A small eccentric self-rotating reaction target device
By designing a small eccentric rotating reaction target device, the high-speed rotation of the reaction target is achieved by using a magnetohydrodynamic seal and transmission device, which solves the problem of high heat flux density, reduces the heat flux density of the reaction target, increases the usable area, extends the service life, and reduces costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA INSTITUTE OF ATOMIC ENERGY
- Filing Date
- 2022-11-04
- Publication Date
- 2026-06-05
AI Technical Summary
Existing reaction target devices are difficult to effectively reduce heat flux density when facing high heat flux density beams, and existing devices are costly and not universal, making it difficult to adapt to beams of different energies and powers.
A small eccentric rotating reaction target device is designed. By combining a magnetohydrodynamic sealing device, a transmission device, a water distributor and a circulating water pipe, the high-speed rotation of the reaction target is achieved, the beam spot is diffused and the heat flux density is reduced, while the positional relationship between the beam and the detector remains unchanged.
It effectively reduces the maximum heat flux density of the reaction target, increases the usable area of the reaction target, extends the service life, reduces the cost of the device, and adapts to beams of different energies and powers.
Smart Images
Figure CN115902993B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of reaction targets, and particularly relates to a small eccentric self-rotating reaction target device. Background Art
[0002] A 400 kV high-current accelerator can provide a proton beam current of 10 mA or a He + beam current of 5 mA. The beam spot size is about 10 mm (±2σ) in diameter, and the beam current is generally Gaussian distributed. As Figure 1 shown, the central heat flux density of the heat flux density distribution when the total power is 1 kW can reach 2.5 kW / cm 2 . For some experiments carried out on this accelerator, the reaction target may be difficult to withstand such a high heat flux density. Therefore, it is necessary to find a way to reduce the maximum heat flux density of the beam.
[0003] Currently, there are roughly two typical methods internationally used to reduce the heat flux density of the beam:
[0004] The first is to increase the beam spot area: The beam sweeping device supporting the commercial accelerator of the Dutch High Voltage Company can expand the beam spot from 10 mm in diameter to 5 cm in diameter. Naturally, the expansion of the beam spot effectively reduces the heat flux density; there is also a design method that uses a rotating magnetic field or an alternating magnetic field to expand the beam spot. In both cases, it is necessary to adjust the corresponding high voltage or magnetic field intensity according to the beam energy to control the beam spot.
[0005] The second is to increase the beam hitting area of the reaction target: The high-current Faraday cup on the ADS device of the Institute of Modern Physics, Chinese Academy of Sciences is made into a conical shape, increasing the beam receiving surface several times compared to the beam spot; the projectile fragmentation reaction targets used on the radioactive beam line mostly adopt rotating reaction targets, such as the FIAR in Germany, EURIAOL in Europe, FRIB in the United States, RIPS in Japan and other devices; the high-power neutron conversion target in Spain (NIM A 724(2013)34), a large turntable structure, converts between vacuum and atmosphere; the pulling belt device for measuring decay or irradiation equipment, etc. These designs effectively increase the receiving surface of the beam on the reaction target, thereby achieving the effect of reducing the heat flux density.
[0006] All of the above devices are designed for specific equipment and uses. The equipment is huge and not universal for beam currents of different energies and powers. Summary of the Invention
[0007] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a small eccentric self-rotating reaction target device, which reduces the heat flux density received by the reaction target through a small rotating reaction target, has a low cost and strong practicability.
[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a small eccentric rotating reaction target device, the device comprising a magnetic fluid sealing device, a transmission device, a water distributor, an internal pipeline of the reaction target, a circulating water pipeline, and a reaction target. The front surface of the reaction target is vacuum-sealed with the internal pipeline of the reaction target through a sealing ring. One side of the circulating water pipe wall is connected to the internal slider of the water distributor, and the other side is sealed by a rear cover. The water passage of the water distributor, the water passage of the circulating water pipeline, and the cavity between the back of the reaction target and the rear cover are interconnected to form a circulating water passage. The magnetic fluid sealing device is connected to the beam pipeline adapter flange to achieve a rotational seal between the device and the beam pipeline adapter flange. The transmission device is connected to the magnetic fluid sealing device, the internal slider of the water distributor, the internal pipeline of the reaction target, and the circulating water pipeline. The transmission device is connected to a motor through a synchronous belt to provide rotational power to the reaction target. The outer shell of the water distributor is connected to inlet and outlet water pipes, and the internal water passage of the water distributor is connected to the circulating water pipeline to provide circulating water to the rotating circulating water pipeline.
[0009] Furthermore, a certain cavity is maintained between the rear cover and the reaction target to ensure the flow of circulating water.
[0010] Furthermore, the water distributor has a ring structure, with an inlet and an outlet on the upper and lower sides of the outer shell of the water distributor, respectively. An internal slider is provided inside the water distributor, and circulating water loops connecting the inlet and outlet are respectively located on the upper and lower sides of the slider.
[0011] Furthermore, three rotating sealing rings are installed inside the water distributor.
[0012] Furthermore, the magnetic fluid sealing device is provided with a magnetic fluid sealing shaft, and a beam pipe transition flange is provided on the outside of the magnetic fluid sealing shaft. The center position of the beam pipe transition flange is the beam target position, and the center of the inner wall of the beam pipe transition flange is the center of the reaction target. The beam target position corresponds to the center of the reaction target.
[0013] Furthermore, the eccentricity of the reaction target is adjusted by modifying the fixing bolt hole position of the beam pipe adapter flange. The eccentricity of the reaction target is the distance between the beam hitting position and the center of the reaction target.
[0014] Furthermore, the transmission device includes a reaction target transmission wheel, a motor, a synchronous belt, and a motor synchronous pulley. The reaction target and the motor are fixed on the same fixed bracket. The synchronous belt is connected to the motor synchronous pulley, and the synchronous belt is connected to the reaction target transmission wheel to provide rotational power. The reaction target transmission wheel drives the magnetohydrodynamic sealing shaft, the internal slider of the water distributor, the internal pipe of the reaction target, the circulating water pipe, and the reaction target to rotate at high speed.
[0015] Furthermore, the water distributor housing is fixed stationary on the fixed bracket, and the circulating water flows into the rotary water inlet from the water inlet, flows through the back of the reaction target, flows back from the other end of the rotary water inlet, and flows out from the water outlet.
[0016] Furthermore, the outer side of the beam pipe adapter flange is connected to the accelerator front-end pipe.
[0017] Furthermore, the length of the reaction target cannot exceed the focusing length of the accelerator at the end of the pipe, and the outer diameter of the reaction target device entering the detector must not be greater than the inner diameter of the detector.
[0018] The beneficial technical effects of this invention are as follows: Compared with scanning devices costing hundreds of thousands of dollars, the small eccentric rotating reactive target device disclosed in this invention significantly reduces the cost of the device, effectively reduces the maximum heat flux density that the reactive target can withstand, and does not change the relative positional relationship between the beam spot and the detector, making it easier to calibrate the efficiency of the experiment, thereby ensuring the stability and reliability of the experiment. Furthermore, even if the reactive target itself can withstand the heat flux density of the beam, the reactive target in the small eccentric rotating reactive target device disclosed in this invention can still be used. Even if the reactive target itself is operating at a low speed, it is equivalent to increasing the beam's target area, effectively improving the utilization rate of the reactive target, and extending the service life of the reactive target. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the heat flux density distribution of a beam with a total power of 1kW in the prior art;
[0020] Figure 2 A schematic diagram of the reaction target process in a small eccentrically rotating reaction target device according to an embodiment of the present invention, which employs eccentric beam bombardment of the reaction target.
[0021] Figure 3 A schematic diagram of the heat flux density distribution of the reaction target in a small eccentric rotating reaction target device described in this embodiment of the invention, which uses a 1kW beam with a diameter of 10 mm to bombard the target with an eccentric 7.5 mm diameter beam.
[0022] Figure 4 This is a schematic diagram of a small eccentric rotating reaction target device according to an embodiment of the present invention;
[0023] Figure 5 This is a side view of a small eccentric rotating reaction target device according to an embodiment of the present invention;
[0024] Figure 6 This is a front view of a small eccentric rotating reaction target device according to an embodiment of the present invention;
[0025] Figure 7This is a schematic cross-sectional view of the central rotating structure of the water separator in a small eccentric self-rotating reaction target device according to an embodiment of the present invention.
[0026] Wherein: 1-beam spot, 2-beam sweep area, 3-magnetic fluid sealing device, 4-transmission device, 5-water distributor, 6-internal pipe of reaction target, 7-circulating water pipe, 8-reaction target, 9-rear cover, 11-water inlet, 12-rotary water inlet, 13-water outlet, 14-reaction target transmission wheel, 15-magnetic fluid sealing shaft, 16-beam pipe adapter flange, 17-motor, 18-synchronous belt, 19-motor synchronous pulley, 20-fixed bracket, 21-inner wall of adapter flange, 22-inner wall of internal pipe of reaction target, 23-water distributor slider, 24-water distributor shell, 25-rotating sealing ring. Detailed Implementation
[0027] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.
[0028] Example 1
[0029] This invention provides a small-scale eccentrically rotating reaction target device. The device includes a reaction target. Due to the limitations of the laboratory and accelerator pipeline in horizontal space, the length of the reaction target cannot exceed the focusing length of the accelerator at the end of the pipeline. In this embodiment, the length of the reaction target cannot exceed 1 meter to avoid affecting beam focusing. Simultaneously, the matching BGO detector array or neutron detector array must be considered. The outer diameter of the portion of the reaction target device entering the detector must not exceed the inner diameter of the detector. In this embodiment, the outer diameter of this portion of the reaction target device entering the detector must not exceed 8 centimeters.
[0030] The reaction target is rotated about an axis along the beam direction, and the beam bombards an off-center position. When the reaction target rotates fast enough, the beam spot effectively diffuses into a ring-shaped region, such as... Figure 2 As shown, beam spot 1 is located in the beam-scanned region 2, and the arrow indicates the direction of rotation. Simulations show that when a 1kW beam with a diameter of 10mm bombards such a reaction target with an eccentricity of 7.5mm, its heat flux density will become as follows: Figure 3 The distribution shown is consistent with Figure 1 Compared with the heat flux density distribution in the present invention, it can be seen that the maximum heat flux density is reduced by about 7 times. Therefore, the small eccentric rotating reaction target device provided in this embodiment of the invention can effectively reduce the maximum heat flux density borne by the reaction target, while increasing the effective usable area of the reaction target and increasing the service life of the reaction target.
[0031] The main problem to be solved in the process is the cooling water circulation under rotation. Therefore, the small eccentric rotating reaction target device provided in this embodiment of the invention adopts a front-end water inlet and outlet structure, and the cooling water rotates with the reaction target.
[0032] like Figure 4 As shown, the small eccentric rotating reaction target device provided in this embodiment of the invention includes a magnetic fluid sealing device 3, a transmission device 4, a water distributor 5, an internal pipe 6 of the reaction target, a circulating water pipe 7, and a reaction target 8. The front surface of the reaction target 8 is vacuum-sealed with the internal pipe 6 of the reaction target through a sealing ring. One side of the circulating water pipe 7 is connected to the internal slider of the water distributor 5 and is sealed by the magnetic fluid sealing device 3. The other side of the circulating water pipe is sealed by a rear cover 9. The water path of the water distributor 5, the water path of the circulating water pipe 7, and the cavity between the back of the reaction target 8 and the rear cover 9 are connected to form a circulating water path. A certain cavity is maintained between the rear cover 9 and the reaction target 8 to ensure the circulation of circulating water. At the same time, a water seal is achieved between the sealing ring and the circulating water pipe.
[0033] The magnetohydrodynamic sealing device 3 is connected to the beam pipe transition flange to achieve a rotary seal between the reaction target device and the front-end beam pipe transition flange. The transmission device 4 is connected to the magnetohydrodynamic sealing device 3, the internal slider of the water distributor 5, the internal pipe 6 of the reaction target, and the circulating water pipe 7. It is also connected to a motor via a synchronous belt to provide rotational power. The outer shell of the water distributor 5 is connected to the inlet and outlet water pipes, and the internal slider is connected to the circulating water pipe 7 to provide circulating water to the rotating pipe wall. The gray scissor indicates the direction of circulating water flow.
[0034] like Figure 5 As shown, the arrows indicate the beam direction for target application. In this embodiment, the water distributor 5 is equipped with an inlet 11, a rotary inlet 12, and an outlet 13. The magnetic fluid sealing device 3 has a magnetic fluid sealing shaft 15 in the middle, and a beam pipe adapter flange 16 is provided on the outside of the magnetic fluid sealing shaft 15. The transmission device 4 includes a reaction target transmission wheel 14, a motor 17, a synchronous belt 18, and a motor synchronous pulley 19. The reaction target 8 and the motor 17 are fixed on the same fixed bracket 20. The synchronous belt 18 is connected to the synchronous pulley 19 of the motor, and then connected to the reaction target drive wheel 14 to provide rotational power. The reaction target drive wheel 14 then drives the magnetic fluid sealing shaft 15, the internal slider of the water distributor, the internal pipe 6 of the reaction target, the circulating water pipe 7, and the reaction target 8 connected thereto to rotate at high speed. The outer shell of the water distributor is fixed on the bracket and remains stationary. The circulating water flows into the rotary water inlet 12 from the water inlet 11, flows through the circulating water pipe over the back of the reaction target 8, and then flows back through the other end of the circulating water pipe and the rotary water inlet 12. Finally, it flows out from the water outlet 13. The beam pipe adapter flange 16 is connected to the front end pipe of the accelerator. The deviation between the center of the reaction target 8 and the beam neutron is completely achieved by the adapter flange.
[0035] like Figure 6As shown, a beam pipe adapter flange 16 is provided on the outer side of the magnetohydrodynamic sealing shaft 15. The center position of the inner wall 21 of the beam pipe adapter flange is the beam target position, and the center of the inner wall 22 of the pipe inside the reaction target is the center of the reaction target. In this embodiment, the current beam target position is 7.5 mm away from the center of the reaction target 8. If it is necessary to adjust the eccentricity of the reaction target 8, it can be achieved by modifying the fixing bolt hole position of the beam pipe adapter flange 16. The eccentricity of the reaction target 8 is the distance between the beam target position and the center of the reaction target 8.
[0036] like Figure 7 As shown, the water distributor 5 has a ring-shaped structure. An inlet port 11 and an outlet port 13 are respectively provided on the upper and lower sides of the distributor housing 24. An internal slider 23 is provided inside the distributor 5. Circulating water loops connecting the inlet port 11 and the outlet port 13 are located on the upper and lower sides of the slider 23. Several rotating sealing rings 25 are provided on the side wall of the distributor 5. The rotating sealing rings 25 are used to seal the circulating water and separate the inlet and outlet water. The dimensions of the rotating sealing rings 25 can be adjusted according to actual conditions and needs. In this embodiment, three sets of rotating sealing rings 25 are provided; in fact, the number of rotating sealing rings 25 is not limited.
[0037] The prototype of the small eccentric rotating reaction target device disclosed in this invention was tested under normal operating conditions. The designed rotation speed was 1000 rpm, and the actual test results showed a stable speed of 1333 rpm and a stable vacuum level of 4.7E-4 Pa. Therefore, this prototype is fully capable of being applied to high-current experiments. Strict control should be exercised over the machining accuracy of each component during prototype fabrication. The resistance to rotation of the magnetohydrodynamic sealing device 3 and the water separator 5 under high-speed rotation should not be too high. For prolonged use, the rotating sealing components inside the water separator 5 need to be replaced to ensure safe operation of the device.
[0038] As can be seen from the above embodiments, the present invention discloses a small eccentric rotating reaction target device, which includes a magnetic fluid sealing device, a transmission device, a water distributor, an internal pipeline of the reaction target, a circulating water pipeline, and a reaction target. The front surface of the reaction target is vacuum-sealed with the internal pipeline of the reaction target through a sealing ring. One side of the circulating water pipe wall is connected to the internal slider of the water distributor, and the other side is sealed by a rear cover. The water passage of the water distributor, the water passage of the pipe wall, and the cavity between the back of the reaction target and the rear cover are connected to form a circulating water passage. The magnetic fluid sealing device is connected to the beam pipeline adapter flange to achieve a rotational seal between the device and the beam pipeline adapter flange. The transmission device is connected to the magnetic fluid sealing device, the internal slider of the water distributor, the internal pipeline of the reaction target, and the circulating water pipeline. The transmission device is connected to a motor through a synchronous belt to provide rotational power to the reaction target. The outer shell of the water distributor is connected to inlet and outlet water pipes, and the internal water passage of the water distributor is connected to the circulating water pipeline to provide circulating water to the rotating circulating water pipeline. The small eccentric rotating reaction target device disclosed in this invention can effectively reduce the maximum heat flux density borne by the reaction target, while increasing the effective usable area of the reaction target and extending the service life of the reaction target.
[0039] The device described in this invention is not limited to the embodiments described in the specific implementation. Other implementation methods derived by those skilled in the art based on the technical solution of this invention also fall within the scope of technical innovation of this invention.
Claims
1. A small-scale eccentric rotating reaction target device, characterized in that: The device includes a magnetohydrodynamic (MHD) sealing device, a transmission device, a water distributor, an internal pipeline of the reaction target, a circulating water pipeline, and the reaction target. The front surface of the reaction target is vacuum-sealed with the internal pipeline of the reaction target through a sealing ring. A MHD sealing shaft is installed in the MHD sealing device, and a beam pipeline adapter flange is installed on the outside of the MHD sealing shaft. The outside of the beam pipeline adapter flange is connected to the front end pipeline of the accelerator. The length of the reaction target cannot exceed the focusing length of the accelerator at the end of the pipeline. The outer diameter of the portion of the reaction target device entering the detector must not exceed the inner diameter of the detector, and the outer diameter of this portion of the reaction target device entering the detector must not exceed 8 cm. The center position of the beam pipeline adapter flange is the beam target position, and the center of the inner wall of the beam pipeline adapter flange is the center of the reaction target. There is an eccentricity between the beam target position and the center of the reaction target. The eccentricity of the reaction target is adjusted by modifying the fixing bolt hole positions of the beam pipeline adapter flange without changing the beam... The relative position of the spot and the detector is defined. One side of the circulating water pipe wall is connected to the internal slider of the water distributor, and the other side is sealed by the rear cover. The water passage of the water distributor, the water passage of the circulating water pipe, and the cavity between the back of the reaction target and the rear cover are connected to form a circulating water passage. The magnetic fluid sealing device is connected to the beam pipe adapter flange to achieve a rotary seal between the device and the beam pipe adapter flange. The transmission device is connected to the magnetic fluid sealing device, the internal slider of the water distributor, the internal pipe of the reaction target, and the circulating water pipe. The transmission device is connected to a motor through a synchronous belt to provide rotational power to the reaction target. Water inlet and water outlet are respectively provided on the upper and lower sides of the water distributor shell. Circulating water loops connecting the water inlet and water outlet are respectively provided on the upper and lower sides of the water distributor slider. The water distributor shell is connected to the water inlet and outlet pipes. The water passage inside the water distributor is connected to the circulating water pipe to provide circulating water for the rotating circulating water pipe.
2. The small eccentric rotating reaction target device as described in claim 1, characterized in that: A certain cavity is maintained between the rear cover and the reaction target to ensure the flow of circulating water.
3. The small eccentric rotating reaction target device as described in claim 1, characterized in that: The water distributor has a ring structure, and an internal slider is installed inside the water distributor.
4. The small eccentric rotating reaction target device as described in claim 3, characterized in that: Three rotating sealing rings are installed inside the water distributor.
5. A small eccentric rotating reaction target device as described in claim 3, characterized in that: The beam target position corresponds to the center of the reaction target.
6. The small eccentric rotating reaction target device as described in claim 5, characterized in that: The eccentricity of the reaction target is the distance between the beam firing position and the center of the reaction target.
7. A small eccentric rotating reaction target device as described in claim 6, characterized in that: The transmission device includes a reaction target drive wheel, a motor, a synchronous belt, and a motor synchronous pulley. The reaction target and the motor are fixed on the same fixed bracket. The synchronous belt is connected to the motor synchronous pulley and the synchronous belt is connected to the reaction target drive wheel to provide rotational power. The reaction target drive wheel drives the magnetohydrodynamic sealing shaft, the internal slider of the water distributor, the internal pipe of the reaction target, the circulating water pipe, and the reaction target to rotate at high speed.
8. A small eccentric rotating reaction target device as described in claim 7, characterized in that: The water distributor housing is fixed on the fixed bracket and remains stationary. Circulating water flows into the rotary water inlet from the water inlet, flows through the back of the reaction target, flows back from the other end of the rotary water inlet, and flows out from the water outlet.