KR20180079970A - Container inspection system - Google Patents

Abstract

The present invention relates to a system for inspecting a container by acquiring a radioscopic image of the container while a radiation source moves when the container is fixed. The system includes: a moving frame (100) moving along an inspection section; a linear accelerator (200) installed in the moving frame to generate radiation; a radiation irradiation unit (300) installed in the moving frame to irradiate the radiation generated by the linear accelerator to an inspection target object; a radiation detection unit (400) installed in the moving frame while facing the radiation irradiation unit to detect penetrating radiation of the inspection target object; and an image output unit (500) for making an image of a radiation signal detected by the radiation detection unit (130) and outputting the image of the radiation signal.

Description

CONTAINER INSPECTION SYSTEM

The present invention relates to a system in which a container is retrieved by acquiring a radiographic image of a container while moving the radiation source while the container is stationary.

Import and export cargoes are subjected to a certain inspection procedure before or after unloading the containers to detect trafficking goods and various agricultural and marine products. In general, the manual inspection process for one container takes 4 to 5 hours.

In order to shorten the inspection time of containers requiring long time, there is a container search system using radiation. Such a search system irradiates X-rays to a container in a state of being loaded on a vehicle without opening the container, Inspection is performed using the perspective image of the container obtained by detecting the intensity of the line and imaging it.

Generally, a linear accelerator is used as a radiation source for generating X-rays in a container search system. An electron beam is accelerated by using a linear accelerator, and an accelerated electron beam is irradiated onto a target (Cu or W) . On the other hand, linear accelerators used for accelerating electron beams in a general container search system use L-band (about 1.5 GHz) or S-band (about 3 GHz) linear accelerators depending on the resonance frequency range used for electron beam acceleration, Band linear accelerators are fixed to the ground with only a few meters in length of the accelerating tube itself and corresponding weight.

Therefore, in the conventional container search system, the inspection target vehicle is moved while the radiation source is fixed on the ground. At this time, the inspection target vehicle is not driven by the driver but is moved by the unmanned traction device, The worker is prevented from being directly exposed to X-rays having high permeability.

Regarding this, in Registration Practical Utility Model No. 20-0403672 (Publication Date: Dec. 13, 2005) and Patent Document 10-2016-0139880 (Publication Date: Dec. 20, 2017), a container car A system for automatic movement to the unmanned state is proposed.

Thus, in the conventional container search system, the source of the radiation source is fixed on the ground, and a moving facility for moving the inspection target vehicle to the unmanned state is required. In addition, in order to secure the movement path of the inspection target vehicle and the inspection waiting vehicles A wide installation area and many additional facilities are required.

Registration Utility Model Bulletin No. 20-0403672 (Publication Date: December 13, 2005)

Japanese Patent Application Laid-Open No. 10-2016-0139880 (Publication date: 2016.12.07)

Accordingly, it is an object of the present invention to provide a system capable of searching a container by acquiring a radioscopic image of a container while a radiation source moves while a container is fixedly positioned.

To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a container search system comprising: a mobile frame capable of moving along a search interval; A linear accelerator installed in the moving frame for generating radiation; A radiation irradiator installed in the moving frame for irradiating the object to be examined with radiation generated in the linear accelerator; A radiation detecting unit installed on the moving frame so as to face the radiation applying unit and detecting transmitted radiation of a search target; And an image output unit for imaging and outputting the radiation signal detected by the radiation detecting unit.

Preferably, the linear accelerator accelerates the electron beam by a resonance frequency of X-band (8 to 12 GHz) to generate radiation.

Preferably, the linear accelerator includes an acceleration tube for accelerating electrons in a standing wave mode by an RF signal applied at an X-band resonance frequency; An electron gun for generating electrons in the acceleration tube; An electron gun driving unit for supplying driving power to the electron gun; An RF generator for generating an RF signal in the acceleration tube; And a pulse modulator for generating a high-voltage DC pulse for operating the electron gun and the RF generator.

More preferably, the control unit further comprises a control unit for controlling the output energy of the electron beam output from the acceleration tube by controlling the output of the pulse modulator, more preferably, the image output unit outputs And outputs the respective perspective images for the radiation of energy.

Preferably, the moving frame includes a first moving part in which the linear accelerator and the irradiation part are housed and movable; A second moving unit disposed in parallel with the first moving unit and capable of receiving and moving the radiation detecting unit; And a horizontal fixing unit connecting and fixing the first moving unit and the second moving unit.

The container search system according to the present invention uses a small and lightweight linear accelerator capable of accelerating an electron beam by an X-band (8 to 12 GHz) resonance frequency to generate radiation, It is possible to acquire a perspective image, thereby reducing the size of the container search system and the search time compared with the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a container search system according to the present invention; FIG.
3 is a configuration diagram of a linear accelerator according to a preferred embodiment of the present invention,
FIG. 4 is a cross-sectional view of an X-band linear acceleration tube according to a preferred embodiment of the present invention;
5 is a view for explaining a container search system according to another embodiment of the present invention.

The specific structure or functional description presented in the embodiment of the present invention is merely illustrative for the purpose of illustrating an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention can be implemented in various forms. And should not be construed as limited to the embodiments described herein, but should be understood to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Meanwhile, in the present invention, the terms first and / or second etc. may be used to describe various components, but the components are not limited to the terms. The terms may be referred to as a second element only for the purpose of distinguishing one element from another, for example, to the extent that it does not depart from the scope of the invention in accordance with the concept of the present invention, Similarly, the second component may also be referred to as the first component.

Whenever an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but it should be understood that other elements may be present in between something to do. On the other hand, when it is mentioned that an element is "directly connected" or "directly contacted" to another element, it should be understood that there are no other elements in between. Other expressions for describing the relationship between components, such as "between" and "between" or "adjacent to" and "directly adjacent to" should also be interpreted.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It will be further understood that the terms " comprises ", or "having ", and the like in the specification are intended to specify the presence of stated features, integers, But do not preclude the presence or addition of steps, operations, elements, parts, or combinations thereof.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Meanwhile, in the embodiment of the present invention, a container is generally exemplified by a standardized metal material box used for transportation of cargo, but the present invention is not limited to this, It includes all nondestructive tests of the object.

1 and 2 are block diagrams of a container search system according to the present invention.

Referring to FIGS. 1 and 2, the container search system of the present invention includes a mobile frame 100 capable of moving along a search section, a linear accelerator 200 installed in the mobile frame 100 to generate radiation, A radiation irradiating unit 300 installed in the frame 100 for irradiating a radiation generated in the linear accelerator 200 to a container (a search target object), a container provided in the movable frame 100 so as to face the radiation irradiating unit 300, And a video output unit 500 for imaging and outputting the radiation signal detected by the radiation detecting unit 400. The radiation detecting unit 400 includes a radiation detector 400 for detecting transmission radiation of the radiation detector 400,

The container 10 is inspected in a state of being stopped in a search section, and the search interval corresponds to a section in which the mobile frame 100 moves for searching, and a guide rail for guiding the movement of the mobile frame 100 101 may be installed.

The moving frame 100 preferably includes a first moving part 110 in which the linear accelerator 200 and the irradiation part 300 are accommodated and movable and a second moving part 110 arranged in parallel with the first moving part 110, And a horizontal fixing unit 130 connecting and fixing the first moving unit 110 and the second moving unit 120 to each other.

The first moving part 110 may have a shielding structure capable of shielding high-energy electron beams and braking radiation X-rays that may be generated during operation of the linear accelerator 200. For example, And surrounds the linear accelerator 200 with a double shielding layer structure.

Preferably, the linear accelerator 200 has a resonance frequency of X-band (8 to 12 GHz) and accelerates the electron beam to generate radiation (X-ray,? -Ray) Can be manufactured to have a length of about 1 m or less and its weight is 10 kg or less, which is light and excellent in mobility. Specific embodiments will be described with reference to the related drawings.

The irradiation unit 300 irradiates the radiation generated in the linear accelerator 200 to the container and includes a waveguide and a collimator for converting the radiation output from the linear accelerator 200 into a cone beam having a fan shape. can do.

The radiation detecting unit 400 is disposed in the longitudinal direction of the second moving unit 120 to detect radiation, and a photoelectric sensor, which detects the transmission radiation and converts the radiation into an electric signal, .

The image output unit 500 processes the detection signal transmitted from the radiation detection unit 400 and outputs a perspective image of the container.

A cooling unit 610, a power supply unit 620, and a control unit 630, which are required to operate the linear accelerator 200, may be provided outside the moving frame 100.

The cooling unit 610 is for supplying cooling water for maintaining the linear accelerator 200 at a constant temperature, and includes a pump for circulating the cooling water.

The power supply unit 620 may supply an electric power required for operation of the electron accelerator 200 and may include an RF generator for generating an RF signal to the electron accelerator 200 for electron acceleration.

The control unit 630 is for monitoring and controlling the operation of the electronic accelerator 200. The control unit 630 is configured together with the video output unit 500 to search the perspective image of the container at a remote place and monitor and control the electromagnetic shorthand in an integrated manner .

 In this way, the auxiliary facilities can be connected to the first moving part 110 or the linear accelerator 200 by the flexible hose pipe or cable so that the cooling water or the power supply can be made, ). ≪ / RTI >

Although not shown, the moving frame 100 may be provided with its own driving source (motor), or it may be pulled and moved by a driving source installed on the ground.

3 is a configuration diagram of a linear accelerator according to a preferred embodiment of the present invention.

As illustrated in FIG. 3, the linear accelerator 200 of the present embodiment includes an acceleration tube 210 in which electrons are accelerated in a standing wave mode by an RF signal applied at a resonant frequency, An RF generator 240 for generating a high output RF signal in the acceleration tube 210, an electron gun 220, and an electron gun 220. The electron gun 220 generates an RF signal, And a pulse modulator 250 for generating a high-voltage DC pulse for operating the RF generator 240.

The pulse modulator 250 may be driven by a control signal applied by a separate control unit.

The acceleration tube 210 may be provided with a steering magnet or a solenoid magnet capable of accurately controlling the transmission of the electron beam. Although not shown, a vacuum pump is provided so that the cavity cell inside the acceleration tube maintains a high vacuum (~ 10 ^-8 torr).

The electron gun 220 may be a heat dissipation method in which electrons are emitted from a thermionic cathode by applying a DC voltage between the electrodes or may be a photoelectron emitting a photoelectron by irradiating laser light to a photo cathode, Lt; / RTI >

The RF generator 240 may be a magnetron or a klystron and is connected to the acceleration tube 210 by a waveguide 241.

Reference numeral 260 denotes an RF circulator which is provided between the RF generator 240 and the acceleration tube 210 so that energy reflected from the cavity of the acceleration tube 210 is returned to the RF generator 240 And protects the RF generator 240.

Also, the RF circulator 260 can transmit the RF signal reflected from the cavity of the acceleration tube 210 to an automatic frequency control system (AFC) (not shown). The AFC monitors and controls the reflected wave The frequency of the RF generator 240 can be adjusted through the unit to actively cope with the resonance frequency change of the acceleration tube 210 that may be generated during operation.

A target 270 is provided at an output end of the accelerating tube 210. An electron beam accelerated by the accelerating tube 210 is irradiated to the target 270 to generate radiation. For example, copper Tungsten (W) may be used.

4 is a cross-sectional view of an X-band linear acceleration tube according to a preferred embodiment of the present invention.

Referring to FIG. 4, the acceleration tube 210 according to the present embodiment has a resonance frequency of 9.3 GHz which is an X-band region and is composed of 24.5 common cells CS. The acceleration tube 210 has a resonance frequency of 10.5 The dog cavity cell induces a pulsed electron beam having the same resonance frequency as a bunching cell period BC and the remaining 14 common cells are used as an accelerating cell section AC to accelerate the electron beam. For reference, the energy gain in the home cell region (BC) is 122 to 245 keV, and the acceleration cell region has an electric field of 16 MV / m.

The acceleration tube 210 is manufactured by brazing a plurality of cell blocks having a cavity of? / 2, and the first cavity immediately adjacent to the cathode 221 is composed of half cell (0.5 cell) The electric field strength at the maximum is obtained. The remaining remaining common cells CS are made up of full cells and the size (length) of each common cell is determined by the speed of the electron beam as shown in the following equation (1). For reference, the common cell size of the acceleration tube according to the present embodiment is approximately 16 mm.

[Equation 1]

Above where v is _RF λ is the wavelength of the resonance frequency, v is the velocity of the electron beam, c is the speed of light.

Reference numerals 223 and 224 denote ports through which an ion pump for vacuum is connected. Reference numeral 225 denotes a coupler connected to the RF generator through a waveguide to receive an RF signal.

The diameter (d) and thickness (t) of the iris (IS) connecting the common cells were optimized by using CST MWS (CST MICROWAVE STUDIO). The diameter (d) and thickness (t) , Where the coupling factor k between the cavity cells is 2.1%.

The length of the accelerating tube manufactured in this way is ~ 0.4 m and its weight is 8 kg, and the electron beam energy at the output stage is 6 MeV or more.

Therefore, the linear accelerator having the resonance frequency of the X-band according to the present embodiment is small in size and light in weight, so that the nondestructive inspection can be performed by moving the radiation source while the search target is stationary.

In another embodiment of the present invention, the container search system of the present invention irradiates a container with two or more energy beams having different energy levels rather than a single energy, thereby obtaining a perspective image capable of distinguishing a hardly identifiable cargo with a single energy.

It is difficult to identify a thin-walled substance and a substance having a high effective atomic number (for example, a radioactive substance) when irradiating a container fre- quency by generating a single energy radiation (X-ray). Therefore, by analyzing the characteristics of each energy spectrum obtained by irradiating the target object with radiation of different energy, it is possible to search for a cargo (for example, organic matter / inorganic material or radiation material) difficult to be distinguished only by a single energy.

5, the linear accelerator 200 irradiates the vehicle 10 with pulsed radiation having different energies E1 and E2, and the radiation detecting unit 400 irradiates the vehicle 10 with energy Thereby detecting transmission energy.

Next, the perspective images IG1 and IG2 of the respective energies E1 and E2 are obtained. At this time, the cargoes 11 and 12 in the respective perspective images IG1 and IG2 are irradiated with energy E1 ) E2 are different from each other, the perspective images of the cargoes 11 and 12 are different from each other in the perspective images IG1 and IG2.

In the perspective image IG3 obtained by image-matching the perspective images IG1 and IG2 of each energy E1 and E2, it is possible to distinguish the cargoes 11 and 12 which are difficult to distinguish only by a single energy.

Referring to FIG. 1 again, the container search using the dual energy can be performed by controlling the radiation output energy of the linear accelerator 200 in the control unit 630, and the image output unit 500, And outputs a final perspective image through a matching process of perspective images of different energies.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be apparent to those of ordinary skill in the art.

100: moving frame 110: first moving part
120: second moving part 130: horizontal fixing part
200: linear accelerator 210: acceleration tube
220: electron gun 230: electron gun driving unit
240: RF generator 250: Pulse modulator
300: radiation irradiation part 400: radiation detection part
500: Video output unit

Claims (6)

A moving frame capable of moving along a search section;
A linear accelerator installed in the moving frame for generating radiation;
A radiation irradiator installed in the moving frame for irradiating the object to be examined with radiation generated in the linear accelerator;
A radiation detecting unit installed on the moving frame so as to face the radiation applying unit and detecting transmitted radiation of a search target;
And an image output unit for imaging and outputting the radiation signal detected by the radiation detecting unit. The system of claim 1, wherein the linear accelerator generates radiation by accelerating an electron beam by an X-band (8 to 12 GHz) resonance frequency. 3. The linear accelerator according to claim 2,
An acceleration tube in which electrons are accelerated in a standing wave mode by an RF signal applied at an X-band resonance frequency;
An electron gun for generating electrons in the acceleration tube;
An electron gun driving unit for supplying driving power to the electron gun;
An RF generator for generating an RF signal in the acceleration tube;
And a pulse modulator for generating a high voltage DC pulse for operating the electron gun and the RF generator. The system of claim 3, further comprising a control unit for controlling the output energy of the electron beam output from the acceleration tube by controlling the output of the pulse modulator. 5. The system of claim 4, wherein the image output unit matches the perspective images with respect to radiation of different energy output from the linear accelerator. The mobile terminal according to claim 1,
A first moving unit capable of receiving and moving the linear accelerator and the irradiation unit;
A second moving unit disposed in parallel with the first moving unit and capable of receiving and moving the radiation detecting unit;
And a horizontal fixing unit connecting and fixing the first moving unit and the second moving unit to each other.

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