WO2007076707A1 - Procede et appareil d'inspection d'objets utilisant un rayonnement multi-energie - Google Patents

Procede et appareil d'inspection d'objets utilisant un rayonnement multi-energie Download PDF

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Publication number
WO2007076707A1
WO2007076707A1 PCT/CN2006/003711 CN2006003711W WO2007076707A1 WO 2007076707 A1 WO2007076707 A1 WO 2007076707A1 CN 2006003711 W CN2006003711 W CN 2006003711W WO 2007076707 A1 WO2007076707 A1 WO 2007076707A1
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Prior art keywords
radiation
energy
different
energies
value
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PCT/CN2006/003711
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English (en)
French (fr)
Inventor
Kejun Kang
Haifeng Hu
Zhiqiang Chen
Yuanjing Li
Xuewu Wang
Chuanxiang Tang
Liming Wang
Yinong Liu
Yaohong Liu
Li Zhang
Jianmin Li
Huaqiang Zhong
Jianping Cheng
Huaibi Chen
Hua Peng
Yali Xie
Junli Li
Ning Kang
Qinghua Li
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Tsinghua University
Nuctech Company Limited
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Publication of WO2007076707A1 publication Critical patent/WO2007076707A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/04—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and forming images of the material
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01N23/083—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays
    • G01N23/087—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays using polyenergetic X-rays
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01N23/083—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption the radiation being X-rays
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/42—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4208—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector
    • A61B6/4241—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment with arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a particular type of detector using energy resolving detectors, e.g. photon counting
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/48—Diagnostic techniques
    • A61B6/482—Diagnostic techniques involving multiple energy imaging
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
    • G01N23/02—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material
    • G01N23/06—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by transmitting the radiation through the material and measuring the absorption
    • G01V5/20—
    • G01V5/224—

Definitions

  • the present invention relates to radiation inspection of large objects, and more particularly to a method and apparatus for identifying materials and forming images in large and medium-sized objects such as shipping and air containers using ionizing radiation having various energies. Background technique
  • the existing general cargo inspection system for radiation imaging is generally to allow the single-energy ray to interact with the object to be inspected, and to detect the ray that has been applied to the object to be imaged. Such a system can reflect changes in the shape and mass thickness of the object being inspected, but it cannot identify the material of the object.
  • ⁇ -in( ⁇ ) ... (1 )
  • m is the mass thickness of the object and ⁇ is the equivalent mass attenuation coefficient of the material in the corresponding energy interval of the X-ray, which is related to the material and radiant energy of the object, /'
  • the radiation of a single energy cannot simultaneously distinguish the influence of the material and the thickness of the object, but it can detect the probability that the X-ray with different energy interacts with the object to obtain a physical reaction with the object. Determine the material properties of the object.
  • material identification of the object to be inspected is achieved by X-rays of two energies.
  • the X-ray energy used is not enough to penetrate goods of high quality and thickness, which is not suitable for large and medium-sized object inspections, such as containers and air boxes.
  • Patent Document 1 US Pat No. 5,524,133
  • the system uses two sets of fixed X-ray sources and two sets of detector arrays corresponding thereto.
  • the two X-ray generators provide two X-rays of different energies.
  • the energy of one X-ray is much higher than the other X.
  • the energy of the ray for example, the energy of one X-ray is 5 MeV, and the energy of the other X-ray is lMev.
  • the average atomic number of the material is determined by looking up the ratio of the two probing results in a pre-created lookup table. Due to the complicated structure and high cost brought about by the two sets of X-ray emitting devices and two sets of detector arrays, this method has not been widely used since its introduction in 1993.
  • Patent Document 2 (WO 00/437600) and Patent Document 3 (US Pat No. 6,069,936) propose to use an X to generate an X for an accelerator.
  • the beam is modulated to obtain two X-rays of different energy spectra.
  • the technical idea of the above Patent Document 2 and Patent Document 3 is to obtain X-rays having different energies using a single accelerator.
  • the difference between the energy spectra of the two X-rays obtained by filtering the X-rays through the filter is limited, resulting in a limited range of accurate material identification.
  • Patent Document 4 proposes a method for obtaining dual-energy X-rays based on traveling wave LINAC, which shows the feasibility of obtaining a single X-ray of different energies by a single accelerator.
  • Patent Document 5 proposes the use of a high energy dual energy method to detect an object containing a high Z material.
  • Patent Document 5 gives a statistical function, and then adjusts the threshold according to the selected standard deviation to balance the sensitivity and accuracy, and then issues an alarm when a high Z material whose atomic number is higher than a predetermined value is found.
  • Patent Document 1 and Patent Document 5 mention that the ratio of the two detection results is used to perform a look-up table to determine whether the object to be inspected contains suspicious material.
  • the error rate of this method is very high due to the detection error, when the mixed condition of the object to be inspected is serious, or when the object to be inspected is a thin material. .
  • the invention discloses a method and a device for inspecting an object by using radiation with multiple energies, so that a beam of rays with multiple energies interacts with an object, and the calculation and analysis based on curve fitting are realized by using the result of the interaction.
  • a method of inspecting an object using radiation having a plurality of energies comprising the steps of:
  • Further energy properties of the object are determined using a set of functions appropriate to the energy interval in the energy interval corresponding to the information. .
  • the information further includes mass thickness information of the object.
  • the calibration function is a fitted function of values detected after interaction of radiation having different energies with known materials.
  • the number of radiations that interact with known materials for fitting the calibration function is not less than the number of radiations that interact with the object being inspected.
  • the plurality of energies are at least three different energies or energy spectra.
  • the detected value after interaction with the object is a value of the transmitted intensity after the radiation penetrates the object.
  • the energy interval refers to a larger interval between the function value of the detected value of the radiation interval of the energy interval and the function value of the detected value of the other material compared with the other regions.
  • the function group makes the small difference between the detected values of different materials become obvious in an energy interval, and at the same time, the influence of the undifferentiated portion can be reduced.
  • the function group refers to a material having a different thickness, using a different function.
  • the model is segmented.
  • the source of radiation of the radiation is a radioisotope.
  • the source of radiation of the radiation is an accelerator.
  • the radiation source of the radiation is an X-ray machine.
  • a method of inspecting an object using radiation having a plurality of energies comprising:
  • a part of the detection value is substituted into a predetermined calibration function to determine the mass thickness of the object; according to the thickness of the mass, the weights of the different energy detection values are selected, and the image is fused to obtain a more accurate gray image.
  • the method further comprises the step of: converting the gray level of the grayscale image to a corresponding color level in the color image.
  • said plurality of energies are at least 2 different energies.
  • the determination of the mass thickness of the object is judged based on the actual attenuation of the radiation.
  • the weighting of the different energy detection values is determined, that the thinner the material, the smaller the weight of the high-energy radiation detection value, and the greater the weight of the low-energy radiation detection value; for the thicker material, the low-energy radiation detection The smaller the weight of the value, the greater the weight of the high-energy radiation detection value.
  • an apparatus for implementing the method of inspecting an object using radiation having a plurality of energies comprising:
  • An array of detector modules suitable for simultaneously detecting a plurality of radiations having different energies; a processor coupled to the array of detector modules for processing the detected values of the interaction of radiation and objects having different energies to obtain an object Material properties and/or grayscale images of the object;
  • a control system is coupled to the source of radiation for varying operating parameters of the source of radiation at predetermined timings.
  • said plurality of different energies are at least 3 different energies or energy spectra.
  • the plurality of different energies are at least 2 different energies or energy spectra.
  • the detector array is a multi-layer polycrystalline detector, which is composed of different crystals.
  • the detector array there is a filter spacer between different crystals.
  • the source of radiation is a radioisotope.
  • the source of radiation is a combination of radioisotopes of different elements, which are sequentially rotated through the slits of the collimator to emit radiation of different energies using different radioisotopes.
  • the source of radiation is an accelerator that emits continuous energy spectrum rays that are dominated by different energies.
  • the accelerator includes an energy spectrum modulator for energy spectrum modulation placed at the front end of the radiation outlet.
  • the radiation source is an X-ray machine.
  • the X-ray machine includes an energy spectrum modulator for energy spectrum modulation placed at the front end of the radiation outlet.
  • the energy spectrum modulator is in the shape of a disk, the blades being composed of different modulating materials, and the blades are rotated about the axis at a timing corresponding to the respective beam of energy radiation.
  • the energy spectrum modulator synchronizes the radiation source beam out of the detector acquisition signal by a control system that transmits a trigger signal to the radiation source and a controller that transmits the acquisition signal to the detector.
  • control system when the control system receives the trigger signal, it will immediately send a signal corresponding to different energies to the radiation source to operate the radiation source in the desired working state.
  • the detected value of the various energies is a value of the transmitted intensity after the radiation penetrates the object.
  • the detected value of the various energies is a value of the transmitted intensity after the radiation penetrates the object.
  • the function of the piecewise fitting function obtained from the detected value of the known material is used as the comparison threshold, so that the whole judgment is based on the actual measured value, and the direct interpolation of the prior art is reduced by the second judgment and the special processing for the thickness. And the error brought by the look-up table, thus improving the accuracy of material resolution.
  • the X-rays of different energies interact with the object to obtain the detected values, and the data of the collected data of the high energy and the low energy are respectively given different weighting factors, and the material with a large difference in the mass thickness of the object to be inspected is also clearly obtained. Grayscale images and color images with richer levels.
  • X-rays generated by the accelerator are modulated according to different materials, and different X-rays with different energies are modulated by different modulation materials to obtain the best energy spectrum modulation effect, that is, the best material resolution energy spectrum is obtained. This reduces the error caused by the dispersion of the ray energy spectrum to the final resolution.
  • Multi-layer detectors can further enhance the detection of X-rays with different energies, improving detection and detection accuracy.
  • FIG. 1 is a schematic diagram of an apparatus for inspecting an object using X-rays having various energies, in accordance with an embodiment of the present invention
  • FIG. 2 is a top plan view of an apparatus for spectrally modulating rays having different energies in accordance with an embodiment of the present invention
  • FIG. 3 is a timing diagram of signals transmitted by an energy spectrum modulator to an accelerator control system
  • FIG. 4 is a schematic diagram of a detector for realizing accurate multi-energy radiation detection according to an embodiment of the present invention
  • Figure 5 is a given functional relationship between radiant energy and material properties and material mass thickness over the entire energy range
  • Figure 6 is a given functional relationship curve between radiant energy and material properties and material thickness in an energy interval that is advantageous for distinguishing high Z materials
  • Figure 7 is a general flow chart for material resolution using multiple detected values of different energy rays.
  • Figure 8 is a flow chart of a method of adjusting a fused image using different mass thickness information. detailed description
  • the present invention when inspecting container cargo, it is necessary to generate higher energy X-rays from the accelerator so that the radiation has sufficient energy and dose to be detected by the detector after the container cargo is penetrated.
  • the key point is the need for an accelerator. A plurality of X-rays having different energies are generated and interact with the same position of the object to be inspected, and then accurately detected by the detector.
  • Fig. 1 is a schematic diagram of an apparatus for inspecting an object such as a container cargo using X-rays having various energies according to an embodiment of the present invention.
  • the accelerator 1 can generate X-rays having different energies by changing the operating parameters.
  • the change in the operating parameters of the accelerator 1 is achieved by the control system 4 in the device.
  • the corresponding operating state of the accelerator 1 when X-rays of various energies are generated is stored in the control system 4.
  • the control system 4 receives the trigger signal 3, it immediately sends a control signal corresponding to the X-rays of various energies to the accelerator 1 to operate the accelerator 1 in the desired working state.
  • the accelerator 1 completes the generation of X-rays of a specific energy in the operating state required by the control system 4, it returns to the control system 4 to complete the command.
  • the X-ray generated by the accelerator 1 is modulated by the energy spectrum modulator 2 to obtain an optimized X-ray. Then, a plurality of X-rays having different energies respectively interact with the same position in the object 7 to be inspected.
  • the detector 8 is controlled by the controller 9 to detect X-rays that have passed through the object to be inspected.
  • the detection signal 12 of the detector 8 is transmitted to the workstation 13 via the network.
  • Data processing is performed at the workstation U to obtain grayscale images and material properties of the object to be inspected.
  • the X-rays are generated by electron beam shooting accelerated by the accelerator 1, and after being collimated by the collimator 6A, a fan-shaped X-ray beam is obtained.
  • the collimators 6B and 6C shown in Fig. 1 suppress scattered radiation during measurement.
  • the triggering of the accelerator and the acquisition of the detector are achieved by issuing the trigger signal 3 and the signal 10.
  • the energy spectrum modulator 2 modulates the X-rays of different energies with different energy spectrum modulation materials.
  • the energy spectrum modulator is circular, and the axis of the spectrum modulator 2 is a grid-like air shaft.
  • the blades that rotate about the axis are composed of different modulating materials.
  • the trigger signal 3 is sent to the controller of the accelerator 1 for maintaining synchronization between the spectrum modulator 2 and the accelerator 1.
  • X-rays with different energies are spectrally modulated by the blades of the corresponding spectrally modulated material.
  • different modulation schemes and rays with different energies will have completely different modulation effects.
  • the low-Z material should be selected as the energy spectrum modulation material of the X-ray, such as boron, polyethylene and other hydrogen-rich materials. Organic materials, etc.
  • High-Z materials absorb energy with a ray of several hundred KeV, so when the lower limit of the X-ray energy distribution energy range is higher than a lower energy threshold (such as ⁇ 300 keV), high Z material should be selected as the X-ray.
  • Energy spectrum modulation materials such as Pb, W, U, etc.
  • the X-rays of 3 to 6 MeV generated by the accelerator 1 are composed of a first portion 14 and a second portion 15.
  • the first part 14 can be made of a modulating material polyethylene, and the second part 15 can be made of a modulating material Pb.
  • the first portion 14 absorbs higher energy rays while the second portion 15 absorbs lower energy scattering components.
  • the modulating blade 16 used may be selected from a polymer material.
  • the modulation blade 17 can be made of a modulation material. As shown in Fig. 2, the above three types of blades are periodically arranged around the circumference of the shaft so that the X-rays having the respective energies are spectrally modulated every time a predetermined angle is rotated.
  • the modulation blades of the energy spectrum modulator rotate uniformly around the central axis 18.
  • the signal is triggered when the first type of modulated blade is rotated to a fixed position in front of the ray plane.
  • Fig. 3 shows a timing chart for generating the above-described timing signals.
  • the accelerator 1 continuously generates a plurality of X-rays having different energies, and the time interval between each of the emitted rays is t. In the time interval ⁇ , the next modulated blade of the spectrum modulator 2 is just turned to the fixed position. Then, after the time t 2 , when the first type of modulated blades are rotated to the same fixed position, the signal is again signaled to generate the emission period of the next continuous pulsed beam.
  • the trigger signal is also sent to the detector's control system, and after a certain delay, the detector 8 starts to collect the signal. In this way, time synchronization between the various components is achieved.
  • the detector can be a multi-layer polycrystalline detector.
  • the above accelerator can be replaced with a radioactive isotope.
  • SP a combination of multiple isotopes, using different radioactive isotopes to emit rays of different energies through the slits of the collimator at a predetermined timing.
  • the first sensing portion 41 may be configured by a Csl crystal according to the level of the signal of the corresponding energy signal of the different materials, and the first sensing portion 41 is used to collect the light with a lower energy, and the output signal is The first output portion 42 is output. Other energetic rays will pass through the first sensing portion 41, and the first output portion 42 reaches the filtering portion 43.
  • the filtering portion 43 is a filter 06 003711 piece, used to filter low-energy rays such as Compton scattering.
  • the material of the filtering portion 43 can be selected to be Pb or W.
  • the second sensing portion 44 can select a CWO crystal, and most of the rays of the high energy component are precipitated in the second sensing portion 44.
  • the signal of the second sensing portion 44 is output through the second output portion 45.
  • the detection signal obtained by the detector is converted to a 16-bit binary number by the ADC and transmitted to the processing station 13.
  • the data is processed by the image processing module.
  • a set of functions in all energy intervals are calibrated to form a curve representing the relationship between the function groups.
  • the functions in the function group can be arbitrarily selected, for example, the value A of the abscissa and the value P of the ordinate are calculated by the following formulas (2) and (3):
  • the detected values of several energy of the object to be inspected are substituted into the function of the calibrated function group, and then the obtained function value is compared with the function value of the calibrated known material to preliminarily determine the material of the object to be inspected.
  • the optimal energy resolution interval is different, and the function models selected for each energy interval are also different.
  • the figure shows the corresponding functional relationship curve for the energy range suitable for distinguishing heavy metals. It can be seen that heavy metal can be well distinguished by using the specific function curve of the energy interval. Therefore, according to the material range of the material judged for the first time, the material property can be judged more accurately by further using the appropriate energy combination form and the function group of the corresponding segment.
  • the object When the object is an object of small thickness, it will affect the accuracy of the identification of the material.
  • the function value of the selected function group falls within a certain area of the coordinate system, or the attenuation is small, it can be considered that the mass thickness of the object is small.
  • the function value corresponding to the object having a small mass thickness is used, and the detection value is used. Further processing is performed to ensure the accuracy of the identification.
  • the functional relationship of the objects of small mass and thickness used is obtained by fitting the calibration data of the actual material.
  • Fig. 7 shows a method flow for judging material properties using a plurality of energies using six kinds of energies as an example.
  • step S110 X-rays of six kinds of energies are interacted with known materials, given any three of them (of course, Here, it is also possible to use a function function of two or four kinds of less than six kinds, not less than two kinds of ray numbers) to calibrate the material. In this way, classification curves for various known materials can be established.
  • step S120 the object to be inspected is scanned with X-rays having six different energies, and the detected values of the X-rays of the six different energies of the object to be inspected are collected by the detector.
  • step S130 the X. rays are divided into two groups according to energy, for example, the X-ray having the first energy, the X-ray having the third energy, and the X-ray having the fourth energy are divided into the first group, and will have The X-ray of the second energy, the X-ray having the fifth energy, and the X-ray having the sixth energy are divided into the second group.
  • step S130 and step S140 the detected values of the three energies of each group are substituted into the above-mentioned calibration function to initially judge the material properties. For example, it is judged whether or not the material a is contained in the object to be inspected by the detection value of the X-ray of the first group, and whether the material 13 is contained in the object to be inspected is determined by the detected value of the X-ray of the second group.
  • step S150 if the determination results using the two sets of X-rays are Cu and W, respectively, the detection values of the energy intervals more suitable for Cu and W are respectively selected, and the material properties are further determined by the function group suitable for the energy segments.
  • a beam of radiation in an energy range suitable for its optimum resolution such as X-rays having a second energy, having a third A given set of values of the detected values of the X-rays of energy and the X-rays of the fourth energy are used to further determine the material properties of material a.
  • a plurality of images obtained by scanning the object to be inspected by X-rays having different energies may be fused to obtain a scanned image of better quality.
  • Figure 8 is a flow chart of a method of adjusting an image using different mass thickness information.
  • the image fusion process utilizes high and low energy rays to different attenuation characteristics of different mass thicknesses of the object, and the fusion of the two detection values results in a clear image in a wide range of mass thicknesses.
  • the material properties of the object to be inspected are determined, for example, whether the mass thickness of the object to be inspected is thick or thin.
  • the approximate range of the mass thickness of the object is judged, that is, when the attenuation is severe, for example, less than a predetermined threshold, an object considered to be a high-quality thickness, when the attenuation is small, for example, greater than a predetermined threshold, is considered It is an object of low quality thickness.
  • step S230 for objects of low mass thickness, the high energy data is given a smaller weight factor, such as 30%; and the low energy data is given a larger weighting factor, such as 70%.
  • step S240 for the object having a large mass thickness, a high weighting factor is given to the high energy data, such as 70%; and the low energy data is given a smaller weighting factor, such as 30%.
  • step S250 the high energy image and the low energy are synthesized according to the weighting factor given above. Comparing with the corresponding predetermined threshold, the high energy and low energy data are respectively assigned different weight factors, thereby synthesizing the gray information of the final image.
  • the detected images have different image characteristics after interacting with objects of different mass thicknesses
  • objects having a large difference in mass thickness between the respective portions are It is also possible to get a very clear grayscale image.
  • the accelerator generates X-rays of not less than three different energies, which respectively act on the same object, and the detector detects the rays passing through the object, and then analyzes the detection results to realize the material properties of the object to be inspected.
  • the detector detects the rays passing through the object, and then analyzes the detection results to realize the material properties of the object to be inspected.
  • the accelerator can generate multiple X-ray energy spectra with different energy ratios. Since the X-ray energy generated by the accelerator has a wide spectrum of energy spectrum, the X-rays of other energies occupy a relatively large proportion, which will affect the accuracy of material identification. Therefore, it is necessary to improve the X-ray spectrum by means of spectrum modulation.
  • the proportion of X-rays of energy For different energy X-rays, different materials are used for modulation to obtain an optimized X-ray energy spectrum.
  • the use of radioactive elements that are not available as a source of energy for different energies may not require spectral modulation, but the range of energies that may be selected is not continuous.
  • the present invention uses an energy spectrum modulator to spectrally modulate the X-rays produced by the accelerator. Different energies, different materials are used for energy spectrum modulation, so that the energy spectrum that best fits the material is obtained.
  • the energy range of the X-ray energy spectrum distribution is different, and the suitable energy spectrum modulation materials are also different.
  • the low Z material should be selected as the energy spectrum modulation material of the beam X-ray, such as B. , polyethylene and other hydrogen-rich organic materials.
  • a certain energy threshold such as ⁇ 3MeV
  • high Z material should be selected as the energy spectrum modulation material of the X-ray, such as Pb, W. , U, etc., but you can also choose medium Z materials such as Cu.
  • a layered detector is used to detect multiple X-rays with different energy, so as to accurately obtain the signal values of the rays of various energies and objects, so that each can be accurately distinguished.
  • Different detection crystals are sensitive to X-rays of different energies and exhibit different response characteristics. Rays of different energies are generated and collected in different detection crystals, and a comprehensive processing method is applied to the detection signals of various energies to further utilize signals of various energies.
  • the range of ray energies that are most pronounced due to the difference in material and ray effects is different. Therefore, for different materials, in order to accurately obtain the material properties of the material, the specific energy range that is useful for distinguishing the material resolution should be used, and the lowest threshold and the highest energy threshold of the energy range are given in advance.
  • the energy range that is most suitable for distinguishing between organic matter and inorganic matter is: 0.3MeV ⁇ 3MeV and the energy range most suitable for distinguishing heavy metals is: lMeV ⁇ 4MeV, corresponding to different energy intervals, the processing function used is also different.
  • the use of X-rays of different energies to achieve the resolution of material properties is essential to accurately detect the difference between X-rays of different energies and objects.
  • the mass thickness of the object is analyzed. Since the selected detection energy is usually higher than a certain value, it is determined that the corresponding is unlikely to be too small, so the mass thickness of the object can be judged based on the region of the coordinate system in which the function value is located. When the mass thickness of the object to be inspected is relatively small, the statistical inherent in the radiation physics becomes not negligible. For the X-rays of the continuous energy spectrum produced by the accelerator, the characteristics of the rays and the action of the object in the dominant energy segment will not be easily expressed.
  • the present invention can be variously modified, for example, an X-ray machine can be used instead of the above-described accelerator. In this case, it is necessary to arrange the energy spectrum modulator of the present invention at the radiation output end of the X-ray machine.

Description

利用具有多种能量的辐射检查物体的方法及其设备 技术领域
本发明涉及对大型物体进行辐射检查，特别涉及利用具有多种能量的 致电离辐射对海运、航空集装箱等大中型客体中的材料进行识别、形成图 像的方法及设备。 背景技术
'现有通用的釆用辐射成像的货物检查系统一般都是让单能射线与被 检物体相互作用后， 探测与被检物体作用后的射线来得到图像。这种系统 能够反映出被检物体的形状和质量厚度的变化，但却不能对物体的材料进 行识别。
众所周知， 不同能量的 X射线与物体相互作用时， 其产生的物理反 应与物体的材料属性有关。 X射线与相同材料发生的相互作用随 X射线 的能量变化。在不同的能量区域， 光电效应、康普顿效应和电子对效应产 生的几率分别占主要地位。 而这三种物理效应又与材料的原子序数相关。
下式 （1 ) 给出了 X射线与物体相互作用：
〃 = -in( ~) … （1 ) 其中 m为物体的质量厚度， ^为 X射线的相应能量区间中材料的等效质 量衰减系数， 它与物体的材料及辐射能量有关， /'为具有某种能量的 X射 线与被检物体相互作用后的强度值， /。为具有该能量的 X射线未与被检 物体相互作用时的强度值。
可见，利用单一能量的射线不能同时区分物体的材料和质量厚度的影 响， 但可以通过探测具有不同能量的 X射线与物体发生作用后的射线， 得到它与物体发生了相关物理反应的概率， 从而判断物体的材料属性。在 小型行李物品检查系统中， 通过两种能量的 X射线实现了对被检物体的 材料识别。 但使用的 X射线能量根本不足以穿透质量厚度较大的货物， 这在大中型的客体检查中不适用， 如集装箱， 航空箱等。
较早以前， 专利文献 1 (U.S. Pat No. 5,524,133〉 提出了利用两束能 量不同的高能 X射线分辨大型客体的材料属性的技术思路。 该系统中使 用两套固定的 X射线源及与其相对应的两组探测器阵列， 两个 X射线发 生器提供不同能量的两束 X射线， 一束 X射线的能量远高于另一束 X射 线的能量， 例如， 一束 X射线的能量是 5Mev， 而另一束 X射线的能量是 lMev。 利用两个探测结果的比值在预先创建的查找表中查找来判断材料 的平均原子序数。 由于两套 X射线发射装置和两组探测器阵列带来的结 构复杂、 成本昂贵等问题， 这种方法自 93年提出后一直没有得到广泛的 应用。
为了解决上述两套系统带来的结构复杂、成本昂贵的问题， 专利文献 2 (WO 00/437600)及专利文献 3 (U.S. Pat No. 6,069,936)提出通过用滤 波器对在一台加速器产生的 X射线束进行调制来获得不同能谱的两束 X 射线。上述专利文献 2和专利文献 3的技术思路均是要利用单一加速器得 到具有不同能量的 X射线。 但是通过滤波器对 X射线进行滤波获得的两 束 X射线的能谱之间的差异有限， 导致准确的材料识别的范围受到限制。
另夕卜， 专利文献 4 (WO 2004/030162 A2)提出了基于行波 LINAC获 得双能 X射线的方法， 它表明.了单加速器获得不同能量的两束 X射线的 可行性。
专利文献 5 (WO 2005/084352 A2) 提出了利用高能双能的方法来探 测含有的高 Z材料的物体。专利文献 5给出了一个统计函数， 然后， 根据 所选择的标准方差来调整阈值， 用以平衡灵敏度和精确度， 进而在发现原 子序数高于预先设定值的高 Z材料时发出警报。
如上所述的方法均是使用两种能量进行材料识别的方法，其中利用两 种能量下的探测结果进行计算判断是否被检物体包含可疑材料。例如专利 文献 1和专利文献 5提到利用两次探测结果的比值进行査表来判断是否被 检物体包含可疑材料。 但是， 受所釆用的 X射线的两种能量的限制， 由 于存在探测误差， 在被检物体的混杂情况严重时， 或是被检物体为薄材料 时， 这种方法的错判率非常高。 另外， 根据两次测量值比值判断的方法， 同一个函数形式无法区分不同材料之间的测量值差别，同时存在不同材料 的比值相同的可能。这都将造成检测结果不准确。而且， 在两种能量的情 况下， 由于其灵敏度高的材料区间有限， 无法同时对低 Z材料和高 Z材 料进行准确识别。 发明内容
本发明公开了一种利用具有多种能量的辐射检查物体的方法及其设 备， 使具有多种能量的射线束与物体相互作用， 利用相互作用的结果进行 基于曲线拟合的计算和分析， 实现了对较大范围内不同材料的识别， 进而 实现对物体的非侵入性检査。
在本发明的一个方面，提出了一种利用具有多种能量的辐射检查物体 的方法， 包括步骤：
利用具有多种能量的辐射与被检物体相互作用；
探测并记录具有不同能量的辐射与被检物体相互作用后的探测值； 通过将探测值的一部分代入预定的标定函数中，来获取包括物体的初 步材料属性的信息；
在与所述信息相对应的能量区间利用适合该能量区间的函数组，判断 物体的进一步材料属性。 .
优选地， 所述信息还包括物体的质量厚度信息。
优选地，所述的标定函数是在具有不同能量的辐射与已知材料相互作 用后探测的值的拟合函数。
优选地，所述的用于拟合标定函数的与已知材料相互作用的辐射的数 目不小于与被检物体相互作用的辐射的数目。
优选地， 所述的多种能量至少为 3种不同的能量或能谱。
优选地，所述的与物体相互作用后的探测值为辐 穿透物体后的透射 强度值。 优选地， 所述的能量区间， 是指该能量区间的辐射与一材料相互作用 后的探测值的函数值与其他材料的探测值的函数值的差别相比于其它区 间更大的区间。
优选地， 所述函数组， 在一能量区间内可令不同材料的探测值间的细 小差别变得明显， 同时能够降低无差别部分的影响。
优选地， 所述函数组， 是指对应厚度不同的材料， 使用不同的函数处 理模型分段处理。
优选地， 所述的辐射的辐射源为放射性同位素。
优选地， 所述的辐射的辐射源为加速器。
优选地， 所述的辐射的辐射源为 X光机。
在本发明的另一方面，提出了一种利用具有多种能量的辐射检查物体 的方法， 包括：
利用具有多种能量的辐射与被检物体相互作用；
探测具有不同能量的辐射与被检物体相互作用后的探测值，以形成与 不同能量的辐射相对应的图像；
将一部分探测值代入预定的标定函数中， 以判断物体的质量厚度； 根据质量厚度， 选择不同能量探测值的权重， 对图像进行融合处理， 得到更准确的灰度图像。
优选地， 所述方法还包括步骤： 将所述灰度图像的灰度等级转换到彩 色图像中相对应的色彩级别。
优选地， 所述的多种能量至少为 2种不同的能量。
优选地， 所述对物体的质量厚度的判断， 是根据辐射的实际衰减情况 进行判断的。
优选地， 所述选择不同能量探测值的权重， 是指对于越薄的材料， 高 能辐射探测值所占权重越小， 低能辐射探测值所占权重越大； 对于越厚的 材料， 低能辐射探测值所占权重越小， 高能辐射探测值所占权重越大。
在本发明的又一方面，提出了一种用于实施所述的利用具有多种能量. 的辐射检査物体的方法的设备， 包括：
一组可产生多种具有不同能量的辐射的辐射源；
一种适合同时探测多种具有不同能量的辐射的探测器模块阵列； 一个与探测器模块阵列相连的处理器，用于对具有不同能量的辐射与 物体相互作用后的探测值进行处理， 得到物体的材料属性和 /或产生物体 的灰度图象；
一个控制系统， 与所述的辐射源连接， 用于按照预定的时序改变辐射 源的工作参数。 '
优选地， 所述的多种不同能量至少为 3种不同的能量或能谱。 优选地， 所述的多种不同能量至少为 2种不同的能量或能谱。
优选地，所述探测器阵列为多层多晶体探测器，由不同晶体复合而成。 优选地， 所述探测器阵列中， 不同晶体之间有滤波片隔幵。
优选地， 所述辐射源为放射性同位素。
优选地， 所述的辐射源是一种不同元素的放射性同位素的组合， 利用 不同的放射性同位素按时序轮流通过准直器的狭缝而发出不同能量的辐 射。
优选地，所述辐射源是一种可发射出不同能量占优的连续能谱射线的 加速器。
优选地，所述加速器包括一个置于辐射出口前端的用于能谱调制的能 谱调制器。
优选地， '所述辐射源为 X光机。
优选地， 所述 X光机包括一个置于辐射出口前端的用于能谱调制的 能谱调制器。
优选地， 所述能谱调制器呈轮盘状， 由不同调制材料构成叶片， 叶片 按与相应能量辐射束相对应的时序围绕轴旋转。
优选地，所述能谱调制器通过发射触发信号到辐射源的控制系统以及 发射采集信号到探测器的控制器使辐射源出束与探测器采集信号同步进 行。
优选地， 所述控制系统接收到触发信号时， 将立即给辐射源发送各种 不同能量对应的信号， 让辐射源工作在所需的工作状态下。
优选地， 所述的各种能量的探测值为辐射穿透物体后的透射强度值。 通过具有多种能量的 X射线来识别物体的材料， 能够针对不同的材 料， 釆用各自最佳的区分能量区间。这样可以很大程度地提高材料分辨的 正确率。 同时， 由于物体的材料属性和质量厚度的综合影响， 容易造成探 测结果曲线的交叉。 但是， 通过对具有多种能量的 X射线的探测值拟和 得到特定曲线用于材料识别，有助于提高材料分辨的准确率。并且根据已 知材料的探测值得到的分段拟合函数的函数作为比较阈值，让整个判断基 于实际的测量值， 通过二次判断和针对厚度的特殊处理， 减小了现有技术 中直接插值和查表带来的误差， 从而提高了材料分辨的准确率。 把不同能量的 X射线与物体相互作用后得到探测值， 给高能量和低 能量下釆集的数据分别赋予不同的权重因子，实现对被检物体的质量厚度 相差比较大的材料同样得到很清晰的灰度图像和色阶较丰富的彩色图像。
对加速器产生的 X射线， 根据不同材料分辨对象， 利用不同的调制 材料对具有不同的能量的 X射线进行能谱调制， 从而得到最佳能谱调制 效果， 即得到最佳的材料分辨能谱。这样降低了因为射线能谱分散给最终 分辨结果带来的误差。
多层的探测器能够进一部提高针对具有不同能量的 X射线的探测效 果， 提高了探测效果和探测精度。 附图说明
图 1是根据本发明实施例的利用具有多种能量的 X射线检查物体的 设备的概况图；
图 2 是根据本发明实施例对具有不同能量的射线进行能谱调制的装 置的俯视图；
图 3示出了能谱调制器给加速器控制系统发送的信号时序； 图 4 是根据本发明实施例的实现精确的多能射线探测釆用的探测器 的示意图； ·
图 5是在整个能量区间内，辐射能量与材料属性及材料质量厚度之间 的一种给定的函数关系曲线；
. 图 6是在有利于区分高 Z材料的能量区间内，辐射能量与材料属性及 材料量厚度之间的一种与图 5不同的给定的函数关系曲线；
图 7是利用多束不同能量射线的探测值实现材料分辨的总流程图；以 及
图 8是利用不同质量厚度信息调整融合图像的方法的流程图。 具体实施方式
按照本发明， 在检査集装箱货物时， 需要由加速器产生较高能量的 X 射线，使得射线有足够的能量和剂量在穿透集装箱货物后仍然能被探测器 探测到有效信号。要实现对被检物体材料的分辨， 关键之处是需要加速器 产生多束具有不同能量的 X射线， 并且与被检物体的同一位置发生相互 作用， 然后被探测器精确的探测。
图 1是根据本发明实施例的利用具有多种能量的 X射线检查诸如集 装箱货物之类的物体的设备的概况图。 图 1中， 加速器 1通过改变工作参 数可以产生具有不同能量的 X射线。 加速器 1的工作参数的改变是通过 设备中的控制系统 4来实现的。
加速器 1产生各种能量的 X射线时相应的工作状态被存储在控制系 统 4中。 当控制系统 4 接收到触发信号 3后， 立即给加速器 1发送与各 种不同能量的 X射线相对应的控制信号， 让加速器 1工作在所需的工作 状态下。 当加速器 1完成控制系统 4要求的工作状态下的特定能量的 X 射线的产生后， 将返回给控制系统 4 一完成指令。 加速器 1产生的 X射 线经过能谱调制器 2调制， 得到优化后的 X射线。 然后， 多束具有不同 能量的 X射线分别与被检物体 7中的同一位置发生相互作用。由控制器 9 控制探测器 8探测穿透被检物体后的 X射线。 探测器 8的探测信号 12通 过网络传送到工作站 13。 在工作站 U进行数据处理， 以得到被检物体的 灰度图像和材料属性。
X射线由加速器 1加速的电子束打靶产生， 经过准直器 6A准直后， 得到扇形的 X射线束。 另外， 图 1中所示的准直器 6B和 6C抑制了测量 过程中的散射辐射。
因为需要利用不同的调制材料对相应能量的射线进行能谱调制，所以 通过发出触发信号 3和信号 10来实现加速器出束和探测器采集的同步。
根据加速器 1产生的 X射线， 能谱调制器 2针对不同能量的 X射线 釆用不同的能谱调制材料进行调制。如图 2中所示，能谱调制器是圆形的， 并且能谱调制器 2的轴心是网格状的镂空中轴。由不同的调制材料构成围 绕轴旋转的叶片。触发信号 3发送给加速器 1的控制器， 用于保持能谱调 制器 2与加速器 1之间的同步。 这样， 具有不同能量的 X射线由相应能 谱调制材料构成的叶片进行能谱调制。根据射线与物体的作用不仅跟射线 的特性有关， 同时跟物体的材料属性相关的特点， 不同的调制方案与具有 不同的能量的射线将得到完全不同的调制效果。
例如， 由于低 Z材料对能谱中较高能量的射线吸收比较厉害， 因此， 当 X射线能谱分布能量范围下限高于某一能量较高的阈值 （如〜 3MeV) 时， 应该选择低 Z材料作为该束 X射线的能谱调制材料， 如硼、 聚乙烯 及其他富氢有机材料等
高 Z材料对能量在几百 KeV的射线吸收厉害， 所以当 X射线能谱分 布能量范围下限高于某一能量较低的阈值 （如〜 300keV) 时， 应该选择 高 Z材料作为该束 X射线的能谱调制材料， 如 Pb、 W、 U等。
图 2示出了根据本发明实施例对具有不同能量的 X射线进行能谱调 制的能谱调制器的俯视图。 对加速器 1产生的 3〜6MeV的 X射线， 采用 的调制叶片由第一部分 14和第二部分 15组成。 第一部分 14可选用调制 材料聚乙烯， 第二部分 15可选用调制材料 Pb。 第一部分 14吸收较高能 量的射线， 而第二部分 15吸收能量较低的散射成分。
针对能量为〜 9MeV的射线， 采用的调制叶片 16可选用高分子材料。 针对能量 200KeV〜lMeV的射线，调制叶片 17可选用调制材料\ 。如图 2所示， 上述的三类叶片周期性地绕轴圆周排列， 使得每转过预定的角度 就对具有相应能量的 X射线进行能谱调制。
能谱调制器的调制叶片围绕中轴 18匀速旋转。 当第一类调制叶片旋 转到射线平面前的一固定位置时， 触发信号。 图 3示出了产生上述的时序 信号的时序图。 加速器 1连续产生具有不同能量的多束 X射线， 发射每 束射线时间间隔为 t 在时间间隔 ^的时间里， 能谱调制器 2的下一个调 制叶片正好转到该固定位置。然后再经过时间 t2， 第一类调制叶片旋转到 同一固定位置时，再次 发信号，产生下一个连续脉冲射线束的发射周期。 该触发信号同时也发送给探测器的控制系统， 经过一定的延时， 让探测器 8开始釆集信号。 这样， 实现了各个部件之间的时间同步。
探测器可以采用多层多晶体结构的探测器。在这种情况下， 上述的加 速器可以用放射性同位素来代替。 SP， 将多种同位素组合在一起， 利用不 同的放射性同位素按照预定的时序通过准直器的狭缝而发出不同能量的 射线。 如图 4所示， 根据不同材料对相应能量的信号的釆集水平， 第一感 测部分 41可选用 Csl晶体构成，用第一感测部分 41来釆集能量稍低的射 线， 输出信号由第一输出部分 42输出。 其它能量较高的射线将穿过第一 感测部分 41， 第一输出部分 42到达滤波部分 43。 滤波部分 43是一滤波 06 003711 片， 用于实现对能量较低的射线如康普顿散射 进行滤波。 滤波部分 43 的材料可选择为 Pb或 W。第二感测部分 44可选择 CWO晶体，绝大部分 高能成分的射线在第二感测部分 44中沉淀。第二感测部分 44的信号通过 第二输出部分 45输出。 探测器得到的探测信号， 通过 ADC转换为 16位 的二进制数被传送到处理工作站 13。
得到探测值后， 利用图像处理模块对数据进行处理。首先根据已知材 料的探测结果， 标定出所有能量区间内的一组函数， 进而形成表示函数组 之间的关系的曲线。 如图 5所示， 函数组中的函数可任意选择， 例如横坐 标的值 A和纵坐标的值 P通过下式 （2 ) 和 （3 ) 来计算：
- Λ = μη X / = α χ |ΐη(/„//„0)| … （2)
Ρ =
Figure imgf000011_0001
x μη )t\ … ( 3 ) 其中下角标 、 n、 A分别代表射线的不同能量， ",Α 和 为针对已知 材料的系数， 为物体的质量厚度， 为质量衰减系数 Λ第《种能量的射 线与物体作用后的信号强度 为第 n种能量的射线与物体作用后的信号 强度。不同的函数组在不同的能量区间分辨水平不同。本发明将利用这种 特点针对不同材料使用与其相应的标定函数组来进行材料分辨。
在检査过程中将被检物体的几种能量的探测值代入标定的函数组的 函数中， 然后将得到的函数值与标定的已知材料的函数值进行比较， 初步 判断被检物体的材料可能属于的材料范围。
对于不同材料， 其最佳能量分辨区间也不同， 相应各个能量区间所选 用的函数模型也不相同。如图 6所示， 图中给出了适合区分重金属的能量 区间相应的函数关系曲线， 可以看出， 利用该能量区间的特定函数曲线， 重金属可以很好的被区分幵。因此，根据第一次判断的材料所属材料范围， 进一步利用合适的能量组合形式和相应区段的函数组，可以更准确地判断 材料属性。
当物体为质量厚度小的物体时， 会影响对材料的识别的准确性。 当所 选函数组的函数值落在坐标系的某一区域时， 或衰减很小时， 就可以认为 • 物体的质量厚度小。针对辐射与质量厚度小的物体相互作用的探测结果的 统计涨落较高的情况， 采用对应质量厚度小的物体的函数关系， 对探测值 做进一步的处理， 以保证识别的准确性。所釆用的质量厚度小的物体的函 数关系通过对实际材料的标定数据拟合而得到。
例如， 对于具有一般质量厚度的物体可使用如下式 （4) 的函数：
Figure imgf000012_0001
而对于质量厚度小的物体，这样的函数关系并不适合，此时选择如下式（5 ) 的函数：
Figure imgf000012_0002
其中 /«， 4,为射线与物体作用后的信号值； 4。,为射线与物体作用前的 信号值； 《, A y为预定系数。
图 7给出了以 6种能量为例，利用多种能量判断材料属性时的方法流 在步骤 S110, 通过 6种能量的 X射线与已知材料相互作用， 给定其 中任意三种（当然， 此处也可使用 2种或 4种等少于 6种， 不小于两种的 射线数目） 能量的某种函数关系进行函数拟和， 用以标定该材料。 这样， 可以建立各种已知材料的分类曲线。
在步骤 S120， 用具有 6种不同能量的 X射线扫描被检物体， 由探测 器采集被检物体在 6种不同能量的 X射线的扫描后的探测值。 然后， 在 步骤 S130，将 X.射线按照能量分为两组，例如将具有第一能量的 X射线、 具有第三能量的 X射线和具有第四能量的 X射线分成第一组， 而将具有 第二能量的 X射线、 具有第五能量的 X射线和具有第六能量的 X射线分 成第二组。 在步骤 S130和步骤 S140， 将每组的三种能量的探测值代入上 述标定函数中， 以初步判断材料属性。 例如通过第一组的 X射线的探测 值判断被检物体中是否包含材料 a，通过第二组的 X射线的探测值判断被 检物体中是否包含材料13。
在步骤 S150, 如果利用两组 X射线的判断结果分别是 Cu和 W， 则 分别选择更适合 Cu和 W的能量区间的探测值，利用适合该能量区段的函 数组， 进一步判断材料属性。 例如， 对于上述的材料 ， 利用适合其最佳 分辨率的能量范围中的射线束， 例如具有第二能量的 X射线、 具有第三 能量的 X射线和具有第四能量的 X射线， 的探测值的给定函数组来进一 步判断材料 a的材料属性。 对于上述的材料 b， 利用适合其最佳分辨率的 能量范围中的射线束， 例如具有第四能量的 X射线、 具有第五能量的 X 射线和具有第六能量的 X射线， 的探测值的给定函数组来进一步判断材 料 b的材料属性。 '
进一步的判断可以得到 Cu和 W中有一种是不符合相应的函数关系的 判断结果。 显然， 继续增多能量， 可以使得区段分得更为细致， 通过对比 能够看出，通过多能量进行能量区段选择方法可以很大程度的提高材料属 性判断的准确性。
最后， 为了得到清晰的被检物体图像， 可以对能量不同的 X射线扫描 被检物体后得到的多幅图像进行融合处理， 得到质量更佳的扫描图像。
众所周知， 高能射线对物体的穿透力强， 对质量厚度大的物体穿透后 得到的探测数据精确度较高，所以对质量厚度大的灰度图像较清晰。但在， 高能射线在分辨较薄质量厚度时将得到比较模糊的灰度图像，容易丢失细 节信息。而这缺点刚好是低能量的射线穿透材料后得到的灰度图像能弥补 的。 '
图 8是利用不同质量厚度信息调整图像的方法流程图。 该图像融合过 程利用高低能射线对物体不同质量厚度的不同衰减特性，通过两种探测值 的融合得到在较宽质量厚度范围内清晰的图像。
在步骤 S210和 S220，确定被检物体的材料属性，例如被检物体的质量 厚度是厚的还是薄的。这里， 根据射线的衰减情况， 判断物体的质量厚度 的大致范围， 即当衰减很严重时， 例如小于预定的阈值， 认为是高质量厚 度的物体，衰减很少时，例如大于预定的阈值，认为是低质量厚度的物体。
在步骤 S230,对于质量厚度小的物体， 给高能数据赋予较小的权重因 子， 如 30 % ; 对低能量数据赋予较大的权重因子， 如 70%。
在步骤 S240,对于质量厚度大的物体，给高能数据赋予较大的权重因 子， 如 70% ; 对低能数据赋予较小的权重因子， 如 30 %。
然后， 在步骤 S250, 按照上述赋予的权重因子， 合成高能图像和低能 与具相对应的预先确定好的阈值作比较，给高能量和低能量的数据分别赋 予不同的权重因子， 从而合成得到最终图像的灰度信息。
虽然， 射线对不同质量厚度的物体相互作用后， 探测得到的图像有着 不同的图像特性， 但是通过上述方法处理后， 在检测扫描物体的过程中， 对各个部分的质量厚度相差比较大的物体，同样可以得到很清晰的灰度图 '像。
如上所述， 由加速器产生不少于 3束不同能量的 X射线， 它们分别与 同一物体作用， 探测器探测穿透物体后射线， 然后通过对探测结果的分析 处理， 实现对被检物体材料属性的区分。
加速器通过改变加速器的工作参数，可以产生多束不同能量比例占优 的 X射线能谱。 由于加速器产生的 X射线能量其能谱范围比较宽， 其他能 量的 X射线所占的比例比较大， 这将影响材料识别的准确度， 因此需要通 过能谱调制的方法提高 X射线谱中所需能量的 X射线的比例。 针对不同能 量的 X射线， 利用不同的材料进行调制， 得到优化后的 X射线能谱。 当然， 利用不伺的放射性元素作为不同能量的放射源可以不需要进行能谱调制， 但可选择的能量范围不是连续的。
如前所述， 由于直接由加速器产生的 X射线是一连续谱， 这将影响材 料的分辨的正确率。 本发明将釆用了能谱调制器对加速器产生的 X射线进 行能谱调制。 不同的能量， 采用不同的材料进行能谱调制， 从而得到最适 合材料分辨的能谱。
X射线能谱分布能量范围不同，所适合的能谱调制材料也不同。例如： 当某一束 X射线能谱分布的主要能量范围下限高于某一能量较高的阈值 (如〜 3MeV) 时， 应该选择低 Z材料作为该束 X射线的能谱调制材料， 如 B、 聚乙烯及其他富氢有机材料等。 同时， 为了吸收射线中能量较低的散 射成分， 最好同时在较厚的低 Z材料进行能谱调制后， 再添加较薄的高 Z 材料进行能谱调制。 当某一束 X射线能谱分布的主要能量范围下限高于某 一能量较低的阈值 （如〜 300keV) 时， 应该选择高 Z材料作为该束 X射线 的能谱调制材料， 如 Pb、 W、 U等， 但也可以选择中 Z材料如 Cu。
在探测过程中， 采用分层的探测器来探测多束能量不同的 X射线， 以 精确的得到各种能量的射线与物体作用后的信号值，从而能准确的区分各 柙能重的射线与物体作用的区别。 不同的探测晶体， 对不同的能量的 X射 线敏感， 表现出不同的响应特性。让不同能量的射线在不同的探测晶体里 产生信号并采集， 同时对各种能量的探测信号采用综合处理的方法，进一 步的利用各种能量的信号。
由于不同的材料与射线作用的差别最明显的射线能量范围是不同的。 因此， 对于不同的材料， 要想能准确的得到材料的材料属性， 应使用有利 于区分材料分辨的特定能量范围，预先给出该能量范围的最低阈值和最高 能量阈值。 例如， 最适合区分有机物和无机物的能量区间为： 0.3MeV〜 3MeV和最适合区分重金属的能量区间为： lMeV〜4MeV， 相应于不同的 能量区间， 所使用的处理函数也不相同。
如上所述， 利用不同能量的 X射线实现对材料属性的分辨， 其关键 之处是要能够精确的探测到不同能量的 X射线与物体相互作用时的区别。 另外， 在上述操作中， 对物体的质量厚度进行分析。 由于所选探测能量通 常会高于某个值， 决定了相应的 不可能太小， 因此可以根据函数值所处 坐标系的区域判断物体的质量厚度。 当被检物体的质量厚度比较小的时 候， 辐射物理中固有的统计性变得不可忽视。对于加速器产生的连续能谱 的 X射线， 其占优的能量段的射线与物体作用的特性将不容易表现出来。 这导致对探测精度的下降， 对材料属性的分辨正确率降低。 因此， 针对被 检物体质量厚度较薄的情况， 选择对物体作用最为敏感的能量区间， 并利 用针对高涨落情况设定的处理模型对探测值进行相应的处理，最终准确的 得到被检物体的材料属性。
. 另外， 本发明还可以有各种变型， 例如， 可以釆甩 X光机来代替上 述的加速器。 在这种情况下， 需要在 X光机的射线输出端配置本发明的 能谱调制器。

Claims

权 利 要 求
1、 .一种利用具有多种能量的辐射检査物体的方法， 包括步骤： 利用具有多种能量的辐射与被检物体相互作用；
探测并记录具有不同能量的辐射与被检物体相互作用后的探测值； 通过将探测值的一部分代入预定的标定函数中，来获取包括物体的初 步材料属性的信息；
在与所述信息相对应的能量区间利用适合该能量区间的函数组，判断 物体的进一步材料属性。
2、 如权利要求 1所述的方法， 其特征在于， 所述信息还包括物体的 质量厚度信息。
3、 如权利要求 1或 2所述的方法， 其特征在于， 所述的标定函数是 在具有不同能量的辐射与已知材料相互作用后探测的值的拟合函数。
4、 如权利要求' 3所述的方法， 其特征在于， 用于拟合标定函数的与 已知材料相互作用的辐射束的数目不小于与被检物体相互作用的辐射束 的数目。
5、 如权利要求 1所述的方法， 其特征在于， 所述的多种能量至少为 3种不同的能量或能谱。
6、 如权利要求 3所述的方法， 其特征在于， 所述的多种能量至少为 3种不同的能量或能谱。
7、 如权利要求 1所述的方法， 其特征在于， 所述的与物体相互作用 后的探测值为辐射穿透物体后的透射强度值。
8、 如权利要求 3所述的方法， 其特征在于， 所述的与物体相互作用 后的探测值为辐射穿透物体后的透射强度值。
9、 如权利要求 1所述的方法， 其特征在于， 所述的能量区间， 是指 该能量区间的辐射与一材料相互作用后的探测值的函数值与其他材料探 测值的函数值的差别相比于其它区间更大的区间。
10、 如权利要求 1所述的方法， 其特征在于， 所述函数组， 在一能量 区间内可令不同材料的探测值间的细小差别变得明显，同时能够降低无差 别部分的影响。
11、 如权利要求 1所述的方法， 其特征在于， 所述函数组， 是指对应 厚度不同的材料， 使用不同的函数处理模型分段处理。
12、 如权利要求 1所述的方法， 其特征在于， 所述的辐射的辐射源为 放射性同位素。
13、 如权利要求 1所述的方法， 其特征在于， 所述的辐射的辐射源为 加速器。
14、 如权利要求 1所述的方法， 其特征在于， 所述的辐射的辐射源为 X光机。
15、 一种利用具有多种能量的辐射检查物体的方法， 包括： 利用具有多种能量的辐射与被检物体相互作用；
探测具有不同能量的辐射与被检物体相互作用后的探测值，以形成与 不同能量的辐射相对应的图像；
将一部分探测值代入预定的标定函数中， 以判断物体的质量厚度； 根据质量厚度， 选择不同能量探测值的权重， 对图像进行融合处理， 得到更准确的灰度图像。
16、 如权利要求 15所述的方法， 其特征在于， 所述方法还包括步骤: 将所述灰度图像的灰度等级转换到彩色图像中相对应的色彩级别。
17、 如权利要求 15或 16所述的方法， 其特征在于， 所述的多种能量 至少为 2种不同的能量。
18、如权利要求 15或 16所述的方法， 其特征在于， 所述对物体的质 量厚度的判断， 是根据辐射的实际衰减情况进行判断的。 '
19、 如权利要求 15或 16所述的方法， 其特征在于， 所述选择不同能 量探测值的权重， 是指对于越薄的材料， 高能辐射探测值所占权重越小， 低能辐射探测值所占权重越大； 对于越厚的材料，低能辐射探测值所占权 重越小， 高能辐射探测值所占权重越大。
20、 一种用于实施权利要求 1或 15所述的利用具有多种能量的辐射 检查物体的方法的设备， 包括：
一组可产生多种具有不同能量的辐射的辐射源；
一种适合同时探测多种具有不同能量的辐射的探测器模块阵列； 一个与探测器模块阵列相连的处理器，用于对具有不同能量的辐射与 物体相互作用后的探测值进行处理， 得到物体的材料属性和 /或产生物体 的灰度图像；
一个控制系统， 与所述的辐射源连接， 用于按照预定的时序改变辐射 源的工作参数。
21、 如权利要求 20所述的设备， 其特征在于， 所述的多种不同能量 至少为 3种不同的能量或能谱。
22、 如权利要求 20所述的设备， 其特征在于， 所述的多种不同能量 至少为 2种不同的能量或能谱。
23、 如权利要求 20、 21或 22所述的设备， 其特征在于， 所述探测器 阵列为多层多晶体探测器， 由不同晶体复合而成。
24、 如权利要求 23所述的设备， 其特征在于， 所述探测器阵列中， 不同晶体之间有滤波片隔开。
25、 如权利要求 20、 21或 22所述的设备， 其特征在于， 所述辐射源 为放射性同位素。
26、 如权利要求 25所述的设备， 其特征在于， 所述的辐射源是一种 不同元素的放射性同位素的组合，利用不同的放射性同位素按时序轮流通 过准直器的狭缝而发出不同能量的辐射。
27、 如权利要求 20、 21或 22所述的设备， 其特征在于， 所述辐射源 是一种可发射出不同能量占优的连续能谱辐射的加速器。
28、 如权利要求 27所述的设备， 其特征在于， 所述加速器包括一个 置于辐射出口前端的用于能谱调制的能谱调制器。
29、 如权利要求 20、 21或 22所述的设备， 其特征在于， 所述辐射源 为 X光机。
30、 如权利要求 29所述的设备， 其特征在于， 所述 X光机包括一个 置于辐射出口前端的用于能谱调制的能谱调制器。
31、 如权利要求 28所述的设备， 其特征在于， 所述能谱调制器呈轮 盘状， 由不同调制材料构成叶片， 叶片按与相应能量辐射束相对应的时序 围绕轴旋转。
32、 如权利要求 30所述的设备， 其特征在于， 所述能谱调制器呈轮 盘状， 由不同调制材料构成叶片， 叶片按与相应能量辐射束相对应的时序 围绕轴旋转。
33、 如权利要求 28所述的设备， 其特征在于， 所述能谱调制器通过 发射触发信号到辐射源的控制系统以及发射釆集信号到探测器的控制器 使辐射源出束与探测器采集信号同步进行。
34、 如权利要求 33所述的设备.， 其特征在于， 所述能谱调制器呈轮 盘状， 由不同调制材料构成叶片， 叶片按与相应能量辐射束相对应的时序 围绕轴旋转。
35、 如权利要求 20所述的设备， 其特征在于， 所述控制系统接收到 触发信号时， 将立即给辐射源发送各种不同能量对应的信号， 让辐射源工 作在所需的工作状态下。
36、 如权利要求 20、 21或 22所述的设备， 其特征在于， 所述的各种 能量的探测值为辐射穿透物体后的透射强度值。
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8837669B2 (en) 2003-04-25 2014-09-16 Rapiscan Systems, Inc. X-ray scanning system
US8885794B2 (en) 2003-04-25 2014-11-11 Rapiscan Systems, Inc. X-ray tomographic inspection system for the identification of specific target items
US8958526B2 (en) 2005-12-16 2015-02-17 Rapiscan Systems, Inc. Data collection, processing and storage systems for X-ray tomographic images
US9020095B2 (en) 2003-04-25 2015-04-28 Rapiscan Systems, Inc. X-ray scanners
US9048061B2 (en) 2005-12-16 2015-06-02 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US9113839B2 (en) 2003-04-25 2015-08-25 Rapiscon Systems, Inc. X-ray inspection system and method

Families Citing this family (79)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7963695B2 (en) 2002-07-23 2011-06-21 Rapiscan Systems, Inc. Rotatable boom cargo scanning system
US8275091B2 (en) 2002-07-23 2012-09-25 Rapiscan Systems, Inc. Compact mobile cargo scanning system
US8223919B2 (en) 2003-04-25 2012-07-17 Rapiscan Systems, Inc. X-ray tomographic inspection systems for the identification of specific target items
GB0309379D0 (en) 2003-04-25 2003-06-04 Cxr Ltd X-ray scanning
US8804899B2 (en) 2003-04-25 2014-08-12 Rapiscan Systems, Inc. Imaging, data acquisition, data transmission, and data distribution methods and systems for high data rate tomographic X-ray scanners
GB0309385D0 (en) * 2003-04-25 2003-06-04 Cxr Ltd X-ray monitoring
US6928141B2 (en) 2003-06-20 2005-08-09 Rapiscan, Inc. Relocatable X-ray imaging system and method for inspecting commercial vehicles and cargo containers
US7471764B2 (en) 2005-04-15 2008-12-30 Rapiscan Security Products, Inc. X-ray imaging system having improved weather resistance
DE102005020567A1 (de) * 2005-04-30 2006-11-09 Katz, Elisabeth Verfahren und Vorrichtung zur Online-Bestimmung des Aschegehalts einer auf einem Födermittel geförderten Substanz und Vorrichtung zur Durchführung einer Online-Analyse
WO2008142446A2 (en) * 2007-05-17 2008-11-27 Durham Scientific Crystals Ltd Energy dispersive x-ray absorption spectroscopy in scanning transmission mode involving the calculation of the intensity ratios between successive frequency bands
CN101358936B (zh) 2007-08-02 2011-03-16 同方威视技术股份有限公司 一种利用双视角多能量透射图像进行材料识别的方法及系统
FR2919780B1 (fr) 2007-08-02 2017-09-08 Nuctech Co Ltd Procede et systeme d'identification de matiere a l'aide d'images binoculaires stereoscopiques et par transmission multi-energie
DE102007042144A1 (de) * 2007-09-05 2009-03-12 Smiths Heimann Gmbh Verfahren zur Verbesserung der Materialerkennbarkeit in einer Röntgenprüfanlage und Röntgenprüfanlage
CN101435783B (zh) * 2007-11-15 2011-01-26 同方威视技术股份有限公司 物质识别方法和设备
GB0803644D0 (en) 2008-02-28 2008-04-02 Rapiscan Security Products Inc Scanning systems
GB0803641D0 (en) 2008-02-28 2008-04-02 Rapiscan Security Products Inc Scanning systems
CN101571595B (zh) * 2008-04-28 2012-04-18 同方威视技术股份有限公司 放射性物质探测与识别设备及其方法
WO2009137698A1 (en) 2008-05-08 2009-11-12 Mcnabb Ronald Steven Jr Adaptive scanning in an imaging system
GB0809110D0 (en) 2008-05-20 2008-06-25 Rapiscan Security Products Inc Gantry scanner systems
US8401270B2 (en) * 2008-06-13 2013-03-19 L-3 Communications Security And Detection Systems, Inc. Examination of a region using dual-energy radiation
CN101614683B (zh) * 2008-06-27 2011-10-05 清华大学 物质识别系统中的实时标定设备和方法
UA89318C2 (ru) 2008-08-12 2010-01-11 Институт Сцинтилляционных Материалов Нан Украины Рентгенографический способ распознавания материалов и устройство для его осуществления
CN102203637B (zh) * 2008-08-27 2015-05-06 洛斯阿拉莫斯国家安全股份有限公司 基于宇宙射线产生的带电粒子的成像
US7991117B2 (en) * 2009-01-13 2011-08-02 Varian Medical Systems, Inc. Apparatus and method to facilitate dynamically adjusting radiation intensity for imaging purposes
US8232748B2 (en) * 2009-01-26 2012-07-31 Accuray, Inc. Traveling wave linear accelerator comprising a frequency controller for interleaved multi-energy operation
US8218731B2 (en) * 2009-05-22 2012-07-10 L-3 Communication Security and Detection Systems, Inc. Filtering of a source of pulsed radiation
US8184769B2 (en) * 2009-06-05 2012-05-22 Varian Medical Systems, Inc. Method and apparatus to facilitate using multiple radiation-detection views to differentiate one material from another
US8422826B2 (en) * 2009-06-05 2013-04-16 Varian Medical Systems, Inc. Method and apparatus to facilitate using fused images to identify materials
CN101937729B (zh) * 2009-06-30 2012-12-12 同方威视技术股份有限公司 电子束辐照加工的方法和装置
US8203289B2 (en) * 2009-07-08 2012-06-19 Accuray, Inc. Interleaving multi-energy x-ray energy operation of a standing wave linear accelerator using electronic switches
FR2953603A1 (fr) 2009-12-09 2011-06-10 Commissariat Energie Atomique Procede et dispositif de reconnaissance d'un materiau a l'aide de sa fonction de transmission
US8311187B2 (en) 2010-01-29 2012-11-13 Accuray, Inc. Magnetron powered linear accelerator for interleaved multi-energy operation
US8284898B2 (en) * 2010-03-05 2012-10-09 Accuray, Inc. Interleaving multi-energy X-ray energy operation of a standing wave linear accelerator
US8836250B2 (en) 2010-10-01 2014-09-16 Accuray Incorporated Systems and methods for cargo scanning and radiotherapy using a traveling wave linear accelerator based x-ray source using current to modulate pulse-to-pulse dosage
US9258876B2 (en) 2010-10-01 2016-02-09 Accuray, Inc. Traveling wave linear accelerator based x-ray source using pulse width to modulate pulse-to-pulse dosage
US8942351B2 (en) 2010-10-01 2015-01-27 Accuray Incorporated Systems and methods for cargo scanning and radiotherapy using a traveling wave linear accelerator based X-ray source using pulse width to modulate pulse-to-pulse dosage
US9167681B2 (en) 2010-10-01 2015-10-20 Accuray, Inc. Traveling wave linear accelerator based x-ray source using current to modulate pulse-to-pulse dosage
CN102455305B (zh) * 2010-11-01 2014-06-18 北京中盾安民分析技术有限公司 双能量x射线人体藏物检查设备中所使用的图像处理方法
CN102053096B (zh) * 2010-11-04 2013-02-13 公安部第一研究所 双能量x射线安全检查设备的材料校准系统及校准方法
JP5651007B2 (ja) * 2010-12-28 2015-01-07 アンリツ産機システム株式会社 Ｘ線検査装置
JP5771013B2 (ja) * 2011-01-25 2015-08-26 アンリツ産機システム株式会社 Ｘ線異物検出装置
US9218933B2 (en) 2011-06-09 2015-12-22 Rapidscan Systems, Inc. Low-dose radiographic imaging system
KR101460616B1 (ko) * 2011-08-31 2014-11-14 삼성전자주식회사 멀티 에너지 방사선 데이터를 이용한 방사선 영상 생성 방법 및 장치
US9970890B2 (en) * 2011-10-20 2018-05-15 Varex Imaging Corporation Method and apparatus pertaining to non-invasive identification of materials
CN102662189B (zh) * 2012-04-13 2013-11-27 北京华泰诺安科技有限公司 一种基于计数管的辐射测试的分析方法
RU2598396C2 (ru) * 2012-07-26 2016-09-27 Университет Цинхуа Метод и система комбинированного радиационного неразрушающего контроля
DE102012215515A1 (de) * 2012-08-31 2014-03-06 Klinikum Der Universität München Verfahren zur Detektion von Schäden an Silikonimplantaten und Computertomographiegerät
US8983234B2 (en) 2012-09-28 2015-03-17 Varian Medical Systems, Inc. Method and apparatus pertaining to using imaging information to identify a spectrum
RU2015123316A (ru) * 2013-01-04 2017-02-09 Американ Сайенс Энд Инжиниринг, Инк. Динамическое уменьшение дозы при обследовании с помощью рентгеновских лучей
US9791590B2 (en) 2013-01-31 2017-10-17 Rapiscan Systems, Inc. Portable security inspection system
US9778391B2 (en) * 2013-03-15 2017-10-03 Varex Imaging Corporation Systems and methods for multi-view imaging and tomography
BR112015030155B8 (pt) 2013-11-14 2019-09-24 Nuctech Co Ltd acelerador de múltiplas dosagens e múltiplas alimentações, método para inspecionar áreas diferentes usando um acelerador, e, sistema de detecção de raios
CN104749199B (zh) 2013-12-30 2019-02-19 同方威视技术股份有限公司 双能/双视角的高能x射线透视成像系统
US10459111B2 (en) * 2014-05-23 2019-10-29 Radiabeam Technologies, Llc System and method for adaptive X-ray cargo inspection
CN105242322A (zh) * 2014-06-25 2016-01-13 清华大学 探测器装置、双能ct系统和使用该系统的检测方法
CN104374785B (zh) * 2014-11-14 2017-12-05 北京君和信达科技有限公司 一种连续通过式辐射扫描系统和方法
PL3078944T3 (pl) * 2015-04-07 2020-08-10 Mettler-Toledo, LLC Sposób ustalania masy obiektów na podstawie wielu obrazów rentgenowskich wykonanych na różnych poziomach energii
CN106353828B (zh) * 2015-07-22 2018-09-21 清华大学 在安检系统中估算被检查物体重量的方法和装置
CA2998364A1 (en) 2015-09-10 2017-03-16 American Science And Engineering, Inc. Backscatter characterization using interlinearly adaptive electromagnetic x-ray scanning
CN105181723B (zh) * 2015-09-28 2019-02-12 同方威视技术股份有限公司 双能射线扫描系统、扫描方法以及检查系统
JP2017122705A (ja) * 2016-01-06 2017-07-13 三菱電機株式会社 算出方法、判定方法、選別方法および選別装置
CN106841248B (zh) * 2017-04-07 2023-10-31 北京华力兴科技发展有限责任公司 车辆或集装箱的安全检查系统
FR3067461B1 (fr) * 2017-06-07 2023-02-24 Multix Sa Procede de determination de proprietes physiques d'un echantillon
EP3494889B1 (de) * 2017-12-11 2020-06-17 Siemens Healthcare GmbH Verfahren zur kalibrierung einer röntgenmesseinrichtung
KR102075466B1 (ko) * 2018-01-29 2020-02-10 한국원자력연구원 방사선원 시스템 및 이를 구비하는 비파괴 검사 시스템
US10705243B2 (en) * 2018-01-29 2020-07-07 Korea Atomic Energy Research Institute Nondestructive inspection system
WO2019177799A1 (en) * 2018-03-16 2019-09-19 Oregon State University Apparatus and process for optimizing radiation detection counting times using machine learning
US11047813B2 (en) 2018-05-21 2021-06-29 Volodymyr Pavlovich ROMBAKH Non-invasive monitoring of atomic reactions to detect structural failure
GB2577737B (en) * 2018-10-05 2022-09-07 Smiths Heimann Sas Determination of material
KR102609389B1 (ko) * 2019-01-30 2023-12-01 노드슨 코포레이션 복사선-기반의 두께 게이지
CN112146601B (zh) * 2019-06-27 2021-07-16 清华大学 基于剂量场检测的辐射成像方法及装置
CN110231005B (zh) * 2019-06-27 2021-04-13 江苏同威信达技术有限公司 一种物品质量厚度检测方法及物品质量厚度检测装置
WO2020259368A1 (zh) 2019-06-27 2020-12-30 清华大学 物品剂量分布检测方法及装置
CN113116366A (zh) * 2020-01-10 2021-07-16 北京友通上昊科技有限公司 多能x射线成像方法、存储介质、x射线源及成像系统
US11193898B1 (en) 2020-06-01 2021-12-07 American Science And Engineering, Inc. Systems and methods for controlling image contrast in an X-ray system
CN112067638A (zh) * 2020-08-11 2020-12-11 许昌瑞示电子科技有限公司 一种物质分类系统和用于物质分类的射线能谱测定探测器
WO2022180776A1 (ja) * 2021-02-26 2022-09-01 株式会社日立製作所 材料識別支援装置、方法およびプログラム
CN113238298B (zh) * 2021-07-09 2022-03-04 同方威视技术股份有限公司 检查系统及方法
WO2024026152A1 (en) * 2022-07-26 2024-02-01 Rapiscan Holdings, Inc. Methods and systems for performing on-the-fly automatic calibration adjustments of x-ray inspection systems

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1132856A (zh) * 1994-11-23 1996-10-09 唐志宏 X射线(或γ射线)无损检查系统
US6018562A (en) * 1995-11-13 2000-01-25 The United States Of America As Represented By The Secretary Of The Army Apparatus and method for automatic recognition of concealed objects using multiple energy computed tomography
US6069936A (en) * 1997-08-18 2000-05-30 Eg&G Astrophysics Material discrimination using single-energy x-ray imaging system
US20050025280A1 (en) * 2002-12-10 2005-02-03 Robert Schulte Volumetric 3D x-ray imaging system for baggage inspection including the detection of explosives
WO2005059594A1 (en) * 2003-12-16 2005-06-30 Soreq Nuclear Research Center Method and system for detecting substances, such as special nuclear materials
US20050276376A1 (en) * 2004-05-27 2005-12-15 L-3 Communications Security And Detection Systems, Inc. Contraband detection systems using a large-angle cone beam CT system

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE58903297D1 (de) * 1989-04-06 1993-02-25 Heimann Systems Gmbh & Co Materialpruefanlage.
JPH0375583A (ja) * 1989-08-17 1991-03-29 Mitsubishi Electric Corp 放射線検出装置
GB9200828D0 (en) * 1992-01-15 1992-03-11 Image Research Ltd Improvements in and relating to material identification using x-rays
FR2708751B1 (fr) * 1993-07-30 1995-10-06 Schlumberger Ind Sa Procédé et dispositif pour détecter la présence d'un objet, comportant un matériau donné, non accessible à la vue.
BR9506680A (pt) 1994-02-03 1997-09-09 Analogic Corp Disposiçao modular para um conjunto de detectores de raios-x e disposiçao modular para um conjunto de detectores de raios-x sustentando uma fonte de raios-x oposta em um disco rotativo de um sistema tomográfico
JPH08178873A (ja) * 1994-12-21 1996-07-12 Tokyo Metropolis マルチエネルギー放射線透過試験方法
EP0873511A1 (en) * 1995-11-13 1998-10-28 The United States of America as represented by The Secretary of the Army Apparatus and method for automatic recognition of concealed objects using multiple energy computed tomography
JPH10104175A (ja) * 1996-10-01 1998-04-24 Shimadzu Corp 材質特定ｘ線検査装置
JPH11230918A (ja) * 1998-02-12 1999-08-27 Hitachi Medical Corp Ｘ線検査装置
JP2001099790A (ja) * 1999-09-30 2001-04-13 Ishikawajima Harima Heavy Ind Co Ltd Ｘ線検査装置
JP2003279503A (ja) * 2002-03-22 2003-10-02 Shimadzu Corp Ｘ線検査装置
WO2004030162A2 (en) 2002-09-27 2004-04-08 Scantech Holdings, Llc System for alternately pulsing energy of accelerated electrons bombarding a conversion target
WO2005084352A2 (en) 2004-03-01 2005-09-15 Varian Medical Systems Technologies, Inc. Dual energy radiation scanning of objects
GB0512945D0 (en) * 2005-06-24 2005-08-03 Oxford Instr Analytical Ltd Method and apparatus for material identification
CN101074937B (zh) * 2006-05-19 2010-09-08 清华大学 能谱调制装置、识别材料的方法和设备及图像处理方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1132856A (zh) * 1994-11-23 1996-10-09 唐志宏 X射线(或γ射线)无损检查系统
US6018562A (en) * 1995-11-13 2000-01-25 The United States Of America As Represented By The Secretary Of The Army Apparatus and method for automatic recognition of concealed objects using multiple energy computed tomography
US6069936A (en) * 1997-08-18 2000-05-30 Eg&G Astrophysics Material discrimination using single-energy x-ray imaging system
US20050025280A1 (en) * 2002-12-10 2005-02-03 Robert Schulte Volumetric 3D x-ray imaging system for baggage inspection including the detection of explosives
WO2005059594A1 (en) * 2003-12-16 2005-06-30 Soreq Nuclear Research Center Method and system for detecting substances, such as special nuclear materials
US20050276376A1 (en) * 2004-05-27 2005-12-15 L-3 Communications Security And Detection Systems, Inc. Contraband detection systems using a large-angle cone beam CT system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9442082B2 (en) 2003-04-25 2016-09-13 Rapiscan Systems, Inc. X-ray inspection system and method
US10175381B2 (en) 2003-04-25 2019-01-08 Rapiscan Systems, Inc. X-ray scanners having source points with less than a predefined variation in brightness
US11796711B2 (en) 2003-04-25 2023-10-24 Rapiscan Systems, Inc. Modular CT scanning system
US9020095B2 (en) 2003-04-25 2015-04-28 Rapiscan Systems, Inc. X-ray scanners
US9618648B2 (en) 2003-04-25 2017-04-11 Rapiscan Systems, Inc. X-ray scanners
US9113839B2 (en) 2003-04-25 2015-08-25 Rapiscon Systems, Inc. X-ray inspection system and method
US8885794B2 (en) 2003-04-25 2014-11-11 Rapiscan Systems, Inc. X-ray tomographic inspection system for the identification of specific target items
US10901112B2 (en) 2003-04-25 2021-01-26 Rapiscan Systems, Inc. X-ray scanning system with stationary x-ray sources
US8837669B2 (en) 2003-04-25 2014-09-16 Rapiscan Systems, Inc. X-ray scanning system
US9675306B2 (en) 2003-04-25 2017-06-13 Rapiscan Systems, Inc. X-ray scanning system
US9048061B2 (en) 2005-12-16 2015-06-02 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US10295483B2 (en) 2005-12-16 2019-05-21 Rapiscan Systems, Inc. Data collection, processing and storage systems for X-ray tomographic images
US9638646B2 (en) 2005-12-16 2017-05-02 Rapiscan Systems, Inc. X-ray scanners and X-ray sources therefor
US10976271B2 (en) 2005-12-16 2021-04-13 Rapiscan Systems, Inc. Stationary tomographic X-ray imaging systems for automatically sorting objects based on generated tomographic images
US8958526B2 (en) 2005-12-16 2015-02-17 Rapiscan Systems, Inc. Data collection, processing and storage systems for X-ray tomographic images

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US7580505B2 (en) 2009-08-25
AU2006252235B2 (en) 2008-09-25
US20070183568A1 (en) 2007-08-09
GB0625825D0 (en) 2007-02-07
CN1995993A (zh) 2007-07-11
GB2433777A (en) 2007-07-04
RU2351921C2 (ru) 2009-04-10
JP4744428B2 (ja) 2011-08-10
AU2006252235A1 (en) 2007-07-19
KR100862347B1 (ko) 2008-10-13
RU2006146969A (ru) 2008-12-27
DE102006062009A1 (de) 2007-09-06
GB2433777B (en) 2008-11-05
CN1995993B (zh) 2010-07-14
KR20070072422A (ko) 2007-07-04
JP2007183277A (ja) 2007-07-19
HK1109656A1 (en) 2008-06-13

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