A high voltage conditioning device for a neutron tube

Abstract

The application relates to the technical field of nuclear physics, in particular to a high-voltage aging device for a neutron tube, which comprises a high-voltage direct-current power supply, an oil drum, a neutron tube, a neutron tube connecting assembly, fixing bolts and a sinking plate; the high-voltage direct-current power supply is connected with the neutron tube in series through the neutron tube connecting assembly and the fixing bolts and is grounded, and the neutron tube is completely immersed in insulating oil. The method is mainly suitable for subsequent treatment of improving the quality and high-pressure resistance of the neutron tube after exhausting and sealing. The method eliminates free conductive particles in the neutron tube and accelerates the surface burrs of the accelerating electrode by applying high-voltage to the neutron tube through the high-voltage direct-current power supply to make the neutron tube internally generate sharp-point discharge, improves the voltage resistance of the neutron tube, prolongs the service life of the neutron tube and makes the neutron tube reach the best performance.

Description

Technical Field

[0001] This invention relates to the field of nuclear physics, and more particularly to a high-voltage aging device for neutron tubes. Background Technology

[0002] A neutron tube is a small, sealed accelerator capable of producing neutrons, widely used in nuclear physics research, materials analysis, and medical diagnostics. In existing technologies, residual metal particles and micro-protrusions on the accelerating electrode surface remain during the neutron tube manufacturing process, leading to a decrease in its withstand voltage performance. Therefore, after degassing and sealing, neutron tubes require aging treatment to improve their high-voltage withstand performance and overall quality. Unlike traditional aging methods, the equipment and processes used by Milun of the Institute of Electronic Engineering, China Academy of Engineering Physics (Development of a Programmable Neutron Tube Aging Platform, Nuclear Electronics & Detection Technology, 2006, (05): 619-622.) are complex. They use pulsed voltage for aging and employ air as the dielectric for partial discharge treatment, which cannot effectively eliminate deep-seated conductive particles, posing a risk of breakdown and insufficient treatment depth. After conventional treatment, the withstand voltage of the neutron tube can only reach 80kV, with a pass rate of less than 65%.

[0003] Whether it is conventional aging or aging using pulse voltage, there are problems such as incomplete aging and poor withstand voltage performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-voltage aging device for neutron tubes, which, when used with appropriate methods, can solve problems such as complex equipment processes, incomplete cleaning of the neutron tube interior, and insufficient pressure resistance in existing technologies through simple operation.

[0005] In view of the aforementioned background issues, this invention proposes a novel neutron tube aging method based on a high-voltage DC power supply and aging in insulating oil. This method uses a simple experimental setup, adjusting the voltage of the high-voltage DC power supply and utilizing the principle of tip discharge to control the aging of the neutron tube, significantly improving its withstand voltage performance and thus extending its service life. Given the rapid development and application of neutron tube technology, this aging method has significant application value.

[0006] This method is mainly applicable to the subsequent processing to improve the quality and high pressure resistance of neutron tubes after exhaust sealing.

[0007] The objective of this invention is achieved through the following technical solution: The high-voltage aging device for this type of neutron tube includes a high-voltage DC power supply, an oil tank, a neutron tube, a neutron tube connecting assembly, fixing bolts, and a recessed plate. The high-voltage DC power supply is connected to the top of the fixing bolts via a high-voltage cable, and the bottom of the fixing bolts is connected to the neutron tube connecting assembly via a wire. The bottom of the neutron tube is fixed to the recessed plate via the neutron tube connecting assembly, while the top of the neutron tube is grounded to the high-voltage DC power supply, forming a closed loop circuit. High voltage is applied to the neutron tube by adjusting the high-voltage DC power supply.

[0008] The high-voltage DC power supply output is continuously adjustable from 0-120kV and can be controlled remotely or locally; the oil tank is made of 316L stainless steel and contains insulating oil with a dielectric strength ≥80kV / 2.5mm; the neutron tube connection assembly and fixing bolts are made of oxygen-free copper; the sink plate is made of polytetrafluoroethylene and has drainage holes on its surface.

[0009] Based on the device described above, the present invention also proposes a aging method in conjunction with the device, specifically including the following steps: 1) First, ensure that all parts of the device are correctly wired, that the neutron tube and the high-voltage DC power supply are grounded, and that the oil drum is filled with insulating oil; 2) Adjust the voltage of the high-voltage DC power supply. Initially, increase it at a rate of 1kV per second until the neutron tube discharges. Maintain the current voltage for aging until the neutron tube stops discharging, then continue to increase the voltage. 3) The aging voltage is increased by 10kV at a rate of 1kV per second. After aging until the neutron tube stops discharging, the voltage is increased further, up to a maximum of 120kV. 4) Repeat the process of increasing the voltage from 0kV to 120kV at a rate of 1kV per second, 2 to 3 times. If the neutron tube discharges, repeat steps 2) and 3). If no discharge occurs, the aging process is complete.

[0010] In step 1) above, the level of insulating oil needs to be ≥50mm above the top of the neutron tube.

[0011] Beneficial effects: Compared with existing mature technologies, the present invention has the following advantages: The aging process is highly effective, deeply cleaning free conductive particles and burrs on the accelerating electrode surface of the neutron tube, thus improving its insulation withstand voltage and lifespan. This is because the aging process is controllable; by gradually increasing the aging voltage, the withstand voltage performance of the neutron tube under various voltage conditions is fully guaranteed. The device and its principle are simple. Compared with existing aging devices, this device only requires a high-voltage DC power supply, an oil tank and related connectors. The entire aging process can be completed by using the principle of tip discharge, which reduces the experimental cost. The system is well-established, with convenient parameter control and adjustment, making it easy for personnel to operate. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a high-voltage aging device for neutron tubes. Among them: 1: High voltage DC power supply; 2: Oil drum; 3: Neutron tube; 4: Neutron tube connecting assembly; 5: Fixing bolt; 6: Recessed plate. Detailed Implementation

[0013] The present invention will now be described in further detail with reference to the accompanying drawings: The high-voltage aging device for the neutron tube in this invention is configured as follows: Figure 1 As shown. It includes a high-voltage DC power supply 1, an oil drum 2, a neutron tube 3, a neutron tube connecting assembly 4, fixing bolts 5, and a recessed plate 6. The high-voltage DC power supply 1 and fixing bolts 5 are connected via a high-voltage cable, and then the fixing bolts 5 are connected to the neutron tube connecting assembly 4 with a wire. The bottom of the neutron tube 3 is fixed to the recessed plate 6 via the neutron tube connecting assembly 4, while the top of the neutron tube 3 is grounded to the high-voltage DC power supply 1, forming a closed-loop circuit. High voltage is applied to the neutron tube 3 by adjusting the high-voltage DC power supply 1.

[0014] The high-voltage DC power supply 1 has a continuously adjustable output of 0-120kV and can be controlled remotely or locally; the oil tank 2 is made of 316L stainless steel and is filled with insulating oil with a dielectric strength ≥80kV / 2.5mm; the neutron tube connection assembly 4 and fixing bolts 5 are made of oxygen-free copper; the sink plate 6 is made of polytetrafluoroethylene and has drainage holes on its surface.

[0015] The aging method involved in this invention is described as follows: 1) First, ensure that all parts of the device are correctly wired, and that neutron tube 3 and high-voltage DC power supply 1 are grounded, and that the oil drum is filled with insulating oil; 2) Adjust the voltage of the high voltage DC power supply 1. Initially, increase it at a rate of 1kV per second until the neutron tube 3 discharges. Maintain the current voltage for aging until the neutron tube stops discharging, then continue to increase the voltage. 3) The aging voltage is increased by 10kV at a rate of 1kV per second. After aging until the neutron tube stops discharging, the voltage is increased further, up to a maximum of 120kV. 4) Repeat the process of increasing the voltage from 0kV to 120kV at a rate of 1kV per second, 2 to 3 times. If the neutron tube discharges, repeat steps 2) and 3). If no discharge occurs, the aging process is complete.

[0016] In summary, the neutron tube aging apparatus of this invention utilizes a high-voltage DC power supply to perform aging experiments on a neutron tube. The aging method based on this apparatus involves controlling and adjusting the high voltage applied to the neutron tube by the high-voltage DC power supply, causing a point discharge inside. This method can simply and efficiently eliminate free conductive particles inside the neutron tube and burrs on the accelerating electrode surface, improving the neutron tube's withstand voltage performance, thereby extending its service life and enabling the neutron tube to achieve optimal performance.

Claims

1. A high-voltage aging device for a neutron tube, characterized in that: The system includes a high-voltage DC power supply (1), an oil drum (2), a neutron tube (3), a neutron tube connection assembly (4), a fixing bolt (5), and a recessed plate (6). The high-voltage DC power supply (1) and the fixing bolt (5) are connected by a high-voltage cable, and the fixing bolt (5) is connected to the neutron tube connection assembly (4) by a wire. The bottom of the neutron tube (3) is fixed to the recessed plate (6) through the neutron tube connection assembly (4), while the top of the neutron tube (3) is grounded to the high-voltage DC power supply (1), forming a closed loop. High voltage is applied to the neutron tube (3) by adjusting the high-voltage DC power supply (1).

2. The high-voltage aging device for a neutron tube according to claim 1, characterized in that: The high-voltage DC power supply (1) outputs 0-120kV continuously adjustable and can be controlled remotely or locally.

3. The high-voltage aging device for a neutron tube according to claim 1, characterized in that: The oil drum (2) is made of 316L stainless steel and is filled with insulating oil with a dielectric strength ≥80kV / 2.5mm.

4. The high-voltage aging device for a neutron tube according to claim 1, characterized in that: The neutron tube connecting assembly (4) and fixing bolt (5) are made of oxygen-free copper.

5. The high-voltage aging device for a neutron tube according to claim 1, characterized in that: The sink plate (6) is made of polytetrafluoroethylene and has drainage holes on its surface.

6. The high-voltage aging device for a neutron tube according to claim 3, characterized in that: The insulating oil level needs to be ≥50mm higher than the top of the neutron tube (3).

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