Single-direction buffer chemical corrosion system and method for semi-closed radio frequency superconducting cavity

Abstract

The invention relates to the technical field of surface treatment of radio frequency superconducting cavities, in particular to a unidirectional buffer chemical corrosion system and method for a semi-closed radio frequency superconducting cavity. A unidirectional buffer chemical corrosion system for a semi-closed radio frequency superconducting cavity comprises an acid mixing unit, a magnetic pump for mixing acid, a superconducting cavity internal acid inlet pipeline and a superconducting cavity internal acid outlet pipeline, the acid mixing unit is used for mixing the buffer chemical corrosion liquid in a preset proportion to obtain mixed acid; the magnetic pump for the mixed acid is used for conveying the mixed acid from the acid mixing unit to the acid inlet pipeline in the superconducting cavity; the superconducting cavity internal acid inlet pipeline is used for covering the mixed acid on the inner surface of the superconducting cavity to buffer chemical corrosion; and the acid outlet pipeline in the superconducting cavity is used for discharging the mixed acid after the buffer chemical corrosion reaction out of the superconducting cavity through a magnetic pump for the mixed acid. According to the method, the acid liquor inlet and outlet path is designed at the unique tuning port of the semi-closed radio frequency superconducting cavity, so that the limitation that only the radio frequency superconducting cavity with two open ends can be processed in the traditional method is overcome.

Description

Technical Field

[0001] The present application relates to the technical field of surface treatment of radio frequency superconducting cavities, and in particular to a single-direction buffered chemical etching system and method for a semi-enclosed radio frequency superconducting cavity. Background Art

[0002] The whole-cavity buffered chemical corrosion process of the RF superconducting cavity is to make the RF surface of the niobium RF superconducting cavity react with nitric acid and hydrofluoric acid. The reacted niobium will be corroded and peeled off to remove the processing contamination layer.

[0003] The traditional buffered chemical etching of RF superconducting cavities uses a vertically fixed RF superconducting cavity, and the mixed acid is transported to a high-level acid tank by a magnetic pump, and then the mixed acid is transported to a pipe connected to the RF superconducting cavity by a magnetic pump through a pipe. The mixed acid is discharged from the bottom to the top, and the exhaust gas is discharged from the acid outlet at the highest position to remove the RF surface contamination layer and defects. The traditional buffered chemical polishing method of RF superconducting cavities is usually designed for a standard structure with two open ends, so that the acid can be introduced from one end and discharged from the other end to corrode the RF surface of the RF superconducting cavity, thereby completing the treatment of the entire cavity.

[0004] However, for a semi-enclosed RF superconducting cavity with only a single tuning port, there are not enough inlets and outlets to guide the inflow and outflow of acid. The traditional treatment method cannot achieve effective pickling of the entire cavity. Therefore, the existing buffered chemical polishing technology has limitations when facing semi-enclosed structures and cannot meet the surface treatment requirements of this type of special structure RF superconducting cavity. Summary of the invention

[0005] In view of this, it is necessary to provide a unidirectional buffered chemical etching system and method for a semi-enclosed RF superconducting cavity to make up for the defect that the prior art cannot perform effective buffered chemical polishing for semi-enclosed RF superconducting cavities.

[0006] A semi-enclosed radio frequency superconducting cavity unidirectional buffer chemical corrosion system, comprising: a mixed acid unit, a magnetic pump for mixed acid, an acid inlet pipe inside the superconducting cavity, and an acid outlet pipe inside the superconducting cavity; The mixed acid unit is used to mix buffered chemical etching solutions of a preset ratio to obtain a mixed acid; The mixed acid magnetic pump is used to transport the mixed acid from the mixed acid unit to the acid inlet pipeline inside the superconducting cavity; The acid inlet pipe in the superconducting cavity is used to cover the mixed acid on the inner surface of the superconducting cavity for buffering chemical corrosion; The acid outlet pipe inside the superconducting cavity is used to discharge the mixed acid after buffering the chemical corrosion reaction out of the superconducting cavity through the mixed acid magnetic pump.

[0007] Preferably, the acid outlet pipe inside the superconducting cavity is provided with a small hole.

[0008] Preferably, the open port of the superconducting cavity is provided with a sealing plate for sealing, and the sealing plate is provided with an inlet and an outlet respectively connected with an acid inlet pipe and an acid outlet pipe inside the superconducting cavity.

[0009] Preferably, it further comprises a high-pressure nitrogen source, which is used to introduce high-pressure nitrogen into the superconducting cavity through the inlet and press the mixed acid out of the superconducting cavity through the outlet.

[0010] Preferably, the acid outlet pipe inside the superconducting cavity is connected to the mixed acid unit through the outlet, and the mixed acid discharged from the superconducting cavity enters the mixed acid unit.

[0011] Preferably, it further comprises an exhaust gas treatment unit; the mixed acid unit is provided with an exhaust outlet, and the exhaust gas treatment unit is connected to the exhaust outlet of the mixed acid unit to absorb the exhaust gas in the mixed acid unit.

[0012] Preferably, valves are provided between the acid inlet pipe inside the superconducting cavity and the acid outlet pipe inside the superconducting cavity and the magnetic pump for mixed acid, respectively.

[0013] Compared with the prior art, the beneficial effect of the present application is that: by designing the acid inlet and outlet path at the only tuning port of the semi-enclosed RF superconducting cavity, the limitation that the traditional method can only process the RF superconducting cavity with openings at both ends is overcome. In addition, by setting small holes in the pipeline inside the superconducting cavity, the design of these small holes enables the acid to flow in a predetermined direction, thereby ensuring that every area of ​​the RF superconducting cavity can be processed, solving the problem that the semi-enclosed RF superconducting cavity cannot perform the entire cavity surface treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the buffer chemical corrosion structure of the existing radio frequency superconducting cavity.

[0015] Figure 2 It is a structural schematic diagram of a semi-closed superconducting cavity.

[0016] Figure 3 It is a structural schematic diagram of a unidirectional buffer chemical etching system of a semi-enclosed radio frequency superconducting cavity provided by the present application.

[0017] Figure 4 It is a schematic diagram of the structure of an internal tooling of a semi-enclosed radio frequency superconducting cavity provided in the present application.

[0018] Figure 5 It is a schematic flow chart of a single-direction buffered chemical etching method for a semi-enclosed radio frequency superconducting cavity provided in the present application. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the buffer chemical corrosion structure of the existing RF superconducting cavity. The buffer chemical corrosion of the existing RF superconducting cavity adopts the RF superconducting cavity to be placed vertically and fixed, and the mixed acid adopts the method of bottom-in and top-out. The exhaust gas is discharged from the acid outlet at the highest position. Due to the different designs of the RF superconducting cavity structure, different acid inlet and outlet interfaces are designed. The mixed acid corrodes the RF surface of the RF superconducting cavity to remove the RF surface contamination layer and defects. For the superconducting cavity with a semi-enclosed structure such as Figure 2 As shown, Figure 2 It is a structural diagram of a semi-closed superconducting cavity. Because this cavity type has only one tuning port, the traditional buffered chemical method cannot complete the pickling treatment of the entire cavity. It is necessary to reconsider a new pickling method to ensure buffered chemical polishing in a semi-closed state.

[0021] Therefore, the present application provides a unidirectional buffer chemical etching system for a semi-enclosed radio frequency superconducting cavity. Figure 3-Figure 4 , Figure 3 It is a structural schematic diagram of a unidirectional buffer chemical etching system of a semi-enclosed radio frequency superconducting cavity provided by the present application; Figure 4 The unidirectional buffer chemical corrosion system of the semi-enclosed radio frequency superconducting cavity comprises: a mixed acid unit, a magnetic pump for mixed acid, an acid inlet pipe inside the superconducting cavity, and an acid outlet pipe inside the superconducting cavity.

[0022] The mixed acid unit is used to mix the buffered chemical etching liquids of the preset ratio to obtain the mixed acid. The buffered chemical etching liquid of the preset ratio can be mixed into the mixed acid in the volume ratio of nitric acid (65%): hydrofluoric acid (40%): phosphoric acid (78%) = 1:1:2. In addition, an acid preparation unit can be provided to pour various buffered chemical etching liquids into the acid preparation unit, and then transport them to the mixed acid unit through a pipeline for mixing.

[0023] Furthermore, since heat may be generated when the buffered chemical etching liquid is mixed to obtain the mixed acid, a heat exchanger can also be set in the system to output the heat of the mixed acid to the coolant, so as to cool the acid liquid and control the temperature of the mixed acid within a suitable temperature range. Within a suitable temperature range, the chemical reaction rate of the mixed acid on the surface of the radio frequency superconducting cavity is moderate, which can effectively remove pollutants and defects on the surface without causing excessive corrosion or unnecessary damage too quickly. At the same time, it also helps to improve the safety and controllability of the operation, for example, 11-14 degrees Celsius.

[0024] The mixed acid magnetic pump is used to transport the mixed acid to the acid pipeline inside the superconducting cavity. The mixed acid magnetic pump can be a pneumatic diaphragm pump. In addition to being used to transport the mixed acid to the acid pipeline inside the superconducting cavity, the mixed acid magnetic pump can also be used to pump the mixed acid out of the superconducting cavity after the buffered chemical corrosion reaction.

[0025] The acid inlet pipe inside the superconducting cavity is used to cover the mixed acid on the inner surface of the superconducting cavity for buffering chemical corrosion. Furthermore, the acid outlet pipe inside the superconducting cavity is provided with small holes to allow the mixed acid to flow along a predetermined path, ensuring that the acid can cover all areas that need to be treated, avoiding omissions or over-treatment. Then, the mixed acid after the buffering chemical corrosion reaction is discharged from the superconducting cavity through the acid outlet pipe inside the superconducting cavity by a mixed acid magnetic pump, and refluxed to the mixed acid unit for cooling again, so that the mixed acid forms a closed loop.

[0026] Furthermore, the system also includes a tail gas treatment unit, and the mixed acid unit is provided with an exhaust outlet. The tail gas treatment unit is connected to the exhaust outlet of the mixed acid unit, and is used to absorb the exhaust gas in the mixed acid unit, and then discharge it after the tail gas meets the standard. By absorbing the exhaust gas through the tail gas treatment unit, the emission of harmful gases can be significantly reduced and the environment can be protected. The tail gas treatment unit can be a spray absorption tower, which can capture and treat toxic and harmful components in the exhaust gas, reduce harm to operators and the surrounding environment, and improve operational safety. In addition, the introduction of the tail gas treatment unit improves the function of the overall system, making the chemical corrosion polishing process more complete. The solution of the present application not only focuses on the surface treatment of the cavity, but also pays attention to the exhaust gas treatment link.

[0027] Furthermore, a sealing plate can be provided at the open port of the semi-enclosed RF superconducting cavity for sealing, and the sealing plate is provided with an inlet and an outlet respectively connected to the acid inlet pipe inside the superconducting cavity and the acid outlet pipe inside the superconducting cavity. The use of a sealing plate can create a closed environment to prevent acid leakage and external impurities from entering the superconducting cavity. It can ensure that the acid enters and leaves the cavity only through the designed inlets and outlets during the buffered chemical etching polishing (BCP) treatment, thereby ensuring the controllability and safety of the pickling process. In some embodiments, the sealing plate can be made of a polytetrafluoroethylene plate. The polytetrafluoroethylene material is very suitable for this application scenario due to its excellent corrosion resistance and chemical stability.

[0028] Furthermore, the acid inlet and outlet designed on the PTFE plate can be matched with valves to control the flow rate and switch of the acid solution, making the entire treatment process more accurate and efficient.

[0029] Furthermore, based on the sealing plate, inlet and outlet provided at the open port of the semi-enclosed RF superconducting cavity, after the BCP (Buffer Chemical Polishing) is completed, the acid liquid remaining in the superconducting cavity can be pressed out of the superconducting cavity through a pre-designed outlet using high-pressure nitrogen.

[0030] Specifically, high-pressure nitrogen is introduced into the interior of the radio frequency superconducting cavity through an appropriate interface, which may be the above-mentioned inlet or an interface specially designed for high-pressure nitrogen.

[0031] Then, the pressure of high-pressure nitrogen is used to squeeze the residual acid liquid in the cavity so that it is discharged from the cavity through the above-mentioned outlet or other designed acid liquid outlets.

[0032] Furthermore, after the high-pressure nitrogen gas has pressed the acid out, pure water can be poured in again and circulated and flushed at a certain flow rate to ensure that the residual acid on the inner surface of the superconducting cavity is completely removed.

[0033] Based on the same inventive concept, the present application also provides a semi-enclosed RF superconducting cavity unidirectional buffered chemical etching method based on the above-mentioned semi-enclosed RF superconducting cavity unidirectional buffered chemical etching system, such as Figure 5 The schematic flow chart of the buffer chemical etching method for a semi-enclosed radio frequency superconducting cavity in one direction shown in the figure comprises the following steps: S201: transporting the mixed acid to an acid inlet pipe in the radio frequency superconducting cavity.

[0034] S202: Covering the inner surface of the radio frequency superconducting cavity with mixed acid through an acid inlet pipe for buffered chemical corrosion.

[0035] S203: Recover the mixed acid through the small holes provided in the acid outlet pipeline.

[0036] S204: Use high-pressure nitrogen to press the acid remaining in the superconducting cavity out of the superconducting cavity.

[0037] Furthermore, after the acid remaining in the superconducting cavity is pressed out of the superconducting cavity by high-pressure nitrogen, the superconducting cavity is cleaned by pure water.

[0038] Furthermore, the mixed acid is recovered through the acid outlet pipeline, and the waste gas in the recovery process is absorbed and treated until it meets the standards before exhaust gas discharge.

[0039] In summary, the present application is particularly aimed at a semi-enclosed radio frequency superconducting cavity, and the direction of the acid is controlled by designing a special tooling, and the pickling treatment of the entire cavity is completed through a single port. The buffered chemical etching solution mixed in a certain proportion also controls the temperature of the mixed acid to achieve a better decontamination effect, and then the mixed acid is transported to the inside of the superconducting cavity using a magnetic pump. In addition, a pipeline inside the superconducting cavity is designed, and a tooling with small holes is set on the pipeline to ensure the flow direction of the acid inside the cavity, so as to achieve a uniform treatment effect. Through a closed-loop circulation method, the acid can be recycled and cooled down for use again, thereby improving the utilization rate of the acid and reducing material costs. For the exhaust gas generated in the above process, the present application also absorbs the exhaust gas through a tail gas treatment unit to ensure that the exhaust gas meets the emission standards, which helps to reduce environmental pollution. After the buffered chemical corrosion, a high-pressure nitrogen cleaning step is also introduced, and the acid remaining in the superconducting cavity is squeezed out by high-pressure nitrogen, and the cavity surface is further purified by circulating pure water.

[0040] Through the above improvements, the surface treatment problem of semi-closed structure radio frequency superconducting cavity is effectively solved.

Claims

1. A unidirectional buffer chemical etching system for a semi-enclosed radio frequency superconducting cavity, characterized in that: It includes a mixed acid unit, a magnetic pump for mixed acid, an acid inlet pipe inside the superconducting cavity, and an acid outlet pipe inside the superconducting cavity; The mixed acid unit is used to mix buffered chemical etching solutions of a preset ratio to obtain a mixed acid; The mixed acid magnetic pump is used to transport the mixed acid from the mixed acid unit to the acid inlet pipeline inside the superconducting cavity; The acid inlet pipe in the superconducting cavity is used to cover the mixed acid on the inner surface of the superconducting cavity for buffering chemical corrosion; The acid outlet pipe inside the superconducting cavity is used to discharge the mixed acid after buffering the chemical corrosion reaction out of the superconducting cavity through the mixed acid magnetic pump.

2. The system according to claim 1, characterized in that The acid outlet pipe inside the superconducting cavity is provided with small holes.

3. The system according to claim 1, characterized in that The open port of the superconducting cavity is provided with a sealing plate for sealing, and the sealing plate is provided with an inlet and an outlet respectively connected with an acid inlet pipe and an acid outlet pipe inside the superconducting cavity.

4. The system according to claim 3, characterized in that It also includes a high-pressure nitrogen source, which is used to introduce high-pressure nitrogen into the superconducting cavity through the inlet and press the mixed acid out of the superconducting cavity through the outlet.

5. The system according to claim 3, characterized in that The acid outlet pipe inside the superconducting cavity is connected with the mixed acid unit through the outlet, and the mixed acid discharged from the superconducting cavity enters the mixed acid unit.

6. The system according to claim 5, characterized in that Also includes an exhaust gas treatment unit; The mixed acid unit is provided with an exhaust outlet, and the tail gas treatment unit is communicated with the exhaust outlet of the mixed acid unit for absorbing the exhaust gas in the mixed acid unit.

7. The system according to claim 1, characterized in that Valves are provided between the acid inlet pipe inside the superconducting cavity and the acid outlet pipe inside the superconducting cavity and the magnetic pump for mixed acid, respectively.

8. A method for unidirectional buffered chemical etching of a semi-enclosed radio frequency superconducting cavity, characterized in that: Based on the unidirectional buffered chemical etching system of the semi-enclosed radio frequency superconducting cavity according to any one of claims 1 to 7, the method comprises: transporting the mixed acid to an acid inlet pipe in the radio frequency superconducting cavity; Covering the mixed acid onto the inner surface of the radio frequency superconducting cavity through the acid inlet pipeline for buffered chemical corrosion; The mixed acid is recovered through a small hole provided in an acid outlet pipeline; High-pressure nitrogen is used to force the acid remaining in the superconducting cavity out of the superconducting cavity.

9. The method according to claim 8, characterized in that The mixed acid is recovered through an acid outlet pipeline, and further comprises: The waste gas in the recovery process is absorbed and treated until it meets the standards before being discharged as tail gas.

10. The method according to claim 8, characterized in that After the acid remaining in the superconducting cavity is pressed out of the superconducting cavity by high-pressure nitrogen, the superconducting cavity is cleaned by pure water.

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