A rotating target usable for monitoring with the particle-in-cell method

Abstract

The present application belongs to the technical field of neutron generator, and particularly relates to a rotating target which can be used for monitoring by accompanying particle method. The rotating target comprises a target chamber with a cylindrical structure, a target chamber sealing cover arranged at the bottom of the target chamber, an accompanying particle target tube, a beam pipeline and a target point monitoring pipeline which are respectively arranged on the side wall of the target chamber and are in communication with the target chamber, a lower part of a target system is arranged in the target chamber, an upper part of the target system penetrates through a magnetic fluid sealing device and is connected with a rotating system, an end part is fixed with a rotating joint, the rotating joint is connected with a cooling machine through a water pipe, the target system is sealed with the top of the target chamber through the magnetic fluid sealing device, and the target chamber forms an overall vacuum sealing. The rotating target is provided with an accompanying measurement system, the neutron yield is monitored in real time by the accompanying particle method, the target sheet temperature is imaged in real time through a thermal imager, the focusing state of the beam spot under different focusing conditions can be observed, and a basis is provided for beam adjustment, and a coaxial cooling structure design is adopted to reduce the driving structure as much as possible and achieve the compactness of the target body.

Description

Technical Field

[0001] This invention belongs to the field of neutron generator technology, specifically relating to a rotating target that can be used for monitoring using the adjoint particle method. Background Technology

[0002] The rotating target is a crucial component of the neutron generator, and temperature has a significant impact on it. For neutron intensities of 10... 11 High-current deuterium-tritium neutron generators with currents on the order of n / s and above can carry beam power of several kilowatts or even hundreds of kilowatts on their tritium targets during operation. If cooling measures are not taken to dissipate the heat from the target in a timely manner, a large amount of tritium will be released from the tritium-titanium film when the target temperature exceeds 200°C, potentially even burning out the target. Therefore, the design of the tritium target system for high-current deuterium-tritium neutron generators must first ensure that the target has good heat transfer performance. Simultaneously, while ensuring effective target cooling, the design must also consider the moderating effect of structural components of the tritium target system, such as the cooling medium and vacuum chamber, on the emitted neutrons. From a structural design perspective, the degree of interaction between structural components and neutrons should be minimized to ensure the monochromaticity of the neutron energy produced by the neutron generator and the accuracy of related experimental measurement data. Currently, the common methods for dealing with temperature factors are cooling water and high-speed rotating large-area target plates. The principle of rotating the target plate is to greatly increase the effective usable area of ​​the target plate by rotating it, thereby reducing the target plate temperature rise and increasing the target plate life. Summary of the Invention

[0003] To address the problems existing in the prior art, the purpose of this invention is to provide a rotating target that can be used for monitoring by the adjoint particle method. This solution can realize real-time monitoring of the neutron source yield in the DT reaction of a high-speed rotating target, as well as real-time monitoring of the source spot size and position during the use of the DT source.

[0004] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows:

[0005] A rotating target for accompanying particle monitoring includes a cylindrical target chamber, a target chamber sealing cover at the bottom of the target chamber, and accompanying particle target tubes, a beam pipe, and a target monitoring pipe respectively disposed on the side wall of the target chamber and communicating with the target chamber. The lower part of the target system is disposed in the target chamber, and the upper part is connected to the rotating system through a magnetohydrodynamic sealing device. The end is fixed to a rotary joint, and the rotary joint is connected to a cooler through a water pipe. The target system is sealed to the top of the target chamber through the magnetohydrodynamic sealing device, and the target chamber forms an overall vacuum seal.

[0006] Furthermore, the target system includes a target plate, a water cover, a double-layer cooling water pipe, and a connecting rod. The target plate and the water cover are connected parallel to each other and form a cavity between them. One end of the double-layer cooling water pipe is connected to the central opening of the target plate through the connecting rod.

[0007] Furthermore, the substrate material of the target plate is oxygen-free copper, and the surface is coated with a layer of tritium-titanium film. The water cover, double-layer cooling water pipes and connecting rods are all made of stainless steel, and the connection between the target plate and the water cover is made of silver brazing.

[0008] Furthermore, in the target system, cooling water enters the cavity between the target plate and the water cover through the inner layer of the double-layer cooling water pipe, and flows out through the outer layer of the double-layer cooling water pipe.

[0009] Furthermore, the tail end of the double-layer cooling water pipe is fixed and sealed to the rotary joint by a fixing nut with a rubber pad.

[0010] Furthermore, the rotation system is a hollow stepper motor, which is fixed to the side of the rotating target support. A double-layer cooling water pipe runs through the hollow stepper motor, and the entire target system is rotated by fixing the double-layer cooling water pipe with set screws.

[0011] Furthermore, an Au-Si surface barrier detector is installed at the end of the accompanying particle target tube to monitor neutron yield in real time using the accompanying particle method.

[0012] Furthermore, a thermal imager is installed at the end of the target monitoring pipeline to perform real-time imaging of the target temperature.

[0013] Furthermore, a particle accelerator is connected to the end of the beam pipe, and the accelerated particles enter the target chamber through the beam pipe to bombard the target sheet.

[0014] The beneficial effects of this invention are as follows:

[0015] 1. Equipped with an adjoint measurement system, it monitors neutron yield in real time using the adjoint particle method;

[0016] 2. By using a thermal imager to image the temperature of the target in real time, the focusing state of the beam spot under different focusing conditions can be observed, providing a basis for beam current adjustment;

[0017] 3. The coaxial cooling structure design minimizes the driving structure, resulting in a compact target. The structural materials at the target end are optimized to be as simple as possible, which can significantly reduce neutron scattering and is beneficial for tests with significant neutron scattering effects, such as labeled neutron imaging experiments.

[0018] 4. The compact structure of the magnetofluid can reduce the alternating magnetic field of the magnetofluid, thus minimizing the impact of the magnetic field on the measurement system;

[0019] 5. The rotating target drive pipe, the accompanying particle target pipe, the beam pipe, and the target monitoring pipe are all on the same side, minimizing the experimental structure components in the neutron emission direction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a rotating target that can be used for monitoring by the accompanying particle method according to the present invention.

[0021] Figure 2 This is a schematic diagram of the target system.

[0022] In the above figures, 1. Accompanying particle target tube; 2. Target chamber; 3. Target plate; 4. Target chamber sealing cover; 5. Double-layer cooling water pipe; 6. Beam pipe; 7. Magnetohydrodynamic sealing device; 8. Thermal imager; 9. Target monitoring pipe; 10. Fixing nut; 11. Rotary joint; 12. Rotating target support; 13. Hollow stepper motor; 14. Au-Si surface barrier detector; 15. Water cover; 16. Connecting rod. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] The rotating target of the present invention, such as Figure 1 As shown, under the conditions of use, it includes a target chamber 2, an accompanying particle target tube 1, a beam pipe 6, a target monitoring pipe 9, a target chamber sealing cover 4, a magnetohydrodynamic sealing device 7, a target system, a rotating system, and a rotary joint 11.

[0025] like Figure 2 As shown, the target system is welded together from a target plate 3, a water cover 15, a double-layer cooling water pipe 5, and a connecting rod 16. The target plate 3 and the water cover 15 are connected parallel to each other, forming a cavity between them. One end of the double-layer cooling water pipe 5 is connected to the center opening of the target plate 3 via the connecting rod 16. The connecting rod 16 is detachably connected to the target plate 3 and the outer layer of the double-layer cooling water pipe 5 for easy installation and replacement. The base material of the target plate 3 is oxygen-free copper, with a tritium-titanium film plated on the surface. The water cover 15, the double-layer cooling water pipe 5, and the connecting rod 16 are all made of stainless steel. The connection between the target plate 3 and the water cover 15 is achieved by silver brazing.

[0026] The rotation system is a hollow stepper motor 13, which is fixed to the side of the rotating target bracket 12. A double-layer cooling water pipe 5 passes through the hollow stepper motor, and the double-layer cooling water pipe 5 is fixed by a set screw to rotate the entire target system.

[0027] The target chamber 2 is a cylindrical structure. A target chamber sealing cover 4 is located at the bottom of the target chamber 2. An accompanying particle target tube 1, a beam channel 6, and a target monitoring channel 9, all communicating with the target chamber 2, are respectively installed on the side walls of the target chamber 2. The beam channel 6 is tubular, with its end furthest from the target chamber 2 connected to a particle accelerator. Accelerated particles (e.g., deuterium ions) enter the target chamber 2 through the beam channel 6 to bombard the target sheet 3. The accompanying particle target tube 1 is tubular, and an Au-Si surface barrier detector 14 is located at the end of the accompanying particle target tube 1 furthest from the target chamber 2, monitoring neutron yield in real time using the accompanying particle method. The target monitoring channel 9 is tubular, and a thermal imager 8 is located at the end of the target monitoring channel 9 furthest from the target chamber 2, monitoring through an observation window.

[0028] The target plate 3 is set on the inner bottom surface of the target chamber 2. The double-layer cooling water pipe 5 passes through the magnetohydrodynamic sealing device 7 and is sealed to the top of the target chamber 2 through the magnetohydrodynamic sealing device 7, forming an integrally sealed vacuum target chamber. The tail end of the double-layer cooling water pipe 5 is fixed and sealed to the rotary joint 11 by a fixing nut 10 with a rubber gasket. The rotary joint 11 is connected to the cooler through a water pipe. One side of the rotary joint 11 is connected to the inlet water pipe, and the other side is connected to the outlet water pipe. The cooler presses cooling water into the inner layer of the double-layer cooling water pipe 5 through the inlet water pipe of the rotary joint 11. Under the guidance of the inner layer of the cooling water pipe 5, the cooling water enters the cavity between the target plate 3 and the water cover 15 from the center of the target plate 3. Due to the high-speed rotation of the target plate 3, the cooling water moves from the center of the cavity to the periphery of the cavity under centrifugal force, cooling the target plate 3 in the cavity. Then, the cooling water enters the outer layer of the cooling water pipe 5 and flows back to the cooler through the outlet water pipe of the rotary joint 11 under the guidance of the outer layer of the cooling water pipe 5. The design employs a coaxial cooling structure, minimizing the drive structure and resulting in a compact target chamber. The target tip utilizes simple and optimized materials to reduce slowing effects on emitted neutrons. The target is connected to a support frame via a cooling transmission rod, facilitating installation and replacement.

[0029] The substrate material of target plate 3 is oxygen-free copper, with a tritium-titanium film coated on its surface. When deuterium ions enter target chamber 2 through beam channel 6 and bombard target plate 3, the tritium in the titanium film interacts with the deuterium ions to produce neutrons and alpha particles. This is the working principle of the rotating target. Au-Si surface barrier detector 14 detects alpha particles, enabling real-time monitoring of neutron yield through the adjoint particle method. When a high-intensity deuterium ion beam bombards target plate 3, a large amount of thermal deposition occurs on the surface of target plate 3. The temperature of target plate 3 is imaged in real time by thermal imager 8, allowing observation of the beam spot focusing state under different focusing conditions and providing a basis for beam adjustment.

[0030] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention is also intended to include these modifications and variations.

Claims

1. A rotating target for accompanying particle monitoring, comprising a cylindrical target chamber (2), a target chamber sealing cover (4) disposed at the bottom of the target chamber (2), an accompanying particle target tube (1), a beam pipe (6), and a target monitoring pipe (9) disposed on the side wall of the target chamber (2) and communicating with the target chamber (2), characterized in that: The lower part of the target system is set inside the target chamber (2), and the upper part is connected to the rotating system through the magnetic fluid sealing device (7). The end is fixed to the rotary joint (11). The rotary joint (11) is connected to the cooler through a water pipe. The target system is sealed to the top of the target chamber (2) through the magnetic fluid sealing device (7), and the target chamber (2) forms an overall vacuum seal. The target system includes a target plate (3), a water cover (15), a double-layer cooling water pipe (5), and a connecting rod (16). The target plate (3) and the water cover (15) are connected to each other in parallel and face each other, forming a cavity between the target plate (3) and the water cover (15). One end of the double-layer cooling water pipe (5) is connected to the center opening of the target plate (3) through the connecting rod (16).

2. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: The substrate material of the target plate (3) is oxygen-free copper, and the surface is coated with a layer of tritium titanium film. The water cover (15), the double-layer cooling water pipe (5) and the connecting rod (16) are all made of stainless steel. The connection between the target plate (3) and the water cover (15) is made of silver brazing.

3. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: In the target system, cooling water enters the cavity between the target plate (3) and the water cover (15) through the inner tube of the double-layer cooling water pipe (5) and flows out through the outer tube of the double-layer cooling water pipe (5).

4. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: The tail end of the double-layer cooling water pipe (5) is fixed and sealed to the rotary joint (11) by a fixing nut (10) with a rubber pad.

5. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: The rotation system is a hollow stepper motor (13), which is fixed to the side of the rotating target bracket (12). A double-layer cooling water pipe (5) passes through the hollow stepper motor (13), and the double-layer cooling water pipe (5) is fixed by a set screw to rotate the entire target system.

6. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: An Au-Si surface barrier detector (14) is installed at the end of the accompanying particle target tube (1) to monitor the neutron yield in real time using the accompanying particle method.

7. The rotating target for monitoring using the accompanying particle method as described in claim 1, characterized in that: A thermal imager (8) is installed at the end of the target monitoring pipe (9) to perform real-time imaging of the temperature of the target piece (3).

8. The rotating target for accompanying particle monitoring as described in claim 1, characterized in that: The beam pipe (6) is connected to a particle accelerator at the end. Accelerated particles enter the target chamber (2) through the beam pipe (6) and bombard the target sheet (3).

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