CN108400079A - Pencil beam X-ray tubes and backscatter detection equipment - Google Patents

Abstract

The present disclosure provides a pencil beam X-ray tube and a backscatter detection device. The pencil beam X-ray tube comprises: a housing; the anode, at least one end of the anode is arranged in the shell, and the end surface of the at least one end is not perpendicular to the length extension direction of the anode; a target disposed on at least one end face of the anode; a cathode configured to face the target and capable of emitting electrons to the target; and a pencil beam module disposed near the at least one end of the anode for modulating the X-rays generated by the target into a pencil X-ray beam emitted from a pencil X-ray tube.

Description

Pencil beam X-ray tubes and backscatter detection equipment

technical field

Embodiments of the present disclosure relate to the technical field of radiation generation, in particular to pencil beam X-ray tubes and backscatter detection equipment.

Background technique

Backscatter imaging technology has been widely used in the field of safety inspection of human body, goods and vehicles due to its advantages of low radiation dose, good safety and sensitivity to light materials. The backscatter imaging technology uses a pencil beam scanning method, so the fan beam or cone beam generated by a conventional X-ray tube needs to be modulated into a pencil beam.

However, a conventional pencil beam scanning device includes an X-ray tube assembly, a high-voltage power supply, a pencil beam scanning and its driving mechanism, etc., and the components are relatively large and scattered. This limits its application in small or portable products.

Contents of the invention

According to an aspect of the present disclosure, there is provided a pencil beam X-ray tube comprising:

shell;

An anode, at least one end of the anode is arranged in the casing, and the end surface of the at least one end is not perpendicular to the length extension direction of the anode;

a target disposed on at least one end face of the anode;

a cathode configured to face the target and capable of emitting electrons to the target; and

The pencil beam module is configured near the at least one end of the anode to modulate the X-rays generated by the target into a pencil beam of X-rays emitted from the pencil beam X-ray tube.

In one embodiment, the pencil beam module includes a guard tumbler, wherein the guard tumbler surrounds at least one end of the anode and allows electrons emitted by the cathode to reach the target, shielding scattered electrons and x-rays generated by the target.

In one embodiment, the protective drum is provided with at least one ray exit hole for modulating the X-rays generated by the target to form at least one pencil-shaped X-ray.

In one embodiment, the protective drum is configured to be rotatable around the anode, so that at least one pencil-shaped X-ray beam formed through at least one radiation exit hole can scan within a certain angle range.

In one embodiment, the pencil beam module includes an armature core disposed on the anode close to at least one end and an armature winding wound around the armature core, and the corresponding armature core is disposed on the inner wall of the protective drum A plurality of permanent magnets, so that when the armature winding forms a changing magnetic field, the armature winding interacts with the plurality of permanent magnets to drive the guard drum to rotate.

In one embodiment, the pencil beam module further includes a driver connected to an external power source and providing a varying current to the armature winding.

In one embodiment, the pencil beam module includes a bearing disposed on the anode, the bearing supporting the guard tumbler to allow the guard tumbler to rotate about the anode.

In one embodiment, the anode includes a wiring duct for arranging power lines and signal lines electrically connecting the pencil beam module to the outside.

In one embodiment, the pencil X-ray beam emitted from the pencil beam module is perpendicular to the length extension direction of the anode.

In one embodiment, the pencil X-ray beam emerging from the pencil beam module is at an angle to the length extension direction of the anode.

Another aspect of the present disclosure provides a backscatter detection device, including the above-mentioned pencil beam X-ray tube.

Description of drawings

FIG. 1 shows a schematic cross-sectional view of a pencil beam X-ray tube according to an embodiment of the present disclosure;

Figure 2 shows a schematic cross-sectional view of a pencil beam X-ray tube according to an embodiment of the present disclosure;

Fig. 3 shows the structure of the sealing joint of an embodiment of the present disclosure;

FIG. 4 shows a schematic diagram of pencil X-ray beam scanning according to an embodiment of the present disclosure.

Detailed ways

While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that the accompanying drawings and detailed description are not intended to limit the disclosure to the precise form disclosed, but on the contrary, are intended to cover what falls within the spirit and scope of the disclosure as defined by the appended claims All modifications, equivalents and alternatives in . The drawings are for illustration purposes and are not drawn to scale.

Terms such as "upper" and "lower" are used in this specification not to limit the absolute orientation of components, but to describe relative positions of components in the view to facilitate understanding. "Top side" and "bottom side" in this specification refer to the orientations of the upright side and the lower side of an object in general.

Various embodiments according to the present disclosure are described below with reference to the accompanying drawings.

Referring to FIG. 1 , a cross-sectional view of a pencil beam X-ray tube provided by an embodiment of the present disclosure is shown. The pencil beam X-ray tube includes: a casing; an anode, at least one end of which is arranged in the casing, and the end face of the at least one end is not perpendicular to the length extension direction of the anode. The pencil beam X-ray tube further includes a target disposed on at least one end face of the anode; a cathode configured to face the target and capable of emitting electrons to the target; and a pencil beam module configured to the anode The vicinity of the at least one end is used to modulate the X-rays generated by the target into a pencil-shaped X-ray beam emitted from the pencil-shaped beam X-ray tube.

In Fig. 1, the majority of the anode 5 is shown placed within the housing 6 of the pencil beam X-ray tube. The end surface of the left end of the anode 5 is not in the vertical direction, but faces obliquely downward.

The cathode 4 may include a filament 41 , a focusing mask 42 and a filament lead 43 . The filament lead wire 43 is connected to the negative pole of the high voltage power supply and the filament power supply for emitting electrons. The focusing cover 42 is used to focus electrons and also plays a supporting role. The focusing mask 42 is provided with an electron exit hole 44 to emit electrons toward the position of the target 53 . The target 53 generates X-rays under the bombardment of electrons emitted by the cathode 4 .

In an embodiment of the present disclosure, a pencil beam module is provided inside the housing 6 of the pencil beam X-ray tube, and the pencil beam module can modulate the X-rays generated by the target 53 on the end face of the anode 5 into a pencil X-ray beam, thereby forming a pencil beam. The beam X-ray tube can directly emit a pencil X-ray beam, which makes the pencil beam X-ray tube according to this embodiment have a compact structure and volume.

The position of the pencil beam module 51 facing the target 53 is provided with an electron incident hole 526, so that electrons injected from the cathode 4 can pass through the electron incident hole 526 and bombard the target 53, thereby generating X-rays.

The pencil beam module 51 includes a shield tumbler 511 , wherein the shield tumbler 511 surrounds at least one end of the anode 5 , and allows electrons emitted by the cathode 4 to reach the target 53 , and shields scattered electrons and X-rays generated by the target 53 . The above-mentioned electron entrance hole 526 may be provided on the protective drum 511 , as shown in FIG. 1 . The protective drum 511 is provided with at least one radiation exit hole 512 for modulating the X-rays generated by the target 53 to form at least one pencil-shaped X-ray.

The protective drum 511 can be made of tungsten or tungsten alloy material, which can effectively protect the X-ray radiation from the source. Part of the electrons entering the protective drum 511 through the electron incident hole 526 is scattered by the target 53 , and the scattered electrons will be shielded, blocked or absorbed by the protective drum 511 and will not scatter outside the protective drum 511 . The X-rays generated by the target 53 are emitted radially from the target 53 , and the protective drum 511 will block and shield the X-rays, and the X-rays will not leak out of the protective drum 511 . At least one ray exit hole 512 provided on the protective drum 511 allows X-rays to exit, thus forming at least one pencil-shaped X-ray. Only one ray exit hole 512 is shown in Fig. 1, however, in other embodiments, the protective drum 511 can include a plurality of ray exit holes 512, and the arrangement of these ray exit holes 512 can be set as required, for example, at a certain interval Set on the protection drum 511; it can also be discretely set on the protection drum 511.

In this embodiment, when an appropriate voltage is applied between the anode 5 and the cathode 4, electrons bombard the target 53 on one end surface of the anode 5, and the target 53 emits X-rays, so that the pencil beam module of the pencil beam X-ray tube 51 , or in other words, one or more pencil-shaped X-ray beams are emitted from a ray exit hole 512 or a plurality of ray exit holes 512 of the protective drum 511 .

In one embodiment of the present disclosure, the protective drum 511 is configured to be able to rotate around the anode 5 , so that at least one pencil-shaped X-ray beam formed through at least one radiation exit hole 512 can scan at least within a certain angle range. This is advantageous, when the shield drum 511 rotates, the pencil-shaped X-ray emitted from the shield drum 511 will scan along with the rotation of the shield drum 511 . In one embodiment, setting a collimator in front of the target 53 can more accurately limit the open angle of the X-rays emitted by the target 53 within a certain range. For clarity, FIGS. 1 and 2 do not show the collimator arranged in front of the target 53 to limit the emission range of X-rays. The opening angle of the front collimator determines the opening angle of the outgoing fan-shaped X-ray surface beam, and also determines the angular range of the pencil-shaped X-ray scanning. In one embodiment, the protective drum 511 can be further set to rotate only within a set angle range, so that the pencil-shaped X-ray beam scans a fan-shaped area.

FIG. 2 shows a schematic cross-sectional view of a pencil beam module 51 according to an embodiment of the present disclosure.

In one embodiment of the present disclosure, the pencil beam module 51 includes an armature core 515 disposed on the anode 5 close to at least one end, an armature winding 514 surrounding the armature core 515, and a corresponding armature core 515. The core 515 is set on the multiple permanent magnets on the inner wall of the protective drum 511 so that the armature winding 514 interacts with the multiple permanent magnets 513 to drive the protective drum 511 to rotate when the armature winding 514 forms a changing magnetic field. As shown in FIG. 2 , the armature core 515 is fixed on the anode 5 . For balance, the armature cores 515 are generally arranged in pairs on the anode 5 , for example, as shown in the sectional view of FIG. 2 , a pair of armature iron cores 515 are arranged on the upper side and the lower side of the anode 5 . Several armature windings 514 are wound on the armature core 515 . Corresponding to several armature windings 514 , several permanent magnets 513 are fastened to the inner wall of the protection drum 511 . The permanent magnets 513 are evenly distributed on the inner wall of the protection drum 511 . When the armature winding 514 forms a changing magnetic field, the force generated by the interaction between the armature winding 514 and the plurality of permanent magnets 513 can drive the protection drum 511 to rotate. The pencil beam module 51 also includes a bearing 520 mounted on the anode 5 that supports the guard drum 511 to allow the guard drum 511 to rotate around the anode 5 . In one embodiment, the inner ring of the bearing 520 is limited by the upper shoulder of the sleeve 521 and the inner top ring 522 , and the outer ring is limited by the flange of the protective drum 511 and the outer top ring 523 . The sleeve 521 is sleeved on the anode 52 and embedded in the inner wall of the bearing 520 . Thus, the bearing 520 is fixed on the anode 5, and the protective drum 511 is supported and fixed by the bearing 520, so that the protective drum 511 can rotate around the anode 5. At this time, the anode 5 can be regarded as an installation shaft or a rotating shaft. The protection drum 511, the sleeve 521, the outer top ring 523 and the anode 5 form a nearly closed X-ray shielding room with good performance, and the radiation protection is carried out from the source, which can reduce the radiation protection pressure of the whole equipment and use more For convenience, it can effectively shield X-rays at the same time.

In one embodiment, the pencil beam module 51 may further include a driver 517 , which is connected to an external power source and provides a variable current to the armature winding 514 . The driver 517 is placed on one side of the armature core 515 , and can be fixed on the anode 52 through a collar 516 , for example. In FIG. 2 , the right side or the right end of the anode 52 is opened with a wiring duct 524 , which is arranged to electrically connect the pencil beam module 51 to external power lines and signal lines. A sealing joint 525 is provided at the entrance of the wiring duct 524 . One end of the driver 517 is connected to the excitation winding 514 through the cable 518, and the cable 519 at the other end is connected to the inner side of the sealing joint 525 through the wiring duct 524, and can be led out of the pen-shaped X-ray tube by using an external plug joint. After being energized, the armature winding 514 is continuously commutated and energized to form a rotating magnetic field, which interacts with the magnetic field generated by the permanent magnet 513 to push the protective drum 511 to rotate around the center line of the anode 52 . The pencil-shaped X-ray beam thus modulated through the ray exit hole 512 realizes the scanning of the pencil-shaped X-ray beam through the rotational movement of the protective drum 511 . ,

The structure of the sealing joint 525 is shown in FIG. 3 , which consists of a glass stem 527 and a conductive pin 528 sintered and sealed therein. The glass stem 527 is integrated with the anode rod 52 into a closed whole through sintering and other processes; one end of the conductive guide pin 528 is connected to the wire 519, and the other end is connected to the outside of the X-ray tube. This way of leading wires ensures that the inside of the X-ray tube is in a vacuum state. In addition, other sealing and fixing styles can also be used, such as flange plate extrusion O-ring seal, etc.

In one embodiment of the present disclosure, the pencil X-ray beam emitted from the pencil beam module 51 is perpendicular to the length extension direction of the anode 5 . In another embodiment, the pencil X-ray beam emitted from the pencil beam module 51 forms an angle with the length extension direction of the anode 5 .

As shown in FIG. 4 , it is schematically shown that the pencil-shaped X-ray beam is emitted downward. When the pencil beam module 51 rotates, the pencil X-ray scans a fan-shaped area. The generation direction of the pencil X-ray beam can be set by setting the position of the ray exit hole 512 on the protective drum 511 of the pencil beam module 51, or in other words, by setting the ray exit hole 512 on the protective drum 511 of the pencil beam module 51 The position of the pencil-shaped X-ray beam and the angle of the length extension direction of the anode 5 can be set. In other words, in FIG. The angle at which the pencil X-ray beam deviates from the vertical. In one embodiment, the pencil X-ray beam is perpendicular to the length extension direction of the anode 5 , that is, the included angle between the pencil X-ray beam and the length extension direction of the anode 5 is 90 degrees. In another embodiment, the pencil X-ray beam is not perpendicular to the length extension direction of the anode 5 , that is, the included angle between the pencil X-ray beam and the length extension direction of the anode 5 is less than 90 degrees.

In other embodiments of the present disclosure, the protective drum 511 includes a plurality of radiation exit holes 512 . Multiple ray exit holes 512 are advantageous, so that each time the protective drum 511 rotates, multiple pen-shaped X-ray beams are emitted and each scans the object to be inspected, thereby increasing the detection speed. Further, these ray exit holes 512 may be arranged differently, so that the exiting pencil-shaped X-ray beams form different included angles with the length extension direction of the anode 5 . The situation of scanning each of the plurality of ray exit holes 512 is similar to the situation of scanning with one ray exit hole 512 above, and the description will not be repeated here.

An embodiment of the present disclosure also provides a backscatter detection device, including the above-mentioned pencil beam X-ray tube.

While certain embodiments of the present general patented concept have been shown and described, those of ordinary skill in the art will understand that changes may be made to these embodiments without departing from the principles and spirit of the present general patented concept. The scope is defined by the claims and their equivalents.

Claims (12)

1. A pencil beam X-ray tube, comprising: shell; An anode, at least one end of the anode is arranged in the casing, and the end surface of the at least one end is not perpendicular to the length extension direction of the anode; a target disposed on at least one end face of the anode; a cathode configured to face the target and capable of emitting electrons to the target; and The pencil beam module is configured near the at least one end of the anode to modulate the X-rays generated by the target into a pencil X-ray beam to be emitted from the pencil beam X-ray tube. 2. The pencil beam X-ray tube of claim 1 , wherein the pencil beam module includes a guard tumbler, wherein the guard tumbler surrounds at least one end of the anode and allows electrons emitted by the cathode to reach the target while shielding scattered electrons and X-rays generated by the target. 3. The pencil beam X-ray tube according to claim 2, wherein the protective drum is provided with at least one radiation exit hole for modulating the X-rays generated by the target to form at least one pencil-shaped X-ray. 4. The pencil beam X-ray tube as claimed in claim 3, wherein the shield tumbler is configured to be rotatable around said anode, so that at least one pencil X-ray beam formed through at least one ray exit aperture can be scanned within a certain angular range . 5. The pencil beam X-ray tube as claimed in claim 4, wherein the pencil beam module comprises an armature core disposed on the anode near at least one end and an armature winding wound around the armature core, and a corresponding armature The armature core is arranged on a plurality of permanent magnets on the inner wall of the protection drum, so that when the armature winding forms a changing magnetic field, the armature winding interacts with the plurality of permanent magnets to drive the protection drum to rotate. 6. The pencil beam X-ray tube of claim 5, wherein the pencil beam module further comprises a driver connected to an external power source and providing a varying current to the armature winding. 7. The pencil beam X-ray tube of claim 4, wherein the pencil beam module includes a bearing disposed on the anode, the bearing supporting the guard tumbler to allow the guard tumbler to rotate about the anode. 8. The pencil beam X-ray tube according to claim 1, wherein the anode comprises a wiring duct for arranging power lines and signal lines electrically connecting the pencil beam module to the outside. 9. The pencil beam X-ray tube according to claim 1, wherein the pencil X-ray beam emitted from the pencil beam module is perpendicular to the length extension direction of the anode. 10. The pencil beam X-ray tube of claim 1, wherein the pencil X-ray beam emerging from the pencil beam module forms an angle with respect to the direction in which the length of the anode extends. 11. The pencil beam X-ray tube as claimed in claim 1, wherein the shield tumbler is made of tungsten or tungsten alloy material. 12. A backscatter detection device comprising the pencil beam X-ray tube according to any one of claims 1-11.