CN103901064A - Ray emission device, imaging system and inspection method - Google Patents

Abstract

A radiation emitting device includes: a radiation source emitting radiation; and a rotating mechanism that can rotate around a rotation axis, a part of the rotating mechanism that can rotate around the radiation source, and a part of the rotating mechanism that has an opening through which the radiation can pass. , the opening of the rotating mechanism includes a slit. Compared with the prior art, the present invention enables one scan to simultaneously form a transmission image and a backscattering image, and integrates backscattering and transmission imaging technologies, which can not only effectively identify substances with low atomic numbers, but also perform well on deep objects. Identification, which not only improves the scanning speed but also improves the identification ability of items.

Description

Radiation emission device, imaging system and inspection method

technical field

The invention relates to a ray emitting device, an imaging system and an inspection method.

Background technique

Transmission imaging technology is suitable for monitoring that requires high penetration and high spatial resolution. It is more sensitive to materials with high density and high atomic number, and less sensitive to materials with low density and low atomic number.

Imaging through backscattering technology can detect the structure of the object to be inspected, so that low-density, low-atomic-number substances, such as explosives and detonators, stand out in the image background. It is especially suitable for the monitoring of dangerous goods with certain occluders on the surface.

Backscatter and transmission imaging have been widely used as separate scanning systems, but there is a need for simultaneous backscatter and transmission imaging systems and methods.

Contents of the invention

It is an object of the present invention to provide a radiation emitting device, an imaging system and an inspection method whereby backscatter and transmission imaging are performed simultaneously.

According to one aspect of the present invention, the present invention provides a radiation emitting device, the radiation emitting device includes: a radiation source emitting radiation; The source rotates and part of the rotating mechanism has an opening through which the radiation can pass, said opening of the rotating mechanism comprising a slit.

According to an aspect of the invention, said part of said rotating mechanism is an annular part.

According to an aspect of the present invention, the slits are substantially on the same plane.

According to an aspect of the invention, said plane is substantially perpendicular to the axis of rotation of the rotary mechanism.

According to one aspect of the present invention, the ray emitting device further includes a ray guiding device connected to the ray source, the ray guiding device has a ray inlet connected to the ray source, and a ray that causes the ray to be emitted from the ray guiding device The part of the rotating mechanism can rotate on the radiation outlet of the radiation guiding device relative to the radiation outlet of the radiation guiding device.

According to an aspect of the present invention, said opening comprises two said slits spaced apart in the circumferential direction.

According to an aspect of the present invention, the opening further includes a pencil-shaped beam hole spaced apart from the slit in the circumferential direction in the portion of the rotation mechanism.

According to one aspect of the present invention, the radiation beam emitted by the radiation source is formed into a fan-shaped radiation beam by the radiation guiding device.

According to an aspect of the present invention, the radiation guiding device is arranged between the radiation source and the part of the rotating mechanism.

According to one aspect of the present invention, the present invention provides an imaging system, the imaging system comprising: the above-mentioned radiation emitting device; and a detector for detecting the radiation emitted by the radiation emitting device.

According to an aspect of the present invention, the detector is a backscatter detector for detecting the backscattered rays scattered by the rays emitted by the ray emitting device on the inspected object; and for detecting the backscattered rays emitted by the ray emitting device 1. At least one of the transmission detectors for rays passing through the object to be inspected.

According to an aspect of the present invention, the present invention provides an inspection method, the inspection method comprising: forming a fan-shaped ray beam, the fan-shaped ray beam gradually increases from a fan angle of zero degrees to a predetermined fan angle.

According to an aspect of the present invention, when the fan-shaped ray beam reaches a predetermined fan-shaped angle, a transmission detector is used to receive the fan-shaped ray beam after passing through the inspected object to obtain transmission data.

According to an aspect of the present invention, the inspection method further includes: during the process of the fan-shaped ray beam gradually increasing from a zero-degree fan angle to a predetermined fan-shaped angle, using a backscatter detector to receive the backscattering of the fan-shaped ray beam on the object to be inspected Scatter rays to obtain backscatter data or backscatter signals.

According to an aspect of the present invention, the predetermined sector angle is a maximum sector angle.

According to an aspect of the present invention, the inspection method further includes: gradually reducing the fan-shaped ray beam from a predetermined fan angle to zero-degree fan angle, and using a backscatter detector to receive backscattered rays scattered by the fan-shaped ray beam on the inspected object to obtain backscatter data or backscatter signals.

According to an aspect of the present invention, the inspection method further includes: forming a pencil beam before forming a fan beam; and using a backscatter detector to receive the backscattered rays scattered by the pencil beam on the object to be inspected to obtain the backscatter data or backscattered signal.

According to an aspect of the present invention, the inspection method further includes: forming a pencil beam; and using a backscatter detector to receive backscattered rays scattered by the pencil beam on the inspected object to obtain backscatter data or backscatter signals.

According to an aspect of the present invention, the substance information of a region in a column of inspected regions of the inspected object is subtracted from the backscattered signals obtained from a plurality of regions including the one region in a row of inspected regions The multiple regions are obtained by subtracting the backscattered signals obtained in the remaining regions of the one region.

According to one aspect of the present invention, when the fan-shaped ray beam gradually increases from a zero-degree fan angle to a predetermined fan-shape angle, N inspection areas are generated on the object to be inspected, and the irradiation range of the fan-shaped ray beam extends from the first inspection area to the Nth inspection area. In the inspection area, the inspection method includes: when the irradiation range of the fan-shaped ray beam is in the first inspection area, using a backscatter detector to obtain a backscatter signal S ₁ representing material information in the first inspection area; When the range is from the first inspection area to the i-1th inspection area, the backscattered detector is used to receive the backscattered rays scattered from the first inspection area to the i-1th inspection area to generate a backscattered signal S _i-1 ; When the irradiation range of the ray beam is in the first inspection area to the i-th inspection area, a backscattered detector is used to receive the backscattered rays scattered from the first inspection area to the i-th inspection area to generate a backscattered signal S _i ; and the backscattered Subtract the backscatter signal _{S i-1} from the signal S i to obtain material information representing the i-th inspection region, where i is a natural number equal to 2 to N.

According to one aspect of the present invention, when the fan-shaped ray beam gradually decreases from a predetermined fan angle to zero-degree fan angle, N inspection areas are generated on the object to be inspected, and the irradiation range of the fan-shaped ray beam is from the first inspection area to the Nth inspection area. The inspection area is gradually reduced to the first inspection area, and the inspection method includes: when the irradiation range of the fan-shaped ray beam is in the first inspection area to the i-th inspection area, using a backscatter detector to receive data from the first inspection area to the i-th inspection area Backscattered rays scattered by the inspection area to generate backscattered signals S _i ; when the irradiation range of the fan-shaped ray beam is from the first inspection area to the i-1th inspection area, the backscatter detector is used to receive signals from the first inspection area to the i-th inspection area -1 The backscattered rays scattered by the inspection area to generate the backscattered signal S _i-1 ; the backscattered signal S _i is subtracted from the backscattered signal S _i-1 to obtain the material information representing the i-th inspection area; and in the fan-shaped ray beam When the irradiation range is in the first inspection area, a backscatter signal S ₁ representing material information in the first inspection area is obtained by using a backscatter detector, wherein i is a natural number equal to 2 to N.

According to an aspect of the present invention, the inspection method further includes: processing the backscatter data, wherein by processing the backscatter data, it is judged whether there are prohibited items on the inspected object according to the processing result. By processing the transmission data, it is judged whether there are prohibited items in the inspected object according to the processing result.

The present invention forms flying spots and fan beams at intervals, so that the scanning system simultaneously forms transmission images and backscatter images in one scan, which can not only effectively solve the sensitivity of low atomic number substances, but also well solve the monitoring of deep objects.

Description of drawings

Fig. 1 is a schematic perspective view of an imaging system according to the present invention, wherein a fan-shaped beam of rays is emitted through a slit.

Fig. 2 is a schematic perspective view of an imaging system according to the present invention, wherein a pencil beam is emitted through a pencil beam aperture.

FIG. 3 is a schematic diagram of the positional relationship between the slit and the pencil beam hole of the rotation mechanism of the imaging system according to the present invention.

FIG. 4 is a schematic diagram of the positional relationship of two slits of the rotation mechanism of the imaging system according to the present invention.

Figure 5(a) and Figure 5(b) are schematic diagrams of backscatter signal amplitude P before and after backscatter subtraction processing according to the present invention, wherein the abscissa represents time, and the ordinate represents signal amplitude P.

Fig. 6 is a schematic diagram of the radiation emitting device of the imaging system according to the present invention.

7a to 7d show schematic diagrams of subtraction processing of backscattered signals according to an embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1-2, the imaging system 100 according to the present invention includes: a ray emitting device 102; a backscatter detector 4 for receiving the backscattered rays scattered by the rays emitted by the ray emitting device 102 on the inspected object ; and the transmission detector 5 for receiving the radiation emitted by the radiation emitting device 102 and passing through the object to be inspected. The backscatter detector 4 may be a flat panel detector, and the transmission detector 5 may be an array detector. Imaging system 100 is capable of simultaneous backscatter and transmission imaging.

As shown in Figures 1-4 and 6, the radiation emitting device 102 according to the present invention includes: a radiation source 3 such as an X-ray machine emitting radiation; a radiation guiding device 2 connected to the radiation source 3, the radiation guiding device 2 There is a ray inlet connected to the ray source 3, and a ray outlet for the ray to be emitted from the ray guiding device; and a rotating mechanism 1, the rotating mechanism 1 has a rotatable ring part 11, the inner surface of the ring part 11 The radiation outlet of the radiation guiding device 2 is covered, and the annular portion 11 has an opening through which the radiation can pass. The radiation guide 2 is formed of a radiation shielding material and may be a collimator. If the radiation emitted by the radiation source 3 has been collimated, the radiation guiding device 2 can be omitted. The swivel mechanism may not include the ring portion, alternatively the swivel mechanism may include other shaped portions, for example only a part of the ring portion.

As shown in Figures 1, 2, 3 and 4, the radiation source 3 is approximately at the rotation center C of the rotation mechanism. For example, the target point of the ray source 3 is approximately at the rotation center C. The radiation source 3 is arranged on the frame 6 . The radiation source 3 can be controlled to emit radiation and stop emitting radiation as required.

A driving device 12 such as a motor and a reducer is connected to the rotating mechanism 1 and drives the rotating mechanism 1 to rotate. The annular part 11 or other parts of the rotating mechanism 1 are equipped with a position sensing switch, and when the rotating mechanism 1 rotates around the radiation source 3, the position information of the annular part 11 or other parts is fed back in real time. As shown in FIG. 6 , the rotating mechanism 1 is fixed on the frame 6 through the bearing seat 17 , and at the same time, the rotating mechanism 1 is connected with the motor 12 through the coupling 18 . The rotating mechanism 1 is formed of a radiation shielding material. The rotating mechanism 1 can rotate in both forward and reverse directions.

As shown in FIGS. 1 and 2 , the opening includes a slit 13 disposed along the circumferential direction of the annular portion 11 and a pencil beam hole 14 spaced apart from the slit 13 in the circumferential direction. The slit may be a fan beam slit. The slits 13 may be substantially on one plane. As shown in FIG. 3 , the pencil beam hole 14 has a center line passing through the rotation center C of the annular portion, and the slit 14 is symmetrical with respect to the center line.

As shown in FIG. 4 , as an option, the opening includes two slits 13 arranged along the circumferential direction of the annular portion 11 and spaced apart in the circumferential direction of the annular portion 11 . The fan angle of the two slits 13 may not be greater than 90 degrees. Each of the two slits 13 is approximately symmetrical with respect to a line passing through the center of rotation C of the annular portion 11 .

As shown in Figures 1-2, the radiation guiding device 2 may have a substantially fan-shaped shape. The radiation beam is shaped into a fan-shaped radiation beam by the radiation guiding device 2 . The radiation guiding device 2 is arranged between the radiation source 3 and the annular portion 11 of the rotating mechanism 1 . A labyrinth structure is formed between the ray guiding device 2 and the rotating mechanism 1 to prevent rays from leaking from between the ray guiding device 2 and the rotating mechanism 1 . For example, the fan-shaped shielding body of the radiation guiding device 2 and the rotating shielding body of the rotating mechanism 1 adopt a non-contact labyrinth shielding design to ensure that the radiation does not leak. The fan-shaped slots on the fan-shaped shielding body of the ray guiding device 2 and the slots of the annular portion 11 of the rotating mechanism 1 are in the same plane.

When the imaging system 100 is running, the motor 12 drives the ring part 11 of the rotating mechanism to rotate. During the scanning process, the radiation source 3 releases radiation with a certain energy, and the radiation beam is formed into a fan-shaped radiation beam by the fan-shaped radiation guide device 2. When rotating When the annular part 11 of the mechanism turns to the position shown in Figure 1, the fan-shaped ray beam 15 is released to the channel, and the array detector 5 collects the transmission information through the position information fed back by the position sensing switch.

With the relative movement of the annular part 11 and the fan-shaped ray guiding device 2, the fan-shaped ray beam 15 gradually expands from the initial single point to the entire fan, and then the fan gradually becomes smaller until there is no ray at the end, and the illuminated objects in the channel 15 are also sequentially From one direction it gradually expands to the whole being illuminated, and from the other direction it gradually fades away. The signal collected by the flat panel detector 4 at each moment reflects the backscattering information of the object irradiated by the fan-shaped ray beam in the current shape. If the signal collection time is fast enough or the object in the channel moves slowly, most of the signals collected before and after are The overlapping information means that the latter has the shadow of the former, and the information of the difference between the two reflects the information of the illuminated object after the expansion of the fan-shaped ray beam.

Figure 5(a) and Figure 5(b) are schematic diagrams of backscatter signal amplitude P before and after backscatter subtraction processing according to the present invention, wherein the abscissa represents time, and the ordinate represents signal amplitude P. As shown in Fig. 5(a) and Fig. 5(b), the backscattering information with the position signal is formed through the subtraction algorithm. Specifically, Figure 5(a) is a schematic diagram of the signal amplitude P without subtraction algorithm processing, and Figure 5(b) is the subtraction algorithm obtained by subtracting adjacent signal amplitudes P A schematic diagram of the signal.

When the fan-shaped ray beam gradually expands from the fan-shaped angle of 0 angle, the flat panel detector 4 collects the backscatter information of the fan-shaped ray beam, and processes the backscatter information with the position signal through subtraction algorithm. The annular part 11 of the rotating mechanism continues to rotate. After the fan-shaped beam is gradually reduced from the maximum fan angle to 0 degree fan angle, the pencil-shaped beam hole 14 of the rotating mechanism 1 releases the pencil-shaped beam 16, as shown in FIG. 2 , the flat-panel detection The device 4 collects the backscattering information of the pencil beam, and feeds back an additional position signal through the position of the rotating mechanism. In this way, the annular part of the rotating mechanism rotates once, and the array detector 5 and the flat panel detector 4 acquire transmission information and backscatter information respectively, and generate a transmission image and a backscatter image respectively.

As shown in FIG. 4, when the slit 13 is used, a backscattered image can be obtained by using the slit 13 and "subtraction processing". One slit 13, or multiple slits 13, or one slit 13 and one pencil beam hole 14 can be used according to actual requirements.

In the present invention, the fan-shaped ray guiding device 2 is connected with the ray source 3 to form a fan-shaped ray beam with a certain width, and the fan-shaped opening angle of the fan-shaped ray beam is determined by the height of the object to be monitored; the rotating mechanism roughly rotates with the ray source as the center of the circle , there is a slit on one side of the rotating mechanism, the fan-shaped opening angle of the slit may not be larger than that of the fan-shaped ray guiding device, and a small transmission hole is opened on the other side, forming a gap between the rotating mechanism and the fan-shaped ray guiding device The labyrinth structure does not hinder the rotation of the rotating mechanism, but also ensures that the rays are only emitted from the slits or small transmission holes of the rotating mechanism. Every time the rotating mechanism rotates once, a complete fan-shaped ray beam and a series of continuous flying spots can be formed. Light spot; the position sensing switch of the rotating mechanism feeds back the rotation position of the rotating mechanism to the upper computer at any time; the flat panel detector collects the backscattered ray signal, and several flat panel detectors can be arranged, and the flat panel detector is converted into position information through timing information; the line array detector Located directly in front of the beam, it is composed of vertically arranged pencil-shaped detectors, which collect transmission signals after passing through the monitored object to form a transmission image. Every time the rotating mechanism rotates once, the line array detector collects a column of transmission signals, and the flat panel detector collects a column of flying-spot backscatter signals to form transmission and backscatter images. At the same time, when the beam exits from the slit, a series of backscattering signals can be collected through timing control, and more backscattering images can be obtained through subtraction processing.

The inspection method according to the present invention is described below.

In step 11, a fan-shaped ray beam is formed, and the fan-shaped ray beam gradually increases from a zero-degree fan angle to a predetermined fan-shaped angle. The fan beam scatters the backscattered rays on the object under inspection to obtain a backscattered signal. The predetermined sector angle may be a maximum sector angle. Obviously, the radiation source can be stopped to emit radiation at a predetermined fan angle.

In step 13, when the fan-shaped beam reaches a predetermined fan angle, a transmission detector is used to receive the fan-shaped beam after passing through the inspected object to obtain transmission data.

In step 15, the fan beam is gradually reduced from a predetermined fan angle to zero fan angle, and a backscatter detector is used to receive backscattered rays scattered by the fan beam on the inspected object to obtain backscatter data or backscatter signals. For example, the rotation mechanism may be reversed to gradually reduce the fan beam from a predetermined fan angle to a zero degree fan angle.

In step 17, forming a pencil beam; and receiving backscattered rays scattered by the pencil beam on the inspected object by a backscatter detector to obtain backscatter data or backscatter signals. Alternatively, before forming the fan beam, a pencil beam can be formed; and a backscatter detector is used to receive the backscattered rays scattered by the pencil beam on the inspected object to obtain backscatter data or backscatter signals.

In step 19, the backscatter data is processed, and whether there are prohibited items on the inspected object is judged according to the processing result, and the transmission data is processed, and whether there are prohibited articles in the inspected object is judged according to the processing result.

As shown in Figures 7a, 7b, 7c, 7d and with reference to Figures 1 and 3, when the fan-shaped ray beam 15 gradually increases from zero fan angle to a predetermined fan angle, N inspection regions P1 to P are generated on the object ₂₅ to be inspected _n , the irradiation range of the fan-shaped ray beam 15 extends from the first inspection area P ₁ to the Nth inspection area P _n , and the inspection method further includes: when the irradiation range of the fan-shaped ray beam 15 is in the first inspection area P ₁ , using The backscatter detector 4 obtains the backscatter signal _S1 representing the material information of the first inspection region _P1 ; when the irradiation range of the fan-shaped ray beam 15 is in the first inspection region _P1 to the i-1th inspection region P _i-1 , using the backscatter detector 4 to receive backscattered rays 21 scattered from the first inspection region P ₁ to the i-1th inspection region P _i-1 to generate backscattered signals S _i-1 ; in the irradiation range of the fan-shaped ray beam 15 When in the first inspection area P ₁ to the i-th inspection area P _i-1 , the backscattered ray 21 scattered from the first inspection area P ₁ to the i-th inspection area P _i is received by the backscatter detector 4 to generate a backscatter signal S _i ; and subtracting the back-scatter signal S _{i -1} from the back-scatter signal S i to obtain material information representing the i-th inspection region _Pi , wherein i is a natural number equal to 2 to N.

As shown in Figures 7a, 7b, 7c, 7d and with reference to Figures 1 and 3, when the fan-shaped beam 15 gradually decreases from a predetermined fan angle to a zero-degree fan angle, N inspection regions _P1 are generated on the inspected object 25 From the first inspection area P ₁ to the Nth inspection area P _n , the irradiation range of the fan-shaped ray beam 15 gradually decreases to the first inspection area P ₁ , and the inspection _method also includes: When the range is from the first inspection area _P1 to the i-th inspection area P _i , use the backscatter detector 4 to receive the backscattered rays 21 scattered from the first inspection area _P1 to the i-th inspection area P _i to generate a backscatter signal S _i ; when the irradiation range of the fan-shaped ray beam 15 is in the first inspection area P ₁ to the i-1th inspection area P _i-1 , use the backscatter detector 4 to receive inspections from the first inspection area P ₁ to the i-1th inspection area Scattering the backscattered rays scattered by P _i-1 in the region to generate backscattered signal S _i-1 ; subtracting the backscattered signal S _{i -1} from the backscattered signal S i to obtain material information representing the i-th inspection region P _i ; and in When the irradiation range of the fan beam 15 is in the first inspection area _P1 , the backscatter signal _S1 representing the material information of the first inspection area _P1 is obtained by using the backscatter detector 4, where i is a natural number equal to 2 to N.

Therefore, it is obvious that, except for the first inspection region _P1 , the material information of an area in a column of inspected areas of the inspected object is obtained from a plurality of areas in a column of inspected areas that include the one area. The scatter signal is obtained by subtracting a backscatter signal obtained from a region remaining except the one region from the plurality of regions.

The backscatter subtraction processing will be described in detail below in conjunction with FIGS. 7a, 7b, 7c, and 7d.

As shown in Figure 7a and with reference to Figures 1 and 3, when the annular portion 11 rotates at an angular velocity ω, the rays emitted by the radiation source 3 pass through the slit 13 of the annular portion 11 to form a beam of radiation 15, and the beam of radiation 15 is irradiated on the object 25. position or area P ₁ , at this time, the backscattered ray 25 scattered from the position or area P ₁ of the object 25 is received by the backscatter detector 4, thereby generating a backscatter signal S ₁ , which may not be transmitted from the transmission detector 5 Get a signal. The backscattered signal _S1 represents the position of the object or material information of the area _P1 .

As shown in Figure 7b and with reference to Figures 1 and 3, when the annular portion 11 continued to rotate at an angular velocity ω, the rays emitted by the radiation source 3 formed a beam 15 through the slit 13 of the annular portion 11, and the slit 13 and the ray The overlapping portion of the guide 2 is increased, so that the beam 15 is broadened, the beam 15 impinges on the positions or areas _P1 and _P2 of the object 25, and is now scattered from the positions or areas _P1 and _P2 of the object 25 The backscattered rays 25 are received by the backscatter detector 4 , thereby generating a backscatter signal S ₂ , and no signal can be obtained from the transmission detector 5 at this time. The signal S _{2 -S} 1 obtained by subtracting the back-scatter signal S ₁ from the back-scatter signal _{S 2 represents} the position of the object or the material information of the area P ₂ .

As shown in Figure 7c and with reference to Figures 1 and 3, when the annular portion 11 continued to rotate at an angular velocity ω, the rays emitted by the radiation source 3 formed a beam 15 through the slit 13 of the annular portion 11, and the slit 13 and the ray The overlapping portion of the guiding device 2 is further increased, so that the beam 15 is further widened, and the beam 15 is irradiated on the positions or areas P ₁ , P ₂ and P ₃ of the object 25, at this time, from the position or area P of the object 25 The backscattered rays 25 scattered by ₁ , P ₂ and P ₃ are received by the backscatter detector 4 , thereby generating a backscatter signal S ₃ , which may not be obtained from the transmission detector 5 at this time. The signals S ₃ -S 2 obtained by subtracting the back-scatter signal S ₂ from the back-scatter signal _{S 3 represent} the position of the object or the material information of the area P ₃ .

Repeat the above-mentioned process until, for example, the overlapping portion of the slit 13 and the ray guiding device 2 reaches a predetermined value, such as reaching a maximum value or a part of the maximum value, as shown in FIG. 7d and with reference to FIGS. On the position or area P ₁ , P ₂ , P ₃ ... P _n , at this time, the backscattered ray 25 scattered from the position or area P ₁ , P ₂ , P ₃ ... P _n of the object 25 is detected by the backscatter detector 4 receiving, thus generating a backscatter signal S _n , and at this time the transmission detector 5 can receive the transmitted ray 23 passing through the object, thereby generating a transmission signal TS ₁ . The signal _{Sn- Sn-1 obtained by subtracting the backscatter signal Sn- 1} from the backscatter signal _Sn represents the position of the object or the material information of the region _Pn .

Through the above method, a column of material information from top to bottom of the object 25 can be obtained, and at the position or area _Pn , the projected ray covers the transmission detector 5, thereby obtaining a column of transmission information.

As the annular portion 11 rotates at an angular velocity ω, the object 25 moves relative to the ray plane in a direction perpendicular to the ray plane, so that the full backscattered signal and the full transmitted signal of the object 25 are obtained.

Claims (21)

1. a ray emission device, comprising:

Send the radiographic source of ray; And

Rotating mechanism, this rotating mechanism can rotate around rotation, and the part of this rotating mechanism can be rotated around radiographic source, and the part of this rotating mechanism has the opening that can make ray pass through, and the described opening of this rotating mechanism comprises slit.

2. ray emission device according to claim 1, the described part of wherein said rotating mechanism is annulus.

3. ray emission device according to claim 1, wherein said slit roughly at grade.

4. ray emission device according to claim 3, wherein said plane is substantially vertical with the rotation of rotating mechanism.

5. ray emission device according to claim 1, also comprise the ray guidance device being connected with radiographic source, this ray guidance device has the ray import being connected with radiographic source, and the ray outlet that ray is penetrated from this ray guidance device, the described part of described rotating mechanism can be rotated in the ray outlet of this ray guidance device in the described ray outlet with respect to described ray guidance device.

6. ray emission device according to claim 1, wherein said opening comprises two isolated described slits in a circumferential direction.

7. ray emission device according to claim 1, wherein said opening is also included in the described part of rotating mechanism and described slit isolated form of a stroke or a combination of strokes ray beam hole in a circumferential direction.

8. ray emission device according to claim 5, the beam wherein by ray guidance device, radiographic source being sent is formed as fan-ray beam.

9. ray emission device according to claim 5, wherein said ray guidance device is arranged between the described part of described radiographic source and described rotating mechanism.

10. an imaging system, comprising:

Ray emission device according to claim 1; And

For receiving the detector of the ray that ray emission device sends.

11. imaging systems according to claim 10, wherein said detector is the backward scattering detector of the ray backward scattering ray of scattering on inspected object for receiving described ray emission device transmitting; And for receiving at least one of the transmission detectors transmitting of described ray emission device, that see through the ray after inspected object.

12. 1 kinds of inspection methods, comprising:

Form fan-ray beam, this fan-ray beam is increased to predetermined fan angle from zero degree segment angle gradually.

13. inspection methods according to claim 12, wherein

In the time that this fan-ray beam reaches predetermined fan angle, utilize transmission detectors to receive through the described fan-ray beam after inspected object and see through data to obtain.

14. inspection methods according to claim 12, also comprise:

Be increased to the process of predetermined fan angle from zero degree segment angle gradually at this fan-ray beam,

Utilize the backward scattering ray of backward scattering detector reception fan-ray beam scattering on inspected object to obtain backscatter signal.

15. inspection methods according to claim 12, wherein

Described predetermined fan angle is maximum segment angle.

16. according to the inspection method described in claim 12 or 14, also comprises:

Make fan-ray beam be reduced to zero degree segment angle from predetermined fan angle gradually, and

Utilize the backward scattering ray of backward scattering detector reception fan-ray beam scattering on inspected object to obtain backward scattering data.

17. inspection methods according to claim 12, also comprise:

Before forming fan-ray beam, form form of a stroke or a combination of strokes beam; And

Utilize the backward scattering ray of backward scattering detector reception form of a stroke or a combination of strokes beam scattering on inspected object to obtain backscatter signal.

18. according to the inspection method described in claim 12 or 16, also comprises:

Form form of a stroke or a combination of strokes beam; And

Utilize the backward scattering ray of backward scattering detector reception form of a stroke or a combination of strokes beam scattering on inspected object to obtain backscatter signal.

19. according to the inspection method described in claim 14 or 16, wherein:

One row of inspected object are examined the material information in a region in region, deduct and remove the backscatter signal that remaining region, a described region obtains from the plurality of region and obtain by be examined backscatter signal that multiple regions region, that comprise a described region obtain from row.

20. inspection methods according to claim 14, wherein;

In the time that this fan-ray beam is increased to predetermined fan angle from zero degree segment angle gradually, on inspected object, produce N inspection area, the range of exposures of fan-ray beam extends to N inspection area from the first inspection area,

Described inspection method comprises:

During in the first inspection area, utilize backward scattering detector to obtain the backscatter signal S of the material information that represents the first inspection area in the range of exposures of fan-ray beam ₁;

During in the first i-1 inspection area, inspection area to the, utilize backward scattering detector to receive from the backward scattering ray of the first inspection area to the i-1 inspection area scattering to produce backscatter signal S in the range of exposures of fan-ray beam _i-1;

During in the first i inspection area, inspection area to the, utilize backward scattering detector to receive from the backward scattering ray of the first inspection area to the i inspection area scattering to produce backscatter signal S in the range of exposures of fan-ray beam _i; And

By backscatter signal S _ideduct backscatter signal S _i-1obtain the material information that represents i inspection area,

Wherein i equals 2 to N natural number.

21. inspection methods according to claim 16, wherein;

In the time that this fan-ray beam is reduced to zero degree segment angle from predetermined fan angle gradually, on inspected object, produce N inspection area, the range of exposures of fan-ray beam is reduced to the first inspection area gradually from the first N inspection area, inspection area to the,

Described inspection method comprises:

During in the first i inspection area, inspection area to the, utilize backward scattering detector to receive from the backward scattering ray of the first inspection area to the i inspection area scattering to produce backscatter signal S in the range of exposures of fan-ray beam _i;

During in the first i-1 inspection area, inspection area to the, utilize backward scattering detector to receive from the backward scattering ray of the first inspection area to the i-1 inspection area scattering to produce backscatter signal S in the range of exposures of fan-ray beam _i-1;

By backscatter signal S _ideduct backscatter signal S _i-1obtain the material information that represents i inspection area; And

During in the first inspection area, utilize backward scattering detector to obtain the backscatter signal S of the material information that represents the first inspection area in the range of exposures of fan-ray beam ₁,

Wherein i equals 2 to N natural number.

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