optically coupled to a second optical detector a sheet of neutron scintillator, opaque for incoming optical photons, said sheet of neutron scintillator sandwiched between the first and the second light guides. The second light guide comprises a gamma ray scintillator material.

Neutron detectors, advanced detector process techniques and advanced compound film designs have greatly increased neutron-detection efficiency. One embodiment of the detectors utilizes a semiconductor wafer with a matrix of spaced cavities filled with one or more types of neutron reactive material such as 10B or 6LiF. The cavities are etched into both the front and back surfaces of the device such that the cavities from one side surround the cavities from the other side. The cavities may be etched via holes or etched slots or trenches. In another embodiment, the cavities are different-sized and the smaller cavities extend into the wafer from the lower surfaces of the larger cavities. In a third embodiment, multiple layers of different neutron-responsive material are formed on one or more sides of the wafer. The new devices operate at room temperature, are compact, rugged, and reliable in design.

A system for scanning aircraft for concealed threats is provided. The system comprises a vehicle and a manipulator arm attached with a scanning head that can be maneuvered in multiple directions to completely scan an aircraft from the outside. The system uses transmission based X-ray detection, backscatter based X-ray detection or a combination thereof, in various embodiments. The system also includes gamma-ray and neutron detectors, for detection of nuclear and radioactive materials.

A neutron detector technology based on 10B thin film conversion of neutrons and detection of neutron capture reaction products in a counter gas within a thin straw tube detector body is described. This neutron detector is based on gas-filled thin wall straw tubes, modified for the conversion of neutrons in a very thin coating, or layer, of 10B, applied for example as a sputter-coated film of 10B4C, that lines the interior, or inside of the straw tube surface; and the subsequent detection of the neutron reaction products in the counter gas. One embodiment of this invention employs a closely-packed array of 10B4C-lined straw tubes employing a very thin and therefore high efficiency 10B4C layer, hence removing the barrier to efficient neutron capture reaction product escape while still providing for efficient neutron capture by providing a plurality of very thin 10B converters, each individual converter element providing efficient reaction product escape. Using such densely packed straw tube detectors of small diameter, a reasonable stack depth allows a high neutron detection efficiency to be achieved on the 1–10Å wavelength range of thermal neutrons. The position of each interacting neutron can be accurately obtained with for example, resistive charge division readout combined with straw decoding electronics to determine the identity of the struck straw.

The present invention provides a gamma-neutron detector based on mixtures of thermal neutron absorbers that produce heavy-particle emission following thermal capture. The detector consists of one or more thin screens embedded in transparent hydrogenous light guides, which also serve as a neutron moderator. The emitted particles interact with the scintillator screen and produce a high light output, which is collected by the light guides into a photomultiplier tube and produces a signal from which the neutrons are counted. Simultaneous gamma-ray detection is provided by replacing the light guide material with a plastic scintillator. The plastic scintillator serves as the gamma-ray detector, moderator and light guide. The neutrons and gamma-ray events are separated employing Pulse-Shape Discrimination (PSD). The detector can be used in several scanning configurations including portal, drive-through, drive-by, handheld and backpack, etc.

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.