CN114710872A - A detachable nested composite superconducting cavity - Google Patents

Abstract

The invention relates to a detachable nested composite superconducting cavity, which comprises: at least one superconducting inner cavity is arranged, and the whole superconducting inner cavity is arranged in a vacuum environment; a first non-superconducting housing, one end of which is provided with a first connection sealing flange, the inner side of which is provided with a first semicircular groove; a second non-superconducting housing, one end of which is provided with a second connecting sealing flange, and the inner side of which is provided with a second semicircular groove; after the first connecting sealing flange and the second connecting sealing flange are installed in a matched mode, the first semicircular groove and the second semicircular groove are matched to form a sealed containing cavity, the containing cavity is used for containing the superconducting inner cavity in a vacuum environment, and the outer wall of the superconducting inner cavity is in contact with the inner wall of the containing cavity. The superconducting cavity has greatly reduced processing and treating difficulty and greatly reduced maintenance cost. The invention can be applied in the technical field of radio frequency superconduction.

Description

A detachable nested composite superconducting cavity

technical field

The invention relates to the technical field of radio frequency superconductivity, in particular to a detachable nested composite superconducting cavity.

Background technique

The radio frequency superconducting cavity is a kind of electromagnetic resonant cavity. Compared with the normal conducting cavity, it has the advantages of high quality factor and high acceleration gradient. It is the core component of the particle accelerator. However, the superconducting materials used in it, such as metal niobium, cost Expensive and difficult to process. Also, the thermal conductivity of superconducting materials is generally low, and decreases with decreasing purity. At the same time, the interior of the superconducting cavity must be evacuated during testing and operation, and the exterior of the superconducting cavity sometimes needs to be placed in atmospheric pressure, and the cavity will withstand a high atmospheric pressure difference. In order to achieve the required mechanical strength, thicker materials need to be used and cannot The selection of materials with high purity, high thermal conductivity but low mechanical strength makes the existing superconducting cavity generally have poor thermal conductivity and poor operation stability. In order to solve this problem, some composite cavities, such as copper-niobium composite cavities formed by pressing copper-niobium composite plates, are made, and a thinner superconducting layer is used inside and a copper layer with high external thermal conductivity is used to improve the overall cavity. heat conduction effect. However, this kind of composite cavity is complicated to process, and because the melting point of copper on the outer wall is about 1000 °C lower than that of niobium, the inner niobium layer cannot be subjected to heat treatment such as high-temperature annealing, which limits the further improvement of the performance of this composite superconducting cavity. And the cost of this kind of composite cavity is more expensive than that of pure niobium cavity.

In addition, when the resonator is running, its internal electromagnetic field is not uniformly distributed in space, and its inner surface current only has a high value at the fixed position of the resonator, so it is not necessary to use ultra-low RF surface resistance at all positions. guide material. In addition, the beam tube is also welded on the general superconducting cavity during processing. After forming, a sealing device is added to the beam tube side. The sealing ring of the required device also needs superconducting material, and generally only expensive and difficult Processed metal indium wire seal. As mentioned earlier, most of the beam tube is free of surface currents induced by the RF field, so the use of superconducting materials is not necessary.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a detachable nested composite superconducting cavity, the superconducting cavity processing and processing difficulty are greatly reduced, and the maintenance cost is also greatly reduced.

In order to achieve the above purpose, the present invention adopts the following technical scheme: a detachable nested composite superconducting cavity, which includes: a superconducting inner cavity, at least one superconducting cavity is provided, and the whole of the superconducting inner cavity is placed in a vacuum environment inside; a first non-superconducting shell, one end of which is provided with a first connecting sealing flange, and the inner side of the first connecting sealing flange is provided with a first semicircular groove; a second non-superconducting shell, one end of which is provided with a The second connection sealing flange, the inner side of the second connection sealing flange is provided with a second semicircular groove; after the first connection sealing flange is installed with the second connection sealing flange, the first connection sealing flange The semicircular groove cooperates with the second semicircular groove to form a sealed accommodating cavity, and the accommodating cavity is the vacuum environment for accommodating the superconducting inner cavity, and the The outer wall of the superconducting inner cavity is in contact with the inner wall of the accommodating cavity.

Further, at least the inner wall surface of the superconducting cavity is made of niobium plating, niobium tritin or magnesium boride, or the whole of the superconducting cavity is made of high-purity metal niobium.

Further, the first connection sealing flange and the second connection sealing flange are connected by screws.

Further, both the first non-superconducting shell and the second non-superconducting shell are made of non-superconducting materials.

Further, both the first non-superconducting casing and the second non-superconducting casing are made of metal copper, aluminum alloy or high-performance ceramic material with high thermal conductivity.

Further, the other ends of the first non-superconducting casing and the second non-superconducting casing are provided with beam tubes and conventional resonant cavity components.

Further, connecting flanges are provided at the ends of the beam tubes of the first non-superconducting shell and the second non-superconducting shell, and the connecting flanges are connected to the external refrigerator cold head or The cooling liquid transmission pipeline is connected to cool the first non-superconducting shell and the second non-superconducting shell, and then conduct conduction cooling to the accommodating cavity and the superconducting inner cavity in it.

Further, the nested composite superconducting cavity further includes at least one double-headed casing;

Both ends of the double-headed housing are respectively provided with a third connection sealing flange, and the inner side of the third connection sealing flange is provided with a third semicircular groove; The first semi-circular groove and the second semi-circular groove cooperate to form sealed accommodating cavities respectively; each of the accommodating cavities is provided with a superconducting inner cavity.

Further, the double-headed housing is made of non-superconducting material.

Further, between the third connection sealing flanges between the adjacent double-headed housings, between the third connection sealing flange and the first connection sealing flange, and the second connection sealing method The flanges are connected by screws.

The present invention has the following advantages due to taking the above technical solutions:

1. The nested composite superconducting cavity structure adopted in the present invention reduces the required volume of the superconducting part and simplifies the shape, which can reduce the cost of the superconducting cavity and transfer the mechanical strength requirements to inexpensive and easy-to-process non-superconducting materials On the premise of not reducing the performance, the processing and processing difficulty of the superconducting cavity is greatly reduced.

2. Because of the nested structure, the superconducting inner cavity part of the present invention can be installed after heat treatment alone. When the superconducting cavity R&D test and comparison experiment proves that it is damaged or its performance is reduced, only the corresponding part can be replaced, so that the maintenance cost of the cavity is also reduced. Greatly reduced.

3. In the present invention, multiple accommodating cavities are formed by double-headed shells, and welding is not required between multiple double-headed shells, and there is no need for surface current flow between multiple superconducting cavities placed in a vacuum state. Welding, you can also arbitrarily assemble, increase or decrease the number.

Description of drawings

1 is a schematic diagram of the overall structure of a disassembled nested composite superconducting cavity in Embodiment 1 of the present invention;

2 is an exploded schematic view of a dismantled nested composite superconducting cavity in Embodiment 1 of the present invention;

Fig. 3 is the front view of Fig. 1;

Fig. 4 is the side view of Fig. 1;

Fig. 5 is C-C sectional view in Fig. 4;

Fig. 6 is the top view of Fig. 1;

Fig. 7 is B-B sectional view in Fig. 6;

8 is a schematic diagram of the overall structure of a detachable nested composite superconducting cavity provided with two double-headed casings in Embodiment 2 of the present invention;

9 is an exploded schematic view of a dismantled nested composite superconducting cavity provided with two double-headed casings in Embodiment 2 of the present invention;

Fig. 10 is the sectional view of Fig. 8;

11 is a schematic structural diagram of a double-headed housing in Embodiment 2 of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

The invention proposes a disassembled nested composite superconducting cavity, the superconducting cavity is composed of two parts, including a superconducting inner cavity of superconducting material and an outer shell made of non-superconducting material. The structure used in the present invention reduces the required volume of the superconducting part and simplifies the shape, which can reduce the cost of the superconducting cavity, and transfer the mechanical strength requirements to the cheap and easy-to-process non-superconducting materials. The difficulty of processing and processing the whole cavity is greatly reduced; and because of the nested structure, the superconducting part can be installed after heat treatment alone. When the superconducting cavity is researched and tested, it can only be replaced when it is damaged or its performance is reduced. The maintenance cost is also greatly reduced.

Example 1:

In this embodiment, a detachable nested composite superconducting cavity is provided. In this embodiment, as shown in FIGS. 1 to 7 , the nested composite superconducting cavity includes:

At least one superconducting inner cavity 1 is provided, and the superconducting inner cavity 1 is placed in a vacuum environment as a whole; since the superconducting inner cavity 1 is in a vacuum environment as a whole, its interior is a complete vacuum environment, and the outer wall is a vacuum environment, but it is in a vacuum environment. There is no atmospheric pressure difference between the inner and outer walls of the superconducting cavity 1.

The first non-superconducting shell 2 is provided with a first connection sealing flange 3 at one end, and a first semicircular groove 4 is provided on the inner side of the first connection sealing flange 3;

The second non-superconducting housing 5 is provided with a second connection sealing flange 6 at one end, and the inner side of the second connection sealing flange 6 is provided with a second semicircular groove 7;

After the first connection sealing flange 3 is installed with the second connection sealing flange 6, the first semicircular groove 4 cooperates with the second semicircular groove 7 to form a sealed accommodating cavity, and the accommodating cavity is For the vacuum environment for accommodating the superconducting inner cavity 1 , the outer wall of the superconducting inner cavity 1 is in contact with the inner wall of the accommodating cavity.

When in use, since the superconducting inner cavity 1 is placed in a vacuum environment as a whole, the cavity wall does not have to bear the huge difference in atmospheric pressure inside and outside, so it is not necessary to deliberately select hard but low-purity and low thermal conductivity materials for mechanical strength. The excessively high thickness of 2-3 mm of the ordinary superconducting cavity greatly improves the thermal conductivity of the superconducting part, which is beneficial to improve the performance and operation stability of the cavity.

In the above embodiment, at least the inner wall surface of the superconducting cavity 1 is made of materials such as niobium plating, niobium tritin, magnesium boride or other superconductors, or the overall superconducting cavity 1 is made of high purity (high thermal conductivity). made of niobium metal.

In the above-mentioned embodiment, the superconducting inner cavity 1 does not include a structure with a low surface current distribution position such as a beam tube, so it is not necessary to use a complex sealing means of superconducting material, so the invention reduces the volume of the superconducting part, which is expensive. The amount of superconducting materials is greatly reduced, the difficulty of machining and post-processing is greatly reduced, and the production cost is reduced. For example, the rare pure niobium superconducting cavity welded beam tube uses electron beam welding, and the welding of the beam tube and the flange is made of niobium welded stainless steel. In this embodiment, these expensive processing techniques are changed to a copper integrally formed shell and a beam tube, and the welding of the beam tube and the flange is changed to mature and inexpensive copper-welded stainless steel, and it is not necessary to weld a beam every time a cavity is made. Flow tube and flange, there is no need to spend expensive price to build a flow tube.

In the above-mentioned Embodiment 1, the first connection sealing flange 3 and the second connection sealing flange 6 are fixedly connected by screws. After the sealing connection, the superconducting inner cavity 1 made of the superconducting material can be placed in a vacuum environment without atmospheric pressure difference during operation.

In the above embodiment 1, the first non-superconducting shell 2 and the second non-superconducting shell 5 are made of non-superconducting materials, preferably, metal copper, aluminum alloy or high-performance ceramic materials with high thermal conductivity are used. production. And the other ends of the first non-superconducting casing 2 and the second non-superconducting casing 5 are provided with beam tubes 8 and other conventional resonant cavity components with low surface current.

Preferably, connecting flanges 9 are provided at the ends of the beam tubes 8 of the first non-superconducting casing 2 and the second non-superconducting casing 5, and the connecting flanges 9 are connected to the external refrigerator cold head or cooling liquid through the connecting flanges 9. The transmission pipes are connected to cool the first non-superconducting shell 2 and the second non-superconducting shell 5, and then conduct conduction cooling to the accommodating cavity and the superconducting inner cavity 1 in it.

Example 2:

The disassembled nested composite superconducting cavity provided in this embodiment has basically the same structure as the disassembled nested composite superconducting cavity provided in Embodiment 1, the difference is that the superconducting cavity in this embodiment The number of inner cavities 1 is set to be two or more. In addition to the structures included in Embodiment 1, at least one double-headed housing 10 is included, as shown in FIGS. 8 to 11 .

The double-headed housing 10 is used as a connecting head, and its two ends are respectively provided with a third connecting sealing flange 11 , a third semicircular groove 12 is provided on the inner side of the third connecting sealing flange 11 , and the third semicircular groove 12 at both ends is provided The grooves 12 are respectively matched with the first semicircular groove 4 and the second semicircular groove 7 to form sealed accommodating cavities; each accommodating cavity is provided with a superconducting inner cavity 1 .

In the above embodiment, the double-headed housing 10 is made of non-superconducting material.

In the above embodiment, a plurality of double-head housings 10 can be provided, and the third connecting sealing flanges 11 of adjacent double-head housings 10 are connected to each other to form a plurality of accommodating cavities for accommodating the superconducting inner cavity 1 . And each accommodating cavity is a vacuum environment.

In the above-mentioned embodiment, the third connection sealing flange 11 between the adjacent double-head housings 10 and the third connection sealing flange 11 and the first connection sealing flange 3 and the second connection sealing flange 6 are connected. All are connected by screws.

During use, the number of accommodating cavities can be arbitrarily increased or decreased by the number of double-headed housings 10 provided. Since there is no flow of surface current between the plurality of superconducting cavities 1 placed in a vacuum state, welding is also not required. Since the connection of each part does not need to be welded, the processing cost of expensive welding is saved.

To sum up, when the present invention is used, a non-superconducting part is used to cover the superconducting part, and other components of a conventional resonator with low surface current such as a beam tube are included, and an additional flange sealing port is added as required, so as to The superconducting part is easy to be nested and sealed.

Since the superconducting inner cavity 1 of the present invention is in direct contact with the accommodating cavity, the heat generated by the loss can be conducted from the superconducting inner cavity 1 made of superconducting material to the first non-superconducting shell 2 and the second non-superconducting shell of the non-superconducting shell. Second, the non-superconducting shell 5 does not need to worry about the problem of the decrease of thermal conductivity. At the same time, the superconducting cavity 1 does not contain a beam tube, and there is no need to use complex sealing means of superconducting materials. Therefore, the invention reduces the volume of the superconducting part, greatly reduces the required superconducting materials, and greatly reduces the difficulty of machining and post-processing. , reducing the production cost; its mechanical stability is greatly improved, and for the coating cavity, the problem of the film breaking and falling off due to the deformation of the substrate can also be avoided. Moreover, due to the separation of the inner and outer parts, the implementation of R&D test comparison tests, or the cavity is damaged and the performance cannot be restored, only the corresponding parts need to be replaced, and the rest can be reused, which also greatly reduces the processing and maintenance costs.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. A collapsible nested composite superconducting cavity, comprising:

at least one superconducting inner cavity is arranged, and the whole superconducting inner cavity is arranged in a vacuum environment;

a first non-superconducting housing, one end of which is provided with a first connection sealing flange, the inner side of which is provided with a first semicircular groove;

a second non-superconducting housing, one end of which is provided with a second connecting sealing flange, and the inner side of which is provided with a second semicircular groove;

after the first connecting sealing flange and the second connecting sealing flange are installed in a matched mode, the first semicircular groove and the second semicircular groove are matched to form a sealed containing cavity, the containing cavity is used for containing the superconducting inner cavity in a vacuum environment, and the outer wall of the superconducting inner cavity is in contact with the inner wall of the containing cavity.

2. The dismantlable nested composite superconducting cavity of claim 1, wherein at least an inner wall surface of the superconducting inner cavity is made of niobium, niobium tri-tin or magnesium boride, or the superconducting inner cavity is made of niobium with high purity as a whole.

3. The collapsible nested composite superconducting cavity of claim 1, wherein the first connecting sealing flange and the second connecting sealing flange are fixedly connected by screws.

4. The collapsible nested composite superconducting cavity of claim 1, wherein the first non-superconducting enclosure and the second non-superconducting enclosure are made of non-superconducting material.

5. The collapsible nested composite superconducting cavity of claim 4, wherein the first non-superconducting enclosure and the second non-superconducting enclosure are made of metallic copper, aluminum alloy or high performance ceramic material.

6. The collapsible nested composite superconducting cavity of claim 1, wherein the other end of the first non-superconducting enclosure and the second non-superconducting enclosure are provided with a beam tube and a conventional resonant cavity component.

7. The collapsible nested composite superconducting cavity of claim 6, wherein a connecting flange is disposed at an end of the beam pipe of each of the first non-superconducting shell and the second non-superconducting shell, and the connecting flange is connected to an external refrigerator cold head or a coolant transmission pipeline to cool the first non-superconducting shell and the second non-superconducting shell, and further to conduct and cool the accommodating cavity and the superconducting inner cavity therein.

8. The collapsible nested composite superconducting cavity of any one of claims 1 to 7, wherein the nested composite superconducting cavity further comprises at least one double-ended shell;

the two ends of the double-end shell are respectively provided with a third connecting sealing flange, and the inner side of each third connecting sealing flange is provided with a third semicircular groove; the third semicircular grooves at two ends are respectively matched with the first semicircular groove and the second semicircular groove to respectively form a sealed accommodating cavity; each accommodating cavity is internally provided with one superconducting inner cavity.

9. The collapsible nested composite superconducting cavity of claim 8, wherein the double-ended shell is made of a non-superconducting material.

10. The collapsible nested composite superconducting cavity of claim 8, wherein the third joint sealing flange between adjacent double-ended enclosures and the third joint sealing flange are screwed to the first joint sealing flange and the second joint sealing flange.

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