This application claims priority to Chinese Patent App. No. 201710856486.2, titled “X-RAY CONVERSION TARGET”, which was filed on Sep. 19, 2017, and which is hereby incorporated by reference in its entirety.
The disclosed technology relates to the field of X-ray conversion, and in particular, to an X-ray conversion target and X-ray generator.
With continuous improvement of electron accelerator technologies, accelerators are widely being used for various applications in more and more industries. For example, high-energy electrons accelerated by the accelerator may be used to modify a product. Examples of using accelerators can include foods being irradiated and sterilized in the food industry, X-ray irradiation breeding, X-ray stimulated increase in production and X-ray irradiation for pest control in agriculture, and medical imaging and medical treatment being performed in medical industry.
For a high-power accelerator for irradiation, it is necessary to dissipate heat of a target material, otherwise the target material may be melted if the heat of the target material could not be removed rapidly. Meanwhile, heat dissipation effect directly influences a useful life of a conversion target and a work efficiency of an accelerating tube.
According to an aspect of the disclosed technology, there is provided an X-ray conversion target, comprising a target body and a target part disposed within the target body, the target part having a first face configured to produce X-rays;
wherein, the X-ray conversion target further comprises a cooling passage having a side wall, at least a part of the side wall being constituted by a portion of the target part.
In one embodiment, the cooling passage comprises a cooling groove located in a second face of the target part, the second face and the first face being two faces of the target part facing away from each other; and
the cooling groove is defined by the second face together with a first ridge and a second ridge, which are arranged opposite to each other and extend along an edge of the second face of the target part respectively.
In one embodiment, the cooling passage comprises an annular groove provided in the target body at a side of the target part, provided within the target body.
In one embodiment, the X-ray conversion target further comprises a cooling lateral portion located at a side of the target part, the cooling lateral portion defining an interior space of the cooling lateral portion in which the X-rays produced by the target part propagate.
In one embodiment, the target body comprises a target body outer side portion defining an interior space of the target body; and the annular groove is defined by the target body outer side portion and the cooling lateral portion of the target part.
In one embodiment, the target body outer side portion and the cooling lateral portion of the target part are connected with each other by a connection part, which defines, together with the target body outer side portion and the cooling lateral portion of the target part, the annular groove; and the connection part comprises a fluid inlet adjacent to a first end of the target part and a fluid outlet adjacent to a second end of the target part opposite to the first end.
In one embodiment, a top face of the target body outer side portion is located in a same plane as top faces of the first ridge and the second ridge.
In one embodiment, the X-ray conversion target further comprises a cover plate arranged on the top face of the target body outer side portion and the top faces of the first ridge and the second ridge.
In one embodiment, the target part includes copper.
In one embodiment, the target part includes gold on a surface of the copper.
In one embodiment, the X-ray conversion target further comprises a passage support plate extending continuously from the target body outer side portion and defining an emission passage for the X-rays produced by the target part.
In one embodiment, the X-ray conversion target further comprises a passage support plate extending from the target body outer side portion and defining an emission passage for the X-rays produced by the target part.
In one embodiment, the X-ray conversion target further comprises support plate fins arranged on an outer side of the passage support plate and configured to dissipate heat from the passage support plate.
In one embodiment, the cooling lateral portion at the side of the target part, the first ridge and the second ridge are formed into a one-piece structure.
In one embodiment, the cooling lateral portion at the side of the target part, the first ridge, the second ridge and the target body outer side portion are formed into a one-piece structure.
In one embodiment, the first ridge and the second ridge each have a thickness greater than 5 mm, with respect to the second face.
According to an aspect of the disclosed technology, there is provided an X-ray generator comprising the above described X-ray conversion target.
In one embodiment, the X-ray generator includes an electron accelerator configured to provide accelerated electrons.
In one embodiment, the X-ray generator includes a coolant supply device configured to supply a coolant for circulation.
In one embodiment, the X-ray generator includes a heat sink configured to cool the coolant for circulation.
Although various modification and alternatives may be made to the disclosed technology, exemplary embodiments of the disclosed technology will be illustrated for example in the drawings and will be described in detail herein. It will be understood, however, that the accompanying drawings and the detailed description are not intended to limit the disclosed technology to specific forms disclosed, rather, are intended to cover all modifications, equivalents and alternatives falling with spirit and scope of the disclosed technology defined in appended claims. The drawings are only schematic and thus may not be drawn to scale.
Embodiments of the disclosed technology will be described with reference to the drawings.
As shown in
In a working state, a high-energy electron beam is perpendicularly incident to the first face of the target part 5, so that the target part 5, which may be formed by, for example, a copper material, produces X-rays, while parts of high-energy electrons become back bombardment electrons. The first face may be a substantially planar surface. Bombardment of the high-energy electrons causes an increased temperature of the target part 5. A portion of the target part 5 constitutes the side wall of the cooling passage such that heat generated by the target part 5 may be directly transferred to the cooling passage and carried away by fluid in the cooling passage, thereby the temperature of the target part 5 will not quickly rise. The fluid in the cooling passage may be a liquid, for example, water having a large specific heat. Since the copper has a good heat conductivity, the heat generated by the target part 5 may be quickly transferred to a cooling medium in the cooling passage.
In one embodiment of the disclosed technology, as shown in
In one embodiment, the cooling groove 1 is defined by the second face together with a first ridge 21 and a second ridge 22, which are arranged opposite to each other and extend along an edge of the second face of the target part 5 respectively. In the embodiment shown in
In another embodiment, a third ridge, a four ridge or more ridges may be provided on the second face, as heat dissipation elements, for increasing contact area of the second face of the target part 5 with the cooling medium to improve heat dissipation ability.
In one embodiment, the cooling passage further comprises an annular groove 3 located at a side of the target part 5 and around the target part 5.
In one embodiment, the X-ray conversion target further comprises a cooling lateral portion 2 located at a side of the target part 5, and the cooling lateral portion 2 defines an interior space of the cooling lateral portion 2, in which the X-rays produced by the target part 5 propagates. In other words, an extending direction of the cooling lateral portion 2 is substantially the same as an emitting direction of the X-rays produced by the target part 5, and is opposite to a movement direction of the high-energy electron beam bombarding towards the target part 5. The movement direction of the high-energy electron beam is generally indicated by an arrow 10 in
In one embodiment, the cooling lateral portion 2 at the side of the target part 5, the first ridge 21 and the second ridge 22 are formed into a one-piece structure. The one-piece structure is advantageous in that heat generated by the target part 5 may be quickly transferred to a low-temperature region of the target part 5.
In one embodiment, the target body comprises a target body outer side portion 6 defining an interior space of the target body. The target body outer side portion 6 together with the cooling lateral portion 2 of the target part 5 defines the annular groove 3. In other words, the target body outer side portion 6 forms an outer portion of the annular groove 3, while the cooling lateral portion 2 of the target part 5 forms an inner portion of the annular groove 3, and the annular groove 3 is formed between the target body outer side portion 6 and the cooling lateral portion 2 of the target part 5. A cooling medium may flow in the annular groove 3 so as to bring away heat of the cooling lateral portion 2 of the target part 5, thereby reducing temperature of the cooling lateral portion 2 of the target part 5.
In one embodiment, the cooling lateral portion 2 at the side of the target part 5, the first ridge 21, the second ridge 22 and the target body outer side portion 6 are formed into a one-piece structure. The one-piece structure is advantageous in that heat generated by the target part 5 may be quickly transferred to a low temperature region of the target part 5.
In one embodiment, a top face of the target body outer side portion 6 is located in a same plane as top faces of the first ridge 21 and the second ridge 22. The X-ray conversion target may further comprise a cover plate 7 arranged on the top faces of the target body outer side portion 6 and the top faces of the first ridge 21 and the second ridge 22.
In this embodiment, when the cover plate 7 covers the top faces of the target body outer side portion 6 and the top faces of the first ridge 21 and the second ridge 22, it will be understood that since the top face of the target body outer side portion 6 is located in the same plane as the top faces of the first ridge 21 and the second ridge 22, the cooling groove 1 located between the first ridge 21 and the second ridge 22 are separated from the annular groove 3 by the first ridge 21 and the second ridge 22, while the annular groove 3 is divided into two parts by the first ridge 21 and the second ridge 22. For example, and as shown in
The target body outer side portion 6 and the cooling lateral portion 2 of the target part 5 are connected with each other by a connection part, which defines, together with the target body outer side portion 6 and the cooling lateral portion 2 of the target part 5, the annular groove 3. In this case, as shown in
In this embodiment, the connection part comprises a fluid inlet 8 adjacent to a first end of the target part 5 and a fluid outlet 9 adjacent to a second end of the target part 5 opposite to the first end. A cooling medium such as water flows into the annular groove 3 through the fluid inlet 8. Referring to
In another embodiment of the disclosed technology, the second face of the target part 5 is further provided with a third ridge and even a fourth ridge, thereby providing a further heat dissipation part in contact with the cooling medium. A top face of the third ridge or more ridges may be not located in a same plane as the top face of the first ridge 21. A plurality of ridges may be used as radiating fins to improve heat dissipation ability.
In one embodiment, the top face of the third ridge or more ridges may be located in a same plane as the top faces of the first ridge 21 and the second ridge 22. In such a case, the cooling groove 1 is divided into a plurality of sub cooling grooves 1, thereby not only arrangement of a plurality of ridges may improve heat dissipation effect, but also the cooling effect may be greatly improved due to the following fact: a cross sectional area of the cooling groove 1 is reduced (occupied by the plurality of ridges), thus a flow velocity of the cooling medium will be increased for a constant flow rate of the cooling medium, and a contact area of the ridges with the cooling medium is further increased, that is, an indirect contact area of the target part 5 with the cooling medium is increased. For this case, it is important that the target part 5 is made of a heat conductive material such as copper, because the copper can transfer heat generated by the target part 5 to its back face (second face) quickly, and also to the cooling lateral portion 2 of the target part 5.
In one embodiment, gold is provided on a surface of the target part 5. For example, a gold layer 4 is provided on a surface of a copper target part 5 so as to form a composite target part 5, which is advantageous because the composite target part 5 may ensure obtaining a higher dosage rate of production of X-rays under a high-energy electron beam of a constant energy. For example, a portion of the target part 5 generating the X-rays may be, for example, a composite target formed by covering a gold layer 4 having a thickness of lmm on an oxygen-free copper having a thickness of 4 mm. This composite target can provide a larger dosage rate of production of X-rays. This composite target has a length of 80 mm, which length may cooperate with a scanning magnet to generate stripe-shaped X-rays, thereby satisfying different requirements for shape of the X-rays.
In this embodiment, the cooling lateral portion 2 of the target part 5 defines the interior space of the cooling lateral portion 2, so that when the target part 5 is bombarded by the high-energy electron beam, X-rays generated by the target part 5 propagates within the interior space of the cooling lateral portion 2, while some high-energy electrons form back-bombardment electrons which are reflected to go away from the target part 5.
In one embodiment of the disclosed technology, a thickness of the outer side portion of the target body may be, for example, 4 mm, a thickness of the cover plate 7 may be, for example, 1.5 mm, and the cover plate 7 may be a stainless steel plate. The cover plate 7 may function to fix and seal the target.
In one embodiment of the disclosed technology, as shown in
During actual operation, when the high-energy electron beam bombards the target part 5, the cooling medium, for example water, is injected through the fluid inlet 8, and is discharged from the fluid outlet 9, so that the temperature of the target part 5 may be controlled in a better way. An injection amount of the cooling medium may be determined based on energy of the high-energy electron beam.
Embodiments of the disclosed technology further provide an X-ray generator. The X-ray generator may include the above described X-ray conversion target. The X-ray generator may further include an electron accelerator configured to provide accelerated electrons. The X-ray generator may further include a coolant supply device configured to supply a coolant for circulation. In order to cool the coolant that is heated during circulation, the X-ray generator may further include a heat sink configured to cool the coolant for circulation.
Although various exemplary embodiments according to the general concepts of the disclosed technology have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications can be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.
Number | Date | Country | Kind |
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201710856486.2 | Sep 2017 | CN | national |