Abstract: A nuclear quadrupole resonance (NQR) sensor assembly includes an active sensor coil configured to transmit radiofrequency (RF) signals to an object of interest and receive return RF signals from the object of interest to generate sensor signals substantially representative of the return signals. The at least one reference coil is configured to receive environmental RF signals to generate reference signals at least partially representative of the environmental RF signals. The at least one reference coil is co-located with the active sensor coil. The active sensor coil and the at least one reference coil are in communication with a correction unit configured to remove interference components from the sensor signals using the reference signals.

Abstract: A contraband detection system is provided. The contraband detection system includes an X-ray system including a front X-ray transmitter/detector and a rear X-ray transmitter/detector. The contraband detection system further includes a quadrupole resonance (QR) system comprising a first QR coil, and a second QR coil, wherein the first and second QR coils are located between the front and rear X-ray transmitter/detectors, and wherein the first and second QR coils are constructed from a material having a low mass attenuation coefficient and a high conductivity such that the first and second QR coils do not substantially interfere with transmitting X-rays and detecting emitted photons using the X-ray system. The contraband detection system further comprise a computing device coupled to the X-ray system and the QR system, the computing device configured to detect contraband based on signals received from the X-ray system and the QR system.

Abstract: A contraband detection system is provided. The contraband detection system includes an X-ray system including a front X-ray transmitter/detector and a rear X-ray transmitter/detector. The contraband detection system further includes a quadrupole resonance (QR) system comprising a first QR coil, and a second QR coil, wherein the first and second QR coils are located between the front and rear X-ray transmitter/detectors, and wherein the first and second QR coils are constructed from a material having a low mass attenuation coefficient and a high conductivity such that the first and second QR coils do not substantially interfere with transmitting X-rays and detecting emitted photons using the X-ray system. The contraband detection system further comprise a computing device coupled to the X-ray system and the QR system, the computing device configured to detect contraband based on signals received from the X-ray system and the QR system.

Abstract: A method for imaging an object is provided. The method includes acquiring tomographic image data of the object at a plurality of frequencies, generating a composite image of the object at each of the plurality of frequencies using the acquired tomographic image data, determining a scaling factor for a first material at each of the plurality of frequencies, determining a scaling factor for a second material at each of the plurality of frequencies, and decomposing the composite images into a first discrete image and a second discrete image using the determined scaling factors, wherein the first discrete image contains any region of the object composed of the first material and the second discrete image contains any region of the object composed of the second material.

Abstract: A nuclear quadrupole resonance (NQR) sensor assembly includes an active sensor coil configured to transmit radiofrequency (RF) signals to an object of interest and receive return RF signals from the object of interest to generate sensor signals substantially representative of the return signals. The at least one reference coil is configured to receive environmental RF signals to generate reference signals at least partially representative of the environmental RF signals. The at least one reference coil is co-located with the active sensor coil. The active sensor coil and the at least one reference coil are in communication with a correction unit configured to remove interference components from the sensor signals using the reference signals.

Abstract: An ion mobility spectrometer including an ion identifying unit, a detector in flow communication with the identifying unit, a gas inlet configured to provide gas carrying a sample of interest, a membrane substantially covering the first opening of the detector inlet, the membrane configured to capture the sample of interest on an exterior surface of the membrane, a heating device coupled to the membrane, the heating device configured to increase a temperature of the membrane to a temperature threshold level once the sample of interest is captured enabling molecules in the captured sample of interest to pass through the membrane and into the detector inlet, and a radiant heat source configured to apply radiant heat to the membrane to increase the temperature of the membrane to the temperature threshold level.

Abstract: A method of operating a screening system includes applying an electromagnetic field to a subject in a region at least partially enclosed by electromagnetic shielding, and measuring an output from a sensor. The output is representative of an interaction of the electromagnetic field and the subject. A trace vapor is collected from the subject within the region, and the trace vapor is identified. Based on the measured sensor output and the identified trace vapor, whether a target material is associated with the subject is determined.

Abstract: A method for detecting contraband is provided. The method includes acquiring tomographic image data of a subject at a plurality of frequencies using low frequency electromagnetic tomography, generating a composite image of the subject at each of the plurality of frequencies using the acquired tomographic image data, determining a differentiation parameter for a tissue material at each of the plurality of frequencies, determining a differentiation parameter for a non-tissue material at each of the plurality of frequencies, decomposing the composite images into a tissue image and a non-tissue image using the determined differentiation parameters, wherein the tissue image contains any region of the subject composed of the tissue material and the non-tissue image contains any region of the subject composed of the non-tissue material, and determining whether the non-tissue image contains any non-tissue material.

Abstract: A method for imaging an object is provided. The method includes acquiring tomographic image data of the object at a plurality of frequencies, generating a composite image of the object at each of the plurality of frequencies using the acquired tomographic image data, determining a scaling factor for a first material at each of the plurality of frequencies, determining a scaling factor for a second material at each of the plurality of frequencies, and decomposing the composite images into a first discrete image and a second discrete image using the determined scaling factors, wherein the first discrete image contains any region of the object composed of the first material and the second discrete image contains any region of the object composed of the second material.

Abstract: A passenger scanning system includes a passenger screening area configured for a person to enter and a shield surrounding at least a portion of the passenger screening area. The shield is configured to reduce a radio frequency interference within the passenger screening area. The passenger scanning system also includes one or more sensors positioned in the passenger screening area at a height configured to be proximate one or more of an abdominal region, a groin region, and a pelvic region of the entered person. The sensors are configured to generate a signal in response to a target substance located in the one or more of the abdominal region, the groin region, and the pelvic region.

Abstract: A method of operating a screening system includes applying an electromagnetic field to a subject in a region at least partially enclosed by electromagnetic shielding, and measuring an output from a sensor. The output is representative of an interaction of the electromagnetic field and the subject. A trace vapor is collected from the subject within the region, and the trace vapor is identified. Based on the measured sensor output and the identified trace vapor, whether a target material is associated with the subject is determined.

Abstract: Apparatus and method for varying field strength in a magnetic resonance system while keeping a relatively uniform magnetic field distribution. In an embodiment, a two-pole, generally u-shaped magnet assembly generates a static and uniform magnetic field. The magnet assembly includes two facing magnet poles separated by an air gap. Holes may be formed with the magnet poles. The field control rods may be placed at a pre-determined distance into these holes and symmetrically or asymmetrically moved across each magnet poles in a controlled manner to change the magnetic field strength while keeping the uniform magnetic field distribution. Maximum magnetic field strength may occur when the rods are removed. Minimum magnetic field strength may occur when the rods are fully inserted.

Abstract: A method for classifying a substance is provided. The method includes transmitting an electromagnetic signal at the substance, measuring a portion of the electromagnetic signal reflected by the substance, determining a reflection coefficient of the substance using the measured portion of the electromagnetic signal, and outputting a classification of the substance based on the determined reflection coefficient.

Abstract: Apparatus and method for varying field strength in a magnetic resonance system while keeping a relatively uniform magnetic field distribution. In an embodiment, a two-pole, generally u-shaped magnet assembly generates a static and uniform magnetic field. The magnet assembly includes two facing magnet poles separated by an air gap. Holes may be formed with the magnet poles. The field control rods may be placed at a pre-determined distance into these holes and symmetrically or asymmetrically moved across each magnet poles in a controlled manner to change the magnetic field strength while keeping the uniform magnetic field distribution. Maximum magnetic field strength may occur when the rods are removed. Minimum magnetic field strength may occur when the rods are fully inserted.

Abstract: A substance identification system is configured to identify at least one detection target faster and with greater accuracy than is possible using prior substance identification systems and/or prior substance identification techniques. A chamber includes a pellet forming area having a predetermined geometry that is configured to maximize a ratio of a pellet surface area to a pellet volume. A magnet is positioned on one side of the chamber and configured to form a pellet of aggregated magnetic particles in the pellet forming area. A laser source is positioned on the same side of the chamber as the magnet and configured to illuminate the pellet, when the pellet is formed in the pellet forming area.