Ut-battelle, Inc.

Martin Marietta Energy Systems, Inc.

Raytheon Company

The United States of America As Represented by the Department of Energy

Lockheed Martin Energy Research Corporation

John T Mihalczo

Paul A Hausladen

Lynn Allen Boatner

Philip R Bingham

Marc L Simpson

Stephanie A McElhaney

James Allen Mullens

John S Neal

Seth M McConchie

Richard C Lanza

Timothy A Antaya

Michael J Paulus

James T Johnson

Brandon W Blackburn

Bernard Harris

Michael V Hynes

Marion M Chiles

Alan W Hunt

Edward D Blakeman

John E McElroy

Richard Sheffield

Hugh R Andrews

Disclosed herein are representative embodiments of methods, apparatus, and systems for performing combined neutron and gamma ray radiography. For example, one exemplary system comprises: a neutron source; a set of alpha particle detectors configured to detect alpha particles associated with neutrons generated by the neutron source; neutron detectors positioned to detect at least some of the neutrons generated by the neutron source; a gamma ray source; a set of verification gamma ray detectors configured to detect verification gamma rays associated with gamma rays generated by the gamma ray source; a set of gamma ray detectors configured to detect gamma rays generated by the gamma ray source; and an interrogation region located between the neutron source, the gamma ray source, the neutron detectors, and the gamma ray detectors.

Multi-particle inspection using associated particle sources

Disclosed below are representative embodiments of methods, apparatus, and systems for detecting particles, such as radiation or charged particles. One exemplary embodiment disclosed herein is particle detector comprising an optical fiber with a first end and second end opposite the first end. The optical fiber of this embodiment further comprises a doped region at the first end and a non-doped region adjacent to the doped region. The doped region of the optical fiber is configured to scintillate upon interaction with a target particle, thereby generating one or more photons that propagate through the optical fiber and to the second end. Embodiments of the disclosed technology can be used in a variety of applications, including associated particle imaging and cold neutron scattering.

High spatial resolution particle detectors

Disclosed herein are representative embodiments of methods, apparatus, and systems for performing neutron radiography. For example, in one exemplary method, an object is interrogated with a plurality of neutrons. The plurality of neutrons includes a first portion of neutrons generated from a first neutron source and a second portion of neutrons generated from a second neutron source. Further, at least some of the first portion and the second portion are generated during a same time period. In the exemplary method, one or more neutrons from the first portion and one or more neutrons from the second portion are detected, and an image of the object is generated based at least in part on the detected neutrons from the first portion and the detected neutrons from the second portion.

Multiple source associated particle imaging for simultaneous capture of multiple projections

According to one embodiment, a system for interrogating hidden contents of a container comprises a controller, a detector system, and a data system. The controller receives a selection of a source mode of source radiation to generate to interrogate contents of a container. The source mode selection comprises a neutron mode, a gamma ray mode, or a combined neutron-gamma ray mode. The controller instructs a cyclotron to generate the source radiation according to the source mode selection. The detector system detects radiation emitted from the contents in response to the source radiation. The data system analyzes the emitted radiation and describes the contents according to the analysis.

Interrogating hidden contents of a container

A system for detecting fissile and fissionable material originating external to the system includes: aLi loaded glass fiber scintillator for detecting thermal neutrons, x-rays and gamma rays; a fast scintillator for detecting fast neutrons, x-rays and gamma rays, the fast scintillator conjoined with the glass fiber scintillator such that the fast scintillator moderates fast neutrons prior to their detection as thermal neutrons by the glass fiber scintillator; and a coincidence detection system for processing the time distributions of arriving signals from the scintillators.

Fiber optic thermal/fast neutron and gamma ray scintillation detector

A detector system that combines aLi loaded glass fiber scintillation thermal neutron detector with a fast scintillation detector in a single layered structure. Detection of thermal and fast neutrons and ionizing electromagnetic radiation is achieved in the unified detector structure. The fast scintillator replaces the polyethelene moderator layer adjacent theLi loaded glass fiber panel of the neutron detector and acts as the moderator for the glass fibers. Fast neutrons, x-rays and gamma rays are detected in the fast scintillator. Thermal neutrons, x-rays and gamma rays are detected in the glass fiber scintillator.

Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive Li F and the second is a rare-earth activated Y O thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination.

Dual neutron flux/temperature measurement sensor

A digital pulse delay system comprises: a counter incremented responsive to a succession of input pulses and generating a plurality of successive gating signals; a plurality of gates, each having a first input for receiving said input pulses and a second input the receiving a different one of said gating signals; a plurality of pulse delay circuits providing uniform time delays, each receiving an output pulse from a different one of said gates; and, an output circuit combining said uniformly delayed pulses from all of said delay circuits into a single output signal representing a uniformly delayed version of said succession of input pulses. A method for digitally delaying a signal of spaced pulses comprises the steps of: digitally generating a control sequence responsive to said spaced pulses; successively and uniformly digitally delaying successive ones of said spaced pulses in parallel, responsive to said control sequence; and, digitally combining said uniformly delayed pulses into a single output signal representing a uniformly delayed version of said digital signal.

Apparatus and method for digital delays without dead time

Simultaneous measurement of neutron flux and temperature is provided by a single sensor which includes a phosphor mixture having two principal constituents. The first constituent is a neutron sensitive 6LiF and the second is a rare-earth activated Y203 thermophosphor. The mixture is coated on the end of a fiber optic, while the opposite end of the fiber optic is coupled to a light detector. The detected light scintillations are quantified for neutron flux determination, and the decay is measured for temperature determination.

Nuclear reaction detectors capable of position sensitivity with submillimeter resolution in two dimensions are each provided by placing arrays of scintillation or wave length shifting optical fibers formed of a plurality of such optical fibers in a side-by-side relationship in X and Y directions with a layer of nuclear reactive material operatively associated with surface regions of the optical fiber arrays. Each nuclear reaction occurring in the layer of nuclear reactive material produces energetic particles for simultaneously providing a light pulse in a single optical fiber in the X oriented array and in a single optical fiber in the Y oriented array. These pulses of light are transmitted to a signal producing circuit for providing signals indicative of the X-Y coordinates of each nuclear event.

Two-dimensional position sensitive radiation detectors

A scintillation optical fiber system for the on-line monitoring of nuclear reactions in an event-by-event manner is described. In the measurement of tritium production one or more optical fibers are coated with enriched .sup.6 Li and connected to standard scintillation counter circuitry. A neutron generated .sup.6 Li(n )T reaction occurs in the coated surface of .sup.6 Li-coated fiber to produce energetic alpha and triton particles one of which enters the optical fiber and scintillates light through the fiber to the counting circuit. The coated optical fibers can be provided with position sensitivity by placing a mirror at the free end of the fibers or by using pulse counting circuits at both ends of the fibers.

On-line tritium production monitor

A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation even count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

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Oak Ridge, TN, United States of America

John T Mihalczo