Patent classifications
G01N2223/303
PIXEL SUMMING SCHEME AND METHODS FOR MATERIAL DECOMPOSITION CALIBRATION IN A FULL SIZE PHOTON COUNTING COMPUTED TOMOGRAPHY SYSTEM
A method and a system for a two-step calibration method for the polychromatic semiconductor-based PCD forward counting model, to account for various pixel summing readout modes for imaging at different resolutions. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at plural tube voltage settings for each detector pixel. To correct the variation of the detector response due to different PCD sub-pixel summing schemes, the embodiments calibrate forward model parameters based on the various pixel readout modes.
CALIBRATION METHOD FOR X-RAY MEASURING DEVICE
A calibration method for an X-ray measuring device includes mounting a calibration tool on a rotating table, identifying centroid positions from an output of an X-ray image detector, calculating projection transformation matrixes from the centroid positions and known relative positional intervals, repeating to identify the centroid positions from the output of the X-ray image detector and to calculate the projection transformation matrixes from the centroid positions and known relative positional intervals while the rotating table is rotated twice or more by a predetermined angle, and calculating a rotation center position of the rotating table on the basis of the projection transformation matrixes. The calibration method thereby allows easy calculation of the rotation center position of the rotating table on which an object to be measured is mounted in a rotatable manner, with the simple process.
TWO-STEP MATERIAL DECOMPOSITION CALIBRATION METHOD FOR A FULL SIZE PHOTON COUNTING COMPUTED TOMOGRAPHY SYSTEM
A method and a system for providing calibration for a photon counting detector forward model for material decomposition. The flux independent weighted bin response function is estimated using the expectation maximization method, and then used to estimate the pileup correction terms at each tube voltage setting for each detector pixel.
CT Scanner Calibration
A system and method can determine one or more CT scanner calibration parameters from a plurality of calibration object projections in a plurality of radiographs.
TOMOGRAPHIC METHOD OF DETERMINING A 3D MAP OF A CHARGE COLLECTION EFFICIENCY AND AN APPARATUS FOR PERFORMING THE METHOD
A tomographic method of determining a 3D map of a charge collection efficiency in a volume of investigation of a sample and an apparatus for performing the method. The sample has a charge carrier selecting structure and the method comprises the steps of: Arranging the sample in a beam path of a probe beam, wherein the probe beam propagates in a beam-direction which defines an axis in a laboratory frame coordinate system, Scanning the volume of investigation with an analyzing spot of the probe beam and simultaneously measuring the beam induced current and/or voltage, wherein a position of the sample arranged on a sample stage is defined by the coordinates z, y and r and a value of the beam induced current and/or voltage is determined for every position of the sample during the scanning action and Assigning every coordinate point (z, y, r) in the laboratory frame coordinate system, at which the analyzing spot of the probe beam hits the sample to a value of the beam induced current and/or voltage, which is measured for this point (z, y, r), reconstructing the 3D map of the charge collection efficiency by processing the values of the beam induced current and/or voltage determined for the coordinates (z, y, r) in the laboratory frame coordinate system with a tomographic image reconstruction algorithm so as to determine the 3D map of the charge collection efficiency in a coordinate system of the sample.
Calibration method of x-ray measuring device
A calibration method of an X-ray measuring device includes: mounting a calibration tool 102 on a rotating table 120; a moving position acquisition step of parallelly moving a position of an j-th sphere 106 with respect to a position of a first sphere 106, irradiating the calibration tool 102 with an X-ray 118, and acquiring, form an output of an X-ray image detector 124, a moving position Mj where the magnitude of a differential position Erjofa centroid position ImDisjh_Sphr_j of a projected image of the j(2£j£N)-th sphere 106 with respect to a centroid position ImDis1_Sphr_1 of a projected image of the first sphere 106 becomes equal to or less than a specified value Vx; a relative position calculation step of performing the moving position acquisition step on the remaining spheres; a feature position calculation step; a transformation matrix calculation step; a rotation detection step; a position calculation step; and a center position calculation step.
IMPROVEMENTS IN GAMMA-ACTIVATION ANALYSIS MEASUREMENTS
A method and system are disclosed to determine a concentration of one or more target elements in a sample, using gamma activation analysis comprising: simultaneously irradiating the sample and a reference material containing at least two reference elements X-rays, detecting deactivation gamma-rays from the irradiated sample and the irradiated reference material; determining the concentration of the or each target element in the sample by correcting the number of detected deactivation gamma-rays from any of the or each target element present in the irradiated sample based on the number of detected deactivation gamma-rays from the at least two reference elements, wherein the at least two reference elements have a variation in activation rate over a pre-defined X-ray end-point energy range which differs from one another.
Verification plates with automated evaluation of melt performance
An electron beam additive manufacturing system includes an electron beam source, an x-ray detection sensor configured to generate a waveform corresponding to an amount of x-rays detected by the x-ray detection sensor, and an electronic control unit comprising a processor and a non-transitory computer-readable memory, the electronic control unit communicatively coupled to the electron beam source and the x-ray detection sensor. The electronic control unit is configured to cause the electron beam source to emit an electron beam such that the electron beam impinges a verification plate, receive the waveform generated by the x-ray detection sensor in response to the x-ray detection sensor capturing x-rays emitted from the impingement of the electron beam with the verification plate, and determine a melt performance of a surface material of the verification plate based on the waveform.
X-ray imaging device
The X-ray imaging device (100) is provided with an X-ray source (1), a plurality of gratings, a moving mechanism (8), and an image processing unit (6). The image processing unit (6) is configured to generate a phase-contrast image (16) by associating a pixel value in each pixel of a subject (T) in a plurality of subject images (10) with phase values of a Moire fringe (30) at each pixel and aligning the pixel of the subject of the same position in the plurality of subject images.
SYSTEMS AND METHODS FOR ADAPTIVELY CONTROLLING FILAMENT CURRENT IN AN X-RAY TUBE
Systems and methods of adaptively controlling filament current in an x-ray tube of an imaging system include the x-ray tube having a filament being calibrated. Calibration data from the calibration of the x-ray tube is stored at the imaging system, the calibration data including a filament current value that determines a tube current value for a tube voltage value at a plurality of stations. A resistance value of the filament over a period of time is monitored. A change in the resistance value of the filament over the period of time is determined, and the filament current value of at least one of the plurality of stations is adjusted based on the changed resistance value.