186 results about "X ray photons" patented technology

The invention provides methods and apparatus for detecting radiation including x-ray photon (including gamma ray photon) and particle radiation for radiographic imaging (including conventional CT and radiation therapy portal and CT), nuclear medicine, material composition analysis, container inspection, mine detection, remediation, high energy physics, and astronomy. This invention provides novel face-on, edge-on, edge-on sub-aperture resolution (SAR), and face-on SAR scintillator detectors, designs and systems for enhanced slit and slot scan radiographic imaging suitable for medical, industrial, Homeland Security, and scientific applications. Some of these detector designs are readily extended for use as area detectors, including cross-coupled arrays, gas detectors, and Compton gamma cameras. Energy integration, photon counting, and limited energy resolution readout capabilities are described. Continuous slit and slot designs as well as sub-slit and sub-slot geometries are described, permitting the use of modular detectors.

A method of determining the doses of neutrons, gamma and X-ray photons, beta, alpha and other ionizing radiations using a method of image processing in spatial and frequency domain that produces parameters that are related to the radiation dose absorbed in a luminescent material. Portions of the luminescent material may be covered by different converters to allow for doses of different radiations to be discriminated.

A method for single photon counting transmission computed tomography (CT) is described. The method is based on an apparatus consisting of a radiation source and detectors on an opposite side of the subject from the source. The radiation source is for example an X-ray tube. The detectors are independently connected to parallel, fast, low-noise processing electronics capable of recording and counting individual X-ray photons at very high rate. In one embodiment of the invention, said detector is made of a scintillator coupled to a photodetector. The photodetector can be an avalanche photodiode (APD). The method comprises the steps of: directing the low energy radiation source toward the subject; detecting the radiation transmitted through the subject towards the detectors and recording the position and energy of each individual X-ray photon; rotating the radiation source and detectors around the subject; recording data for each position of the radiation source and detectors around the subject to form projections; and creating a CT image from the recorded projection data. The proposed method allows enhancing CT image contrast and reducing radiation dose to the patient by counting individual X-ray photons.

An apparatus for X-ray scanning of vehicles includes a pulsed X-ray source generating X-rays. A collimator forms a fan-shaped beam from the X-rays. A detector detects the fan-shaped beam after it passes through a vehicle. A speed sensor measures a speed of the vehicle passing through the apparatus and providing an electrical output corresponding to the speed. An image formation module converts an output of the detector into an image of the vehicle, based on the measured speed of the vehicle. A cross-section of the fan-shaped beam is substantially similar to a width of the detector. The X-rays comprise primarily photons with energy between 2.5 and 9 MeV. A filter is adjacent to the collimator for filtering out low energy X-ray photons. A vehicle presence sensor can be used, whose output is used to turn the X-ray source on and off. An alignment platform can be used for aligning the fan-shaped beam with the detector. A frequency of the pulses is adjusted based on the speed of the vehicle. The X-ray source is turned off if the speed of the vehicle is below a predetermined threshold.

An image forming apparatus of the present invention includes a movable body to be charged and a charger including a charging member that contacts or adjoins the body to be charged and applies a voltage, including an AC component, to the charging member for thereby charging the body. A protection substance for protecting the surface of the body from deterioration ascribable to charging is caused to exist on the body. The number of particular elements, contained in the protection substance and detected by an X-ray photon spectral analyzer (XPS) in a zone where the charging member charges the body, is held in a particular ratio to the total number of all elements constituting the outermost surface of the body and also detected by the XPS.

A pixel for the detection of electromagnetic radiation or high energy particles or charge packets, in particular for detecting X-ray photons, comprises a radiation receptor for converting the radiation into a sensing signal, the pixel being adapted for performing both pulse detection and integration of the same sensing signal.

A pixel for the detection of electromagnetic radiation or impinging high energy particles, in particular for detecting X-ray photons, comprises a radiation receptor for converting the electromagnetic radiation or impinging high energy particles into a radiation signal, a converter for converting the radiation signal into a pulse train, and an analog accumulator for accumulating the pulses of a pulse train to an analog signal for readout. The analog accumulator is adapted such that the analog signal is non-linearly proportional to the pulse count. Such non-linear analog accumulator has the advantage of an large dynamic range.

The present invention relates to an apparatus (10) for counting X-ray photons (12, 14). The apparatus (10) comprises a sensor (16) adapted to convert a photon (12, 14) into a charge pulse, a processing element (18) adapted to convert the charge pulse (51) into an electrical pulse (53) and a first discriminator (20) adapted to compare the electrical pulse (53) against a first threshold (TH1) and to output an event (55) if the first threshold (TH1) is exceeded. A first counter (22) counts these events (55), unless counting is inhibited by a first gating element (24). The first gating element (24) is activated when the first discriminator (20) outputs the event (55), and it is deactivated, when the processing of a photon (12, 14) is found to be complete or about to be completed by a measurement or by the knowledge about the time that it takes to process a photon (12, 14) in the processing element (18). By activating and deactivating the first counter (22) pile-up events, i.e. pile-up of multiple electrical pulses (53), can be addressed. The invention also relates to a corresponding imaging device and a corresponding method.

The invention provides a pulsar navigation method with a single detector, which comprises the steps that an X-ray detector on a spacecraft receives X-ray photons from four millisecond pulsars one by one and measures times when the X-ray photons arrive at the X-ray detector; the arrival times are saved as original observation signals; a doppler effect, a relativistic effect and Shapiro delay correction are performed; the arrival time of a pulse profile datum point is obtained; an observation equation of each corresponding pulsar is formed; and independent timing and positioning of the spacecraft are realized after resolving. The pulsar navigation method can accomplish absolute positioning of the pulsars with the single detector, and the positioning accuracy is high without secular error accumulation.

The invention relates to an X-ray pulsar navigation ground test system, which comprises a signal control sub-system, an orbital data generation sub-system, a navigation database sub-system, a pulse contour extraction sub-system, a navigation parameter estimation sub-system, a large-scale dynamic effect sub-system, an X-ray pulsar signal simulation sub-system, a detector sub-system and a navigation demonstration sub-system, wherein the orbital data generation sub-system comprises a Walker constellation satellite orbit module, a lunar exploration module and a Mars exploration orbit module; the large-scale dynamic effect sub-system comprises a large-scale space effect simulation module and an in-orbit dynamic effect simulation module; and the X-ray pulsar signal simulation sub-system comprises an X-ray generator and a vacuum channel. By realistically simulating the radiation characteristics of pulsar X-ray photon signals in a large-scale dynamic environment, the performance of a pulsar navigation probe is subjected to a closed loop test, the pulsar navigation algorithm is examined, and the feasibility of the scheme design of the pulsar navigation system is verified.

An X-ray detector using a semiconductor detector, most preferably a Silicon Drift Detector, utilizes a field effect transistor or other voltage-controlled resistance to generate an output voltage proportional to its input charge (which is generated by the X-ray photons incident on the semiconductor detector). To keep the charge (and thus the output voltage) to an acceptable range—one wherein the relationship between output voltage and input charge is substantially proportional—a feedback circuit is provided between the output and input terminals, wherein the charge on the input terminal is depleted when the output voltage begins leaving the desired range. Preferably, this is done by a comparator which monitors the output voltage, and provides a reset signal to the input terminal when it begins moving out of range. Alternatively or additionally, the reset signal may be a pulse supplied to the input terminal from a pulse generator activated by the comparator.

A device for use in an imaging system is provided including a direct conversion detector element configured to convert x-ray photons into electric current. The direct conversion detector element is comprised of a cathode surface, an anode surface having a plurality of anode side edges, and a plurality of detector side surfaces connecting the cathode surface to the anode surface. The plurality of detector side surfaces each have a detector depth. The device further includes a pixel array assembly positioned on the anode surface. The pixel array assembly includes a plurality of pixel side edges. Each of the plurality of pixel side edges is immediately adjacent one of the anode side edges. A guard ring is mounted around the plurality of detector side surfaces. The guard ring includes an upper ring edge, a lower ring edge, and a ring outer surface including a guard ring height.

The present invention discloses an X-ray imaging device comprising an X-ray absorber that comprises a plurality of semiconductor layers. The plurality of semiconductor layers comprise a substrate having a backside; and at least one absorption layer adapted to absorb at least one X-ray photon impinging on the at least one absorption layer that is adapted to correspondingly generate in response to the at least one impinging X-ray photon at least one electron-hole pair; and a readout unit, wherein the readout unit is operatively coupled to the X-ray absorber such to enable readout of the at least one electron-hole pair. Additional and alternative embodiments are described and claimed.

In an apparatus and method to acquire images with the aid of high-energy photons for the examination soft tissue parts, two x-ray exposures are simultaneously obtained in different energy ranges. At least two scintillators that transmit optical photons to associated detectors are disposed in the beam path of the x-ray photons.

A target composition determination apparatus includes, an x-ray emission element for concurrently transmitting x-ray photons with a plurality of different energy levels at a target, and an x-ray detection element for receiving x-rays interacting with the target and for determining the energy levels of the received x-rays, the x-ray detection element generating at least one output signal indicative of the number of x-rays interacting with the target and the energy levels determined for each of the x-rays, and a processing element receiving the output signal and indicating the presence of at least one component material within the target using the received detection element signal and a multivariate calibration prepared for the target, the apparatus including that the output signal of the x-ray detection element is batched over a pre-selected time period to define the physical resolution of the target composition apparatus when a target is moved relative to the apparatus.

The present invention relates to an apparatus (10) for generating countable pulses (30) from impinging X-ray (12, 14) in an imaging device (16), in particular in a computer tomograph, the apparatus (10) comprising a pre-amplifying element (18) adapted to convert a charge pulse (20) generated by an impinging photon (12, 14) into an electrical signal (22) and a shaping element (26) having a feedback loop (28) and adapted to convert the electrical signal (22) into an electrical pulse (30), wherein a delay circuit (38) is connected to the feedback loop (28) such that a time during which the feedback loop (28) collects charges of the electrical signal (22) is extended in order to improve an amplitude of the electrical pulse (30) at an output (56) of the shaping element (26). The invention also relates to a corresponding imaging device (16) and a corresponding method.

The invention discloses a device for measuring an effective atomic number of a substance, which comprises an X ray source which emits X rays with different energy to a measured object, a Cerenkov detector which receives the X rays passing through the measured object and generates a first electrical signal, an energy depositing detector which receives the X rays passing through the measured object and generates a second electrical signal, and a processor which is used for acquiring the effective atomic number of the measured object according to the first electrical signal and the second electrical signal. The invention also discloses a method for measuring the effective atomic number of the substance. The method for measuring the effective atomic number of the substance by combining the Cerenkov detector and the energy depositing detector ensures that X-ray photons with high energy are more easy to form large signals during the detection of the Cerenkov detector compared with the X-ray photons with low energy, so the resolution effect of the acquired effective atomic number of the substance is enhanced.

An X-ray sensitive coating (22) for a flat panel direct conversion X-ray detector for medical or industrial imaging. A composite particle-in-binder (PIB) material (22) may contain X-ray photoconductive particles (23) such as PbO (lead monoxide) in a binder of polyimide (23). This PIB material may be prepared in precursor paste form, and applied as a coating (22) onto a thin film transistor array (26) having a storage capacitor (31) at each pixel (30). The coating (22) is cured, and an electrically conducting layer (34) is applied to the exposed surface of the coating (22), to provide a bias voltage. X-ray photons striking the photoconductive particles (23) cause localized electrical conduction proportional to the number of photons. This charges respective capacitors (31) that provide image data input to a computer.