X-ray source

Abstract

The X-ray source comprises a shell which is arranged on a CT rotating disc and connected with a ground wire, an annular cavity is formed between the shell and the CT rotating disc, and a cathode part and an anode part which are matched with each other are arranged in the annular cavity; the anode part comprises an annular substrate and a target surface arranged on the substrate, the substrate is arranged on the shell through an insulated supporting part, positive high voltage is introduced through a connecting part, and the substrate can freely slide on the supporting part and is provided with a balancing weight; a gap is formed between the cathode part and the anode part, a lamp filament close to the target surface is assembled on the power supply support, the power supply support and the CT rotating disc are conductive, and the CT rotating disc is connected with a power supply through a power supply brush. According to the X-ray source, the operation mode that the anode is fixed and the cathode is rotated is adopted to generate X-rays, heat in the X-ray generation process is evenly distributed on the target surface of the anode, the heat on the target surface is rapidly dissipated through the additionally arranged substrate, and then the thermal capacity and the power of the X-ray source are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical instruments, and in particular to an X-ray source. Background Art

[0002] An X-ray source is a device that generates X-rays. It includes two electrodes, an anode and a cathode. The cathode contains a filament that emits electrons. When the filament is heated, free electrons are generated. The free electrons are accelerated by the electric field between the anode and the cathode to become high-energy electrons. The high-energy electrons collide with the anode target surface at high speed, causing the movement of the high-energy electrons to be suddenly blocked. A small part of their kinetic energy is converted into radiation energy to form X-rays. Common X-ray tubes are divided into rotating anode X-ray tubes and fixed anode X-ray tubes according to the type of anode.

[0003] In a fixed anode X-ray tube, the target surface of the anode is stationary and does not move. The electron flow generated by the cathode always bombards the same position on the target surface, and the generated heat radiation is conducted out through the anode handle. Since the high-energy electron flow continuously bombards a very small area of ​​the target surface, it is limited by the thermal power per unit area of ​​the anode, making the instantaneous power and average power of the fixed anode X-ray light source relatively low; in a rotating anode X-ray tube, the target surface of the anode rotates, and the electron flow generated by the cathode bombards the rotating target surface at high speed to generate X-rays. The heat generated is evenly distributed on the rotating anode. Because the area bombarded by the electron flow increases due to the rotation of the anode, the heat distribution area is increased, so the power of the X-ray tube is effectively improved, making it possible to reduce the actual focus and appropriately reduce the target angle to reduce the effective focus. However, due to the overly simple structure of the anode, its heat capacity is relatively low, which in turn limits the power of the X-ray light source, and therefore places excessively high requirements on heat dissipation. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an X-ray source.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An X-ray source comprises a shell which is arranged on a CT rotating disk and connected to a ground wire, and an annular cavity is formed between the shell and the CT rotating disk, wherein a cathode part and an anode part which cooperate with each other are arranged in the annular cavity; the anode part comprises a circular ring-shaped substrate and a target surface on the substrate, the substrate is arranged on the shell through an insulating support part, and a positive high voltage is introduced through a connecting part, the substrate can slide freely on the support part, and a counterweight block is also installed on the substrate, and the target surface covers the movement track of the focus during X-ray CT tomography scanning; there is a gap between the cathode part and the anode part, and the source comprises a power supply bracket arranged on the CT rotating disk, a filament close to the target surface is installed on the power supply bracket, the power supply bracket is electrically conductive with the CT rotating disk, and the CT rotating disk is connected to the power supply through a power supply brush.

[0007] Preferably, there are multiple cathode parts, and the multiple cathode parts are evenly arranged on the CT rotating disk.

[0008] Preferably, the filament is made of wound tungsten wire.

[0009] Preferably, the cathode part further comprises a focusing cover which is arranged on the power supply bracket and covers the filament, and one end of the focusing cover corresponding to the target surface passes through.

[0010] Preferably, the annular substrate is made of copper, and the target surface is made of rhenium-tungsten alloy.

[0011] Furthermore, the above-mentioned X-ray source also includes a driving mechanism for driving the anode part to rotate, and the rotation direction of the anode part is opposite to the rotation direction of the CT rotating disk. Specifically, the supporting part includes a fixed head, the fixed head is provided with an assembly hole for the substrate and the target surface to pass through at the same time, the assembly hole is provided with a limit pin, the substrate is provided with a limit slot, and the limit pin is slidably connected to the limit slot; the connecting part is composed of an insulating seat and a power supply brush, the power supply brush is in contact with the limit slot, the insulating seat is installed on the outer shell, and the driving mechanism includes a motor arranged on the outer shell, a gear is provided on the driving shaft of the motor, a tooth groove is provided on the peripheral side of the substrate, and the gear is meshed with the tooth groove.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. The present invention generates X-rays by fixing the anode and rotating the cathode, so that the heat generated during the X-ray generation process is evenly distributed on the target surface of the anode, and the heat on the target surface is quickly dissipated through the added substrate, thereby increasing the heat capacity of the X-ray source and increasing the power of the X-ray source.

[0014] 2. The anode part is driven to rotate in the opposite direction of the cathode part through an additional driving mechanism, so that the cathode part rotates faster than the anode part, so that the heat generated during the X-ray generation process can be more evenly distributed on the target surface of the anode, thereby allowing the X-ray source disclosed in the present invention to use a larger tube current. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the present invention after being cut open along the circumference of the annular cavity;

[0016] Figure 2 It is a schematic diagram of the internal structure of the annular cavity of the present invention;

[0017] Figure 3 It is a schematic diagram of the driving mechanism and the anode part in the present invention.

[0018] Figure symbols: 1. driving mechanism, 11. motor, 12. gear, 13. tooth groove, 2. housing, 3. CT rotating disk, 4. cathode part, 41. power supply bracket, 42. filament, 5. anode part, 51. substrate, 52. target surface, 53. supporting part, 531. fixing head, 532. assembly hole, 533. limiting pin, 534. limiting slide groove, 54, connecting part, 541. insulating seat, 542. power supply brush, 55. counterweight. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0020] Example 1

[0021] like Figure 1-3 An X-ray source shown in the figure includes a housing 2 which is arranged on a CT rotating disk 3 and connected to a ground wire, and an annular cavity is formed between the housing 2 and the CT rotating disk 3, and a cathode portion 4 and an anode portion 5 which cooperate with each other are arranged in the annular cavity; the anode portion 5 includes a circular ring-shaped substrate 51 and a target surface 52 on the substrate 51, the substrate 51 is arranged on the housing 2 through an insulating support portion 53, and a positive high voltage is introduced through a connecting portion 54, the substrate 51 can slide freely on the support portion 53, and a counterweight block 55 is also installed on the substrate 51, and the target surface 52 covers the movement trajectory of the focus during X-ray CT tomography scanning; there is a gap between the cathode portion 4 and the anode portion 5, including a cathode portion 4 and an anode portion 5 arranged on the CT rotating disk 3 The power supply bracket 41 is mounted on the CT rotating disk 3, and a filament 42 close to the target surface 52 is mounted on the power supply bracket 41. The power supply bracket 41 is electrically conductive with the CT rotating disk 3, and the CT rotating disk 3 is powered by a power supply brush. Specifically, the filament 42 is made of tungsten wire, and the substrate 51 and the target surface 52 are respectively made of copper and rhenium tungsten alloy, so that the substrate 51 and the target surface 52 can be well thermally and electrically connected. The insulating support portion 53 ensures that there is no discharge between the anode portion and the shell 2. After the connecting portion 54, the filament 42 and the shell 2 are energized, the cathode portion 4 emits thermal electrons, and the emitted thermal electrons are accelerated to bombard the target surface 52 under the action of the electric field formed by the cathode portion 4 and the anode portion 5 to generate X-rays.

[0022] Specifically, during the CT scanning process, the cathode part 4 in operation rotates driven by the CT rotating disk 3, and the position of the anode part 5 does not move. As the cathode part 4 rotates, high-energy electrons bombard different parts of the target surface 52, so that the generated heat is evenly distributed on the target surface 52 and transferred to the copper substrate 51. The large heat capacity of copper is used to dissipate the heat deposited on the anode part 5 through thermal radiation. In the process of the operation of the CT rotating disk 3, since the substrate 51 can slide freely on the support part 53, the counterweight block 55 installed on the substrate 51 does not rotate with the support part 53 under the action of gravity, so that the substrate 51 rotates in the opposite direction relative to the position of the cathode part 4, thereby realizing the operation mode of fixing the anode part 5 and rotating the cathode part 1.

[0023] In some embodiments, there are multiple cathode parts 4 , and the multiple cathode parts 4 are evenly arranged on the CT rotating disk 3 .

[0024] In some embodiments, the cathode portion 4 also includes a focusing cover disposed on the power supply bracket 41 and covering the filament 42. The focusing cover passes through one end corresponding to the target surface 52, thereby forming a channel for constraining the movement of high-energy electrons, thereby making it more conducive for high-energy electrons to move from the vicinity of the filament 42 of the cathode portion 4 to the target surface 52 of the anode portion 5.

[0025] Example 2

[0026] The X-ray source further includes a driving mechanism 1 for driving the anode portion 5 to rotate, and the rotation direction of the anode portion 5 is opposite to the rotation direction of the CT rotating disk 3. The additional driving mechanism 1 drives the anode portion 5 to rotate in the opposite direction of the cathode portion 4, thereby making the cathode portion 4 rotate faster than the anode portion 5, so that the heat generated during the X-ray generation process can be more evenly distributed on the target surface of the anode, thereby making the X-ray source use a larger tube current. Specifically, the support portion 53 includes a fixed head 531, and a fixed head 531 is provided with a substrate 51 and a target The target surface 52 also passes through the assembly hole 532, the assembly hole 532 is provided with a limit pin 533, the substrate 51 is provided with a limit slot 534, and the limit pin 533 is slidably connected with the limit slot 534, so that the substrate 51 and the target surface 52 can rotate on the fixed head 531; the above-mentioned connecting part 54 is composed of an insulating seat 541 and a power supply brush 542, the power supply brush 542 is in contact with the limit slot 534, and the insulating seat 541 is installed on the housing 2, so that the connecting part 54 can stably conduct electricity with the substrate 51 during the rotation of the substrate 51, thereby ensuring that the anode part 5 can operate normally;

[0027] In some embodiments, the driving mechanism 1 includes a motor 11 disposed on the outer casing 2, a gear 12 is disposed on the driving shaft of the motor 11, a tooth groove 13 is opened on the peripheral side of the substrate 51, and the gear 12 is meshed with the tooth groove 13. When the motor 11 is running, it can drive the anode part 5 to rotate in the opposite direction of the cathode part 4.

[0028] In some embodiments, the driving mechanism 1 is a direct-drive motor. Specifically, a coil is wound on the support portion 53 as the stator of the direct-drive motor, and a permanent magnet is arranged on the annular substrate 51 as the rotor of the direct-drive motor. When the stator is connected to the current, a traveling wave magnetic field is formed in the assembly hole 532. The permanent magnet of the rotor moves relative to the stator under the action of the traveling wave magnetic field. Under the limitation of the limiting pin 533 and the limiting groove 534, the substrate 51 is able to rotate, thereby realizing the rotation of the anode portion 5, and the rotation direction is controlled by the direction of the current connected to the stator.

[0029] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. An X-ray source, characterized in that: It comprises a housing (2) which is arranged on a CT rotating disk (3) and connected to a ground wire, and an annular cavity is formed between the housing (2) and the CT rotating disk (3), wherein a cathode portion (4) and an anode portion (5) which cooperate with each other are arranged in the annular cavity; The anode part (5) comprises a circular substrate (51) and a target surface (52) on the substrate (51); the substrate (51) is arranged on the housing (2) via an insulating support part (53), and a positive high voltage is introduced via a connecting part (54); the substrate (51) can slide freely on the support part (53), and a counterweight (55) is also mounted on the substrate (51); the target surface (52) covers the movement trajectory of the focus during X-ray CT tomography; There is a gap between the cathode part (4) and the anode part (5), and the cathode part (4) comprises a power supply bracket (41) arranged on the CT rotating disk (3), and a filament (42) close to the target surface (52) is mounted on the power supply bracket (41); The power supply bracket (41) is electrically conductive with the CT rotating disk (3), and the CT rotating disk (3) is connected to power via a power supply brush.

2. The X-ray source according to claim 1, characterized in that The number of the cathode parts (4) is plural, and the plurality of cathode parts (4) are evenly arranged on the CT rotating disk (3).

3. The X-ray source according to claim 2, characterized in that The filament (42) is made of tungsten wire.

4. The X-ray source according to claim 3, characterized in that The cathode part (4) also includes a focusing cover which is arranged on the power supply support (41) and covers the filament (42), and one end of the focusing cover corresponding to the target surface (52) passes through.

5. The X-ray source according to any one of claims 1 to 4, characterized in that: The annular substrate (51) is made of copper, and the target surface (52) is made of rhenium-tungsten alloy.

6. The X-ray source according to claim 5, characterized in that It also comprises a driving mechanism (1) for driving the anode part (5) to rotate, and the rotation direction of the anode part (5) is opposite to the rotation direction of the CT rotating disk (3).

7. The X-ray source according to claim 6, characterized in that The support portion (53) comprises a fixed head (531), the fixed head (531) is provided with an assembly hole (532) for the substrate (51) and the target surface (52) to pass through simultaneously, the assembly hole (532) is provided with a limit pin (533), the substrate (51) is provided with a limit slide groove (534), and the limit pin (533) is slidably connected to the limit slide groove (534); The connecting portion (54) is composed of an insulating seat (541) and a power supply brush (542), the power supply brush (542) is in contact with the limiting sliding groove (534), and the insulating seat (541) is installed on the housing (2).

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