Abstract: A downhole logging tool comprises an optical sensor to sense a field related to a formation parameter at a first location along the downhole logging tool. A processor receives information from the optical sensor and provides an evaluation of the formation parameter.

Abstract: There is described a method and apparatus for collecting Tomographic inspection data of objects using Compton scatter radiation. The apparatus is of size and weight for portable use within industrial facilities and may be used for assessing integrity of infrastructures in terms of material density, missing materials, thickness of materials, and identification of foreign materials.

Abstract: A radiation dosimeter records absorbed radiation using a passive radiation sensor having one or more radiation-sensitive elements (RSEs) and a radiation-insensitive element (RIE). Floating gate MOSFET technology is used for both the RSEs and the RIE. A reader is connected to the sensor by means of a switching channel in order to pre-charge the sensor before exposure and to read the sensor voltage signals after exposure to radiation. The voltage signals of the RIE are used to correct for the spurious effect of voltage retention loss in the RSEs.

Abstract: A semiconductor sensor system, in particular a bolometer, includes a substrate, an electrode supported by the substrate, an absorber spaced apart from the substrate, a voltage source, and a current source. The electrode can include a mirror, or the system may include a mirror separate from the electrode. Radiation absorption efficiency of the absorber is based on a minimum gap distance between the absorber and mirror. The current source applies a DC current across the absorber structure to produce a signal indicative of radiation absorbed by the absorber structure. The voltage source powers the electrode to produce a modulated electrostatic field acting on the absorber to modulate the minimum gap distance. The electrostatic field includes a DC component to adjust the absorption efficiency, and an AC component that cyclically drives the absorber to negatively interfere with noise in the signal.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: An apparatus for high resolution positron emission tomography (PET) imaging. The apparatus includes at least a first detector and a second detector arranged to detect gamma rays traveling from a target area, the first detector and the second detector being a detector pair. There is at least one collimator for filtering gamma rays reaching the first and second detectors. The collimator defines respective passages filtering gamma rays reaching the respective first and second detectors, the passages being defined to filter for only gamma ray pairs traveling from the target area at a predetermined range of angles with respect to each other, the predetermined range of angles being in the range of 180°-?E, where ?E is less than 1° and greater than 0°.

Abstract: A positron emission tomography (PET) detector assembly is provided. The PET detector assembly includes a plate having a first side and an opposite second side, the plate being fabricated from a thermally conductive material. The PET detector assembly also includes multiple PET detector units coupled to the first side of the plate. The PET detector assembly further includes a readout electronics section coupled to the second side of the plate, wherein, during operation, the readout electronics section generates heat that is transferred to the plate. The plate comprises a heat pipe disposed within the plate and configured to extract the heat from the plate and to transfer the heat away from the plate.

Abstract: A method of inspecting a silicon article includes irradiating a silicon article with infrared radiation, transmitting a portion of the infrared radiation through the silicon article, and filtering the infrared radiation transmitted through the silicon article. Image data is acquired from the filtered infrared radiation and an image of the silicon article reconstructed from the image data. Based on the reconstructed image of the silicon article, one or more anomalies defined within the silicon article are identified.

Abstract: A positron emission tomography (PET) data processing method comprises obtaining PET data from a PET detector, wherein the PET detector comprises an array of detector elements, and wherein the PET data is representative of a PET measurement of at least part of a subject. The method comprises identifying in the PET data a plurality of paired events, wherein each paired event comprises a first photon event in a first region of the PET detector and a second photon event in a second region of the PET detector. The first photon event comprises an energy deposition in a first detector element of the array or in a first detection region of the first detector element due to a scattering of a first photon at a first azimuthal scattering angle and an associated energy deposition by the scattered first photon in a second detector element of the array or in a second detection region of the first detector element or of the second detector element.

Abstract: An infrared sensor assembly for sensing infrared radiation from an object is disclosed. The infrared sensor assembly comprises a sensor array comprising a plurality of sensing elements, provided on or embedded in a substrate extending in a substrate plane. The sensor array comprises at least two infrared sensing elements, each infrared sensing element having a radiation responsive element providing a proportionate electrical signal in response to infrared radiation incident thereto and at least two blind sensing elements, at least one blind sensing element being interspersed among the at least two sensing elements, each blind sensing element being shielded from incident infrared radiation from the object and providing a proportionate electrical signal in response to parasitic thermal fluxes. The output of the sensor array is a function of the infrared sensing elements and of the blind sensing elements such that parasitic thermal fluxes are at least partly compensated for.

Abstract: An infrared detector includes a source region and a drain region which are formed on a semiconductor substrate, an infrared ray absorbing film as a gate insulating film formed on the semiconductor substrate, and a gate electrode which is formed of a transparent electrode for infrared rays on the gate insulating film, in which, when a predetermined voltage is applied to the gate electrode, a predetermined current flows between the source region and the drain region.

Abstract: A radiation sensor includes a radiation source, at least two scintillators having distinguishable scintillation-light-emission-decay characteristics, and shielding configured to provide radiation-paths of different shielding between the source and the at least two scintillators. The shielding is configured such that the scintillators are primarily sensitive to radiation passing through different paths. The signals produced from scintillation events can be sorted by the scintillator that is the source of the event. A source-scintillator-based comparison of the signals may be used to provide information about the material in one or more of the radiation paths. The sensor may be disposed within a borehole to measure the density of the fluid in the borehole.

Abstract: Techniques are described that includes using a memory to store data within a system. The techniques include lowering a supply voltage applied to said memory and ceasing use of the memory to store data within the system. The techniques further include reading values from the memory with the supply voltage being lowered. The techniques further include determining a radiation level from an amount of corrupted ones of the values.

Abstract: An ultra-thin radiation detector includes a radiation detector gas chamber having at least one ultra-thin chamber window and an ultra-thin first substrate contained within the gas chamber. The detector further includes a second substrate generally parallel to and coupled to the first substrate and defining a gas gap between the first substrate and the second substrate. The detector further includes a discharge gas between the substrates and contained within the gas chamber, where the discharge gas is free to circulate within the gas chamber and between the first and second substrates at a given gas pressure. The detector further includes a first electrode coupled to one of the substrates and a second electrode electrically coupled to the first electrode. The detector further includes a first discharge event detector coupled to at least one of the electrodes for detecting a gas discharge counting event in the electrode.

Abstract: The present disclosure relates to a radiation sensor. In one implementation, the sensor may include a radiation detector array having a plurality of pixels; at least two readout connectors having a plurality of contacts, each readout connector being configured for receiving a readout module; a routing circuit having conductors configured for routing electrical signals from each of the plurality of pixels to a corresponding contact of one of the readout connectors. The plurality of pixels is grouped in two or more groups of pixels, at least two pixels of a first group of pixels being separated by at least one pixel from another group of pixels. The routing circuit is configured for leading pixels of the first group of pixels to a first readout connector, and pixels from the other group of pixels to a second readout connector.

Abstract: The use of silicon or vanadium oxide nanocomposite consisting of graphene deposited on top of an existing amorphous silicon or vanadium oxide microbolometer can result in a higher sensitivity IR detector. An IR bolometer type detector consisting of a thermally isolated nano-sized (<one micron feature size) electro-mechanical structure comprised of Si3N4, SiO2 thins films, suspended over a cavity with a copper thin film reflecting surface is described. On top of the suspended thin film is a nanostructure composite comprised of graphene monolayers, covered with various surface densities of VoXy or amorphous nanoparticles, followed by another graphene layer. The two conducting legs are connected to a readout integrated circuit (ROIC) fabricated on a CMOS wafer underneath. The nanostructure is fabricated after the completion of the ROIC process and is integrate able with the CMOS process.

Abstract: A method of calibration-free scanned-wavelength modulation spectroscopy (WMS) absorption sensing is provided by obtaining absorption lineshape measurements of a gas sample on a sensor using 1f-normalized WMS-2f where an injection current to an injection current-tunable diode laser (TDL) is modulated at a frequency f, where a wavelength modulation and an intensity modulation of the TDL are simultaneously generated, extracting using a numerical lock-in program and a low-pass filter appropriate band-width WMS-nf (n=1, 2, . . .

Abstract: A single-shot terahertz imaging system including an interferometer and a terahertz spectrometer. The interferometer includes a beam splitter configured to receive input terahertz radiation and output first terahertz radiation and second terahertz radiation, a sample configured to reflect the first terahertz radiation, and a mirror configured to reflect the second terahertz radiation. The beam splitter is further configured to receive the reflected first terahertz radiation and the reflected second terahertz radiation, and output interfered terahertz radiation. The terahertz spectrometer is configured to measure the interfered terahertz radiation and includes a frequency dispersive element configured to receive the interfered terahertz radiation and output spatially dispersed terahertz radiation, and a terahertz radiation detector configured to determine the intensity of the spatially dispersed terahertz radiation.

Abstract: A system for tracking one or more subjects for collecting airborne contaminants. The system includes one or more subjects configured to collect air contaminants. Each of the one or more subjects includes an identification tag encoded with identification information identifying the each subject. The system further includes an identification reader configured to decode the identification information encoded within the identification tag of a scanned one of the one or more identification tags. A computer receives and stores the decoded identification information in a record in a database. The computer may also receive and stored an identification code for a user who scanned the scanned identification tag in the record in the database. Additional records in the database are created each time the identification tag of one of the one or more subjects is scanned. The one or more subjects are thereby tracked as they collect airborne contaminants and are incubated.

Abstract: A device for detecting radiation particles comprising at least one sensor for sensing radiation particles, capable of supplying an electrical pulse when it is traversed by at least one radiation particle, and at least one detection circuit comprising a voltage-controlled oscillator to which said electrical pulse originating from the sensor is supplied as the control voltage. The voltage-controlled oscillator is a ring oscillator.