Abstract: An X-ray backscatter imaging system uses frequency modulated X-rays to determine depth of features within a target. An X-ray source generates X-ray radiation modulated by a frequency-modulated bias current. The X-ray radiation impinges upon and is backscattered from multiple depths within the target. A scintillating material receives the backscattered X-rays and generates corresponding photons. A photodetector, having gain modulated by the frequency modulation signal from the local oscillator, receives the photons from the scintillating material and generates an analog output signal containing phase delay information indicative of the distance travelled by the X-rays backscattered from multiple depths within the target. The analog output signal is sampled by an analog-to-digital converter to create a digital output signal. A computer processor performs a discrete Fourier transform on the digital output signal to provide target depth information based on the phase delay information.

Abstract: An X-ray backscatter imaging system uses frequency modulated X-rays to determine depth of features within a target. An X-ray source generates X-ray radiation modulated by a frequency-modulated bias current. The X-ray radiation impinges upon and is backscattered from multiple depths within the target. A scintillating material receives the backscattered X-rays and generates corresponding photons. A photodetector, having gain modulated by the frequency modulation signal from the local oscillator, receives the photons from the scintillating material and generates an analog output signal containing phase delay information indicative of the distance travelled by the X-rays backscattered from multiple depths within the target. The analog output signal is sampled by an analog-to-digital converter to create a digital output signal. A computer processor performs a discrete Fourier transform on the digital output signal to provide target depth information based on the phase delay information.

Abstract: Disclosed herein is a radiation scintillator configured for discrimination of thermal neutrons over gamma radiation and methods for making the same. The scintillator includes a non-scintillating base material and a plurality of spaced-apart micro-particles disposed in the base material. Each micro-particle includes a micro-particle base material, a neutron absorber that emits a neutron reaction product when exposed to thermal neutrons, and a scintillator dopant that emits a scintillation light when exposed to the neutron reaction product.

Abstract: An X-ray backscatter imaging system uses frequency modulated X-rays to determine depth of features within a target. An X-ray source generates X-ray radiation modulated by a frequency-modulated bias current. The X-ray radiation impinges upon and is backscattered from multiple depths within the target. A scintillating material receives the backscattered X-rays and generates corresponding photons. A photodetector, having gain modulated by the frequency modulation signal from the local oscillator, receives the photons from the scintillating material and generates an analog output signal containing phase delay information indicative of the distance travelled by the X-rays backscattered from multiple depths within the target. The analog output signal is sampled by an analog-to-digital converter to create a digital output signal. A computer processor performs a discrete Fourier transform on the digital output signal to provide target depth information based on the phase delay information.

Abstract: An X-ray backscatter imaging system uses frequency modulated X-rays to determine depth of features within a target. An X-ray source generates X-ray radiation modulated by a frequency-modulated bias current. The X-ray radiation impinges upon and is backscattered from multiple depths within the target. A scintillating material receives the backscattered X-rays and generates corresponding photons. A photodetector, having gain modulated by the frequency modulation signal from the local oscillator, receives the photons from the scintillating material and generates an analog output signal containing phase delay information indicative of the distance travelled by the X-rays backscattered from multiple depths within the target. The analog output signal is sampled by an analog-to-digital converter to create a digital output signal. A computer processor performs a discrete Fourier transform on the digital output signal to provide target depth information based on the phase delay information.

Abstract: Systems and methods of x-ray backscatter radiography are provided. A single-sided, non-destructive imaging technique utilizing x-ray radiation to image subsurface features is disclosed, capable of scanning a region using a fan beam aperture and gathering data using rotational motion.

Abstract: A scintillator panel assembly for gamma ray detection includes a scintillator panel having fluorescent material therein for generating a photon when a gamma ray enters the panel, and one or more non-scintillating segments embedded in opposing edges of the scintillator panel which conduct light but do not generate a photon when a gamma ray enters. One or more photon detectors, such as photomultiplier tubes, are disposed immediately adjacent the one or more non-scintillating segments for receiving photons conducted through the non-scintillating segments. The non-scintillating segments preferably have optical transmission and reflection properties that are substantially the same as the optical transmission and reflection properties of the scintillator panel. This configuration provides substantially uniform light output response for all photon generation locations which results in improved spectral resolution.

Abstract: Disclosed is a radiation monitoring system that has a radiation detector for making radiation measurements within a monitored area. An occupancy sensor may be provided for detecting a presence of an entity in the monitored area, and a motion sensor may be provided for detecting a motion of the entity in the monitored area. In a typical embodiment, a radiation measurement collection system is provided which has a first program logic element for collecting the radiation measurements as collected radiation measurements when the presence of the entity is detected and the motion of the entity is detected. Also provided is a method for monitoring an area for intermittent sources of radiation.

Abstract: Systems and methods for scanning an object in an inspection space are disclosed. The systems and methods generally incorporate spatially separated and sequenced Compton x-ray backscatter imaging techniques in a plurality of perspective planes. Such processes as time-gating detectors, weighting scintillation detections, and preferentially accepting signals that originate from a point that is substantially orthogonal to a radiation detector and at least partially shielding out signals that do not originate from a point substantially orthogonal to the detector may be used to enhance the data acquisition process.

Abstract: A scintillator panel assembly for gamma ray detection includes a scintillator panel having fluorescent material therein for generating a photon when a gamma ray enters the panel, and one or more non-scintillating segments embedded in opposing edges of the scintillator panel which conduct light but do not generate a photon when a gamma ray enters. One or more photon detectors, such as photomultiplier tubes, are disposed immediately adjacent the one or more non-scintillating segments for receiving photons conducted through the non-scintillating segments. The non-scintillating segments preferably have optical transmission and reflection properties that are substantially the same as the optical transmission and reflection properties of the scintillator panel. This configuration provides substantially uniform light output response for all photon generation locations which results in improved spectral resolution.

Abstract: Disclosed is a radiation monitoring system that has a radiation detector for making radiation measurements within a monitored area. An occupancy sensor may be provided for detecting a presence of an entity in the monitored area, and a motion sensor may be provided for detecting a motion of the entity in the monitored area. In a typical embodiment, a radiation measurement collection system is provided which has a first program logic element for collecting the radiation measurements as collected radiation measurements when the presence of the entity is detected and the motion of the entity is detected. Also provided is a method for monitoring an area for intermittent sources of radiation.

Abstract: Systems for scanning an object are disclosed. Such systems typically are used to inspect various objects with equipment that produces an image of the object based on penetrating radiation. Examples are X-Ray imaging, infrared imaging, terahertz imaging, and radar imaging. The systems typically include a radiation source and a rotating collimator for generating a beam of energy. A detection array is provided for detecting imagery elements from the beam of energy. A motion controller is provided for instructing a positional driver system to move the radiation source, the rotating collimator and the detector system to the plurality of locations about a support structure. The motion controller may also instruct the positional driver system to turn, oscillate, or otherwise maneuver a portion of the imaging system to the virtually limitless orientations made possible by the disclosed embodiments.

Abstract: A system and method for detection of alpha particles generated by a test material in proximity to a light atomic weight element. The system includes a neutron detector that is configured to detect a rate of generation of neutrons produced by an (alpha, n) reaction between the test material and the light atomic weight element. There is also at least one gamma-ray detector configured to measure a rate of generation of 511 keV gamma rays produced by an annihilation reaction triggered by a positron emission from a daughter product of the light atomic weight element. A comparator is configured to compare the rate of generation of neutrons and the rate of generation of 511 keV gamma rays.

Abstract: Systems and methods for scanning an object in an inspection space are disclosed. The systems and methods generally incorporate spatially separated and sequenced Compton x-ray backscatter imaging techniques in a plurality of perspective planes. Such processes as time-gating detectors, weighting scintillation detections, and preferentially accepting signals that originate from a point that is substantially orthogonal to a radiation detector and at least partially shielding out signals that do not originate from a point substantially orthogonal to the detector may be used to enhance the data acquisition process.

Abstract: Methods and apparatuses for rejecting radioactive interference in a radiation monitoring station. Techniques typically include two radiation detectors positioned to acquire first and second radiation measurements from a moving radiological source in substantially distinct fields of view. A transition zone is established between the fields of view. A function yielding a dependent variable is defined at least in part by the first radiation level measurement and the second radiation level measurement. A detection alert is generated when the dependent variable reaches the first threshold value. In some embodiments a determination is mage as to whether the monitoring station is occupied as a condition for generating a detection alert, and in some embodiments a determination is made as to whether the detected radiological source is likely innocuous or offensive prior to generating a detection alert.

Abstract: A system for interrogating a package, container, vehicle, or similar examination article for the presence of nuclear material. The system typically includes a source of photo-fission energy configured to irradiate the examination article and trigger fission of a fissile or a fissionable material present in the examination article and generate a plurality of fission products, wherein at least one of the plurality of fission products produces a plurality of fission neutrons. A neutron-to-gamma-ray-converter material may be configured to capture up to all of the plurality of fission neutrons and upon capture to emit internal gamma radiation. A gamma radiation detector is typically configured to detect at least a portion of the internal gamma radiation.

Abstract: Methods and an apparatus for reducing the effect of background ionizing radiation depression in vehicle and container monitoring systems due to shielding effects from components of the vehicle or container or modifications thereof. The methods utilize measurements of background radiation in two spectral regions of interest to calculate a normalization constant, and then utilize the normalization constant to normalize measurements in the same regions of interest when a vehicle or container is tested for the presence of a relevant ionizing radiation source such as 137Cs and 76Ga. Subtracting the two measurements to calculate a net difference provides a substantially valid measure of radiation counts in one spectral region of interest. Preferably the regions of interest abut or overlap, and preferably the spectral widths of the regions of interest are selected so that the attenuation of radiation counts due to background shielding effects in the two regions of interest is substantially equal.

Abstract: The invention provides a system for removing or minimizing microphonic noise from a radiation detector signal, such as from a neutron detector, without creating excessive false counts in the electronics that count the radiation events. The system solves the microphonic noise problem using a 3-prong approach: (1) maintaining high dynamic range by avoiding large amplification and the possibility of saturation in the analog stages, (2) sampling the amplified analog signal using a high-resolution analog-to-digital converter (ADC), and (3) implementing a digital filtering algorithm that rejects the noise due to microphonics while passing the signal of interest from the neutron interactions.