JPH0955300A - Manufacture of superconducting high-frequency acceleration cavity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a high performance superconductive high-frequency acceleration cavity, by manufacturing an outer halved cavity to form a cylinder by a superconducting seat to insert the cylinder into the inside of the outer halved cavity, and expanding the cylinder in the inner surface of the outer halved cavity to be fixed as an inner side cavity. SOLUTION: At first, raw material composed of a forging is machined to form an outer halved cavity 9. Two cavities 9 are oppositely arranged to join and integrate divided parts by arc welding and electron beam welding, etc., to form an outer side cavity 10. After that, a high purity seat, composed of superconductive material such as Nb or Pb, etc., is formed cylindrically to insert a cylinder 11, wherein the divided parts are joined, into the inside of the cavity 10. An inner cavity is formed on the inner surface of the cavity 10, while expanding the cylinder 11 by external force, to degas the space of the cavity to be into vacuum to sealedly weld both end parts. Next, when the cylinder 11 and the cavity 10 are joined by an HIP device, the cylinder 11 is uniformly diffused, joined, and integrated on the inside surface of the cavity 10 as an inner cavity to manufacture a superconductive high-frequency acceleration cavity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a superconducting high frequency accelerating cavity used in a charged particle beam accelerator.

[0002]

2. Description of the Related Art An accelerator is a device for accelerating charged particles such as electrons, protons and ions to a high energy state of several billion electron volts (several GeV) by electromagnetic force. Has been developed for the study of.

However, in recent years, by utilizing synchrotron radiation (called SOR light) generated in the tangential direction of the orbit of an electron propagating in a vacuum at a substantially light speed when the orbit is bent by a deflection magnetic field, We are expanding the scope of application to a wide range of science and technology fields such as life science, such as ultra-LSI microfabrication (lithography) and material research.

A high frequency acceleration cavity is provided in the beam line of the accelerator in order to accelerate charged particles and replenish the energy lost as SOR light. FIG. 11 shows an example of a conventional high-frequency accelerator, which accelerates charged particles,
A high-frequency accelerating cavity 2 is inserted in a beam duct 1 of the accumulating circular accelerator. The high frequency oscillated by the high frequency oscillator 3 is supplied to the high frequency acceleration cavity 2 through the waveguide 4 and the antenna 5.

The high frequency supplied to the high frequency acceleration cavity 2 resonates to generate a high electric field E between both ends 1a of the beam duct 1 to accelerate the charged particle beam 6. In this case, when a high electric field E is generated, a circulating current flows through the inner surface of the high frequency acceleration cavity 2, and since this current is a high frequency current, it flows through the skin depth corresponding to the material of the inner surface of the high frequency acceleration cavity 2,
Causes Joule loss.

By the way, in order to obtain a high electric field necessary for accelerating the charged particle beam 6 in the normal conducting high frequency accelerating cavity made of copper, aluminum or the like, the Joule loss mentioned above becomes extremely large and compensates for this Joule loss. Therefore, a high-power high-frequency oscillator 3 capable of supplying a large amount of high-frequency power is required.

However, there is no high-frequency oscillator that can supply such high-frequency power. In addition, there is a problem in cooling the high frequency acceleration cavity 2, and there is a limit to the application of the normal conduction high frequency acceleration cavity.

Therefore, it is conceivable to form the high-frequency acceleration cavity with a superconducting material having an electric resistance of approximately 0Ω so that Joule loss does not occur even if a current flows through the inner surface of the high-frequency acceleration cavity 2.

Although the field of use of superconducting high-frequency accelerating cavities is wide-ranging, especially for charged particle beam accelerators, limited electric power is being used for large electron storage rings, which are being planned and constructed around the world in recent years. The realization of superconducting high-frequency accelerating cavities is desired to obtain electrons with the highest possible energy in a limited space.

Conventionally, as a method for manufacturing a superconducting high frequency acceleration cavity, for example, a method disclosed in Japanese Patent Laid-Open No. 1-231300 is known. This manufacturing method is shown in FIG.
Acceleration cavity 7 made of aluminum alloy as base metal
Then, the Nb film 8 is formed inside the acceleration cavity 7 by sputtering to manufacture a superconducting high frequency acceleration cavity.

[0011]

As described above, in the conventional method for manufacturing the superconducting high frequency accelerating cavity, the inside of the accelerating cavity 7 formed of the aluminum alloy is sputtered with N.
Since the b film 8 is formed, there are problems that the thickness of the Nb film 8 is not uniform, the purity of the Nb film 8 is low, and the superconductivity may be deteriorated.

The present invention has been made to solve the above-mentioned problems, and it is a high-performance and economical superconducting high-frequency acceleration that prevents deterioration of superconducting characteristics, is easy to manufacture, and contributes to reduction of manufacturing cost. An object is to provide a method for manufacturing a cavity.

[0013]

In order to achieve the above object, the present invention is to manufacture a superconducting high frequency accelerating cavity by the following steps. The invention corresponding to claim 1 is:
A superconducting high frequency accelerating cavity for imparting energy to a charged particle beam, wherein the inner surface of the outer cavity having a good thermal conductive material as a base material and facing the beam is formed of an inner cavity made of a superconducting material. In the above, a step of manufacturing an outer cavity, a step of forming an inner cylinder with a sheet of superconducting material, and inserting the cylinder into the outer cavity, and inflating the cylinder on the inner surface of the outer cavity, And a step of fixing as a body.

The invention corresponding to claim 2 is a high frequency accelerating cavity for applying energy to a charged particle beam, wherein an inner surface of the outer cavity having a good heat conducting material as a base material and facing the beam is made of a superconducting material. In the superconducting high-frequency acceleration cavity formed of the inner cavity, a step of forming an outer half-split cavity divided into two so as to have a split portion at approximately the center of the outer cavity in the beam acceleration axis direction; Steps of arranging the half cavities facing each other and welding the divided parts to form an integrated outer cavity, forming a cylinder with a sheet of superconducting material, and inserting the cylinder into the outer cavity And then inflating the cylinder on the inner surface of the outer cavity to fix it as an inner cavity.

The invention according to claim 3 is the invention according to claim 1 or 2, wherein a cylinder formed of a superconducting material is formed on the inner surface of the outer cavity formed of a good heat conducting material by HIP (hot isotropy). It is inflated and fixed by the pressure bonding method.

According to a fourth aspect of the present invention, in the invention according to the first or second aspect, a cylinder formed of a superconducting material is inflated by an explosive bonding method on the inner surface of the outer cavity formed of a good heat conducting material. Fix it.

According to a fifth aspect of the invention, in the invention according to the first or second aspect, a cylinder formed of a superconducting material is formed on the inner surface of the outer cavity formed of a good heat conducting material by a hydraulic forming joining method. It is inflated and brought into close contact, and then heated and pressed to fix.

The invention corresponding to claim 6 is a superconducting high frequency accelerating cavity in which an inner surface of a cavity made of a good heat conducting material as a base material is formed of a superconducting material, and a sheet of the superconducting material is drawn or a die is used. Forming the inner half-split cavity divided into two parts so as to have a split part at approximately the center of the cavity in the beam acceleration axis direction, and dividing the two inner half-split cavities so as to face each other. Welding the parts to form an integrated inner cavity, and forming the outer half cavity with a good thermal conductive material so as to have a split part at the center of the cavity in the beam acceleration axis direction. When,
Stacking the two outer half cavities on the outer side of the inner cavity,
The method includes the steps of welding the divided portions to form an integrated outer cavity, and fixing the superconducting material portion of the inner cavity and the good heat conducting material portion of the outer cavity.

The invention according to claim 7 is the superconducting high frequency acceleration cavity according to the invention according to claim 6, in which an outer cavity formed of a good heat conducting material is stacked on an outer side of an inner cavity formed of a superconducting material. In, the superconducting material portion of the inner cavity and the good heat conducting material portion of the outer cavity are fixed by the HIP bonding method.

The invention corresponding to claim 8 is a superconducting high frequency accelerating cavity in which an inner surface of an accelerating cavity made of a good heat conducting material as a base material is made of a superconducting material, and a sheet of the superconducting material is drawn or shaped. A step of forming an inner half-cavity which is divided into two parts having a divided part at approximately the center of the cavity in the beam acceleration axis direction, and similarly machining two good heat conductive materials, Forming an outer half-split cavity divided into two parts so as to have a split part at approximately the center of the cavity in the beam acceleration axis direction by forging or using a die; A step of producing two half cavities by superimposing and joining each of the half cavities, and a step of arranging these two half cavities facing each other and joining the divided parts to integrate them. Equipped with.

Therefore, according to the inventions corresponding to claims 1 to 5, the elongation percentage of copper or aluminum is about 40%.
Therefore, the half-cavity can be easily molded by molding using a mold or machining. Further, unlike sputtering or the like, there is no need to manufacture electrodes, jigs for installing electrodes, and mirror finishing of the inner surface of the outer cavity, which can contribute to reduction in manufacturing cost. Further, since the superconducting material on the inner surface of the outer cavity has a high purity and a uniform thickness, it is possible to prevent deterioration of the superconducting characteristics.

According to the inventions corresponding to claims 6 to 8, since the superconducting material previously processed into the shape of the cavity is fixed to the good thermal conductive material, the aspect ratio (the diameter of the cavity along the central axis is It is possible to manufacture a superconducting high-frequency accelerating cavity having a large ratio of the maximum part to the minimum part).

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment for explaining a method for manufacturing a superconducting high-frequency acceleration cavity according to the present invention, in which (a) is a half cavity forming step,
(B) is a welding integration process, (c) is a cylindrical insertion step,
(D) shows the adhesion process to the inner surface, respectively.

First, in step (a), the outer half-cavity 9 is formed by machining a material made of a forged product. in this case,
As a base material of the outer half-split cavity 9, copper, aluminum, or the like, which is a good heat conductive material and excellent in workability, is used.

Next, in step (b), the two outer half cavities 9 are arranged so as to face each other, and the divided portions are joined by arc welding, electron beam welding, brazing or the like to be integrated to form the outer cavity 10. Form. Then, in step (c), a high-purity sheet made of a superconducting material such as Nb or Pb is formed into a cylindrical shape, and a cylinder 11 having divided portions joined by, for example, electron beam welding is placed inside the outer cavity 10 described above. insert.

Finally, in step (d), the cylinder 11 is
An external force is applied to the inner cavity of the outer cavity 10 so that the inner cavity of the outer cavity 10 is intimately contacted with and bonded to the inner surface of the outer cavity 10. Here, the step (c) and the step (d) will be specifically described with reference to FIG.

In FIG. 2A, the cylinder 11 is inserted into the outer cavity 10, and then the space 12 between the cylinder 11 and the outer cavity 10 is vacuum degassed, and both ends are seal-welded. This method is carried out by electron beam welding or the like capable of vacuum degassing. In the figure, 1
3 shows a seal weld.

After the seal welding, the HIP device 14 is used to join the cylinder 11 and the outer cavity 10. In the HIP device 14 shown in FIG. 2B, isotropic pressure of high temperature and high pressure, for example, 800
In an atmosphere of 1000 ° C / cm ^{2 at} ℃, an isotropic pressure is applied to the cylinder 11 and the outer cavity 10 in the direction indicated by the arrow 15, and the cylinder 11 is deformed with the lapse of time, and finally, as shown in FIG.
As shown in FIG. 5, the cylinder 11 is uniformly joined to the inner surface of the outer cavity 10 by diffusion bonding as an inner cavity to be integrated with each other to manufacture a superconducting high-frequency acceleration cavity.

Next, the function and effect of the above-described first embodiment will be described. Copper, aluminum, etc. have high thermal conductivity, and their elongation rate is about 40% higher than that of Nb.
It has good machinability. Therefore, the outer half cavity 9 can be easily and accurately formed by forging or machining.

After the forming process, the outer half cavity 9 is integrated by a joining method such as welding to manufacture the outer cavity 10. Separately Nb
A high-purity sheet made of a superconducting material such as Pb or Pb is formed into a cylindrical shape, and a divided portion is joined by, for example, electron beam welding to produce a cylinder 11, which is heated in a high-temperature and high-pressure gas atmosphere for HIP joining, By pressurizing, atoms such as Nb and Pb diffuse into each other in the outer cavity 10 made of copper, aluminum or the like through the bonding interface to bond and integrate.

Therefore, the outer cavity 1 made of copper, aluminum, etc.
Cylinder 1 made of superconducting material such as Nb or Pb on the inner surface of 0
A superconducting high frequency acceleration cavity in which 1 is fixed as the inner cavity is obtained. Also, with this method, unlike sputtering, etc., the electrodes are manufactured, the jigs for installing the electrodes are manufactured, and the outer cavity 1
Since it is not necessary to mirror-finish the inner surface of No. 0, it can contribute to the reduction of manufacturing cost. Furthermore, N on the inner surface of the outer cavity 10
Since the inner cavity having high purity and a uniform thickness is fixed to b, deterioration of superconducting characteristics can be prevented.

In the above embodiment, the outer cavity 10 is used.
Although the divided portions of the two outer half-split cavities 9 are joined and integrated with each other, the outer cavity 10 may be integrally manufactured by hydraulic molding or electroforming instead.

Further, although the divided portion is also joined to the cylinder 11 which is the inner cavity, it may be manufactured as an integral body by drawing or machining instead of this. Further, when the outer cavity 10 and the inner cavity are diffusion-bonded, an active metal such as titanium may be interposed.

A second embodiment of the present invention will be described with reference to FIG. In the second embodiment, as shown in FIG. 3, a robust restraint jig 16 is attached to the outside of the outer cavity 10,
A contact plate 17 is arranged inside the cylinder 11, and an explosive 18 for explosive joining is provided in the center thereof. By exploding the explosive 18, the joint surface between the cylinder 11 and the outer cavity 10 can be firmly joined via the metal jet.

The inner surface of the outer cavity 10 and the outer surface of the cylinder 11, which are joint surfaces, are first subjected to finish processing so that explosive joining is possible. After the explosive joining, the contact plate 17 is removed and the restraint jig 16 is removed, whereby a superconducting high frequency accelerating cavity having a predetermined shape as shown in FIG. 1D is obtained.

Next, the function and effect of the second embodiment as described above will be described. Similar to the first embodiment, the outer cavity 1 in which the outer half cavity 9 is integrated by a joining method such as welding.
0 and a cylinder 11 in which a high-purity sheet made of a superconducting material such as Nb or Pb is separately formed into a cylindrical shape and joined,
A cylinder made of a superconducting material such as Nb or Pb on the inner surface of the outer cavity 10 without causing deformation of the outer cavity 10 protected by a robust restraint jig 16 by detonating an explosive placed inside the cylinder 11. Only 11 will collide.

At the point of collision between the inner surface of the outer cavity 10 and the cylinder 11, both metals behave like a viscous fluid due to a very large deformation speed and high pressure, and a jet of metal is generated in front of the point of collision. Since the jet removes the oxide film on the metal surface and the gas adsorption layer, the resulting clean surface adheres under high pressure, and the outer cavity 10 made of copper or aluminum and the cylinder made of a superconducting material such as Nb or Pb. 11
Are firmly joined and integrated. In particular, in this method, a sound jet can be obtained by the metal jet despite the joining in the atmosphere.

In the explosive bonding of this embodiment, the outer cavity 1 is
Since 0 and the cylinder 11 can be joined without heating, deterioration of the material due to softening of the outer cavity 10 and the cylinder 11 can be avoided. Therefore, a superconducting high frequency accelerating cavity having a high structural strength in which a superconducting material such as Nb or Pb is formed on the inner surface of the outer cavity 10 such as copper or aluminum can be obtained.

Further, this method, unlike sputtering, does not require the production of electrodes, the production of jigs for installing the electrodes, and the mirror finishing of the inner surface of the outer cavity, which contributes to a reduction in production cost. Further, since Nb on the inner surface of the outer cavity has a high purity and a uniform thickness, it is possible to prevent deterioration of superconducting characteristics.

A third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the cylinder 11 is arranged inside the outer cavity 10, the seal jigs 19 are arranged at both ends of their central axes, and the liquid 20 is inserted and pressurized therein. The cylinder 11 is gradually deformed by increasing the liquid pressure inside the cylinder, and is finally brought into close contact with the inside of the outer cavity 10. Further, by keeping the temperature of the liquid at 100 ° C., the outer cavity 10 and the cylinder 11 can be joined by mutual diffusion. Further, when it is difficult to obtain the bonding under the conditions of the temperature and the pressure of the liquid, although not shown, a heater may be arranged outside the outer cavity 10 to preheat and heat to a temperature at which the bonding is possible. is there.

The inner surface of the outer cavity 10 and the outer surface of the cylinder 11, which are joint surfaces, are first subjected to finish processing so that they can be joined by mutual diffusion. Next, the function and effect of the above-described third embodiment will be described.

As in the first and second embodiments, the outer cavity 1 in which the outer half cavity 9 is integrated by a joining method such as welding.
0 and a cylinder 11 in which a high-purity sheet made of a superconducting material such as Nb or Pb is separately formed into a cylindrical shape and joined,
By filling the inside of the cylinder 11 with a high-temperature and high-pressure liquid, the cylinder 11 follows the shape of the inner surface of the outer cavity 10 so that atoms such as copper and aluminum and atoms such as Nb and Pb are diffusion bonded through the bonding interface. The superconducting high frequency accelerating cavities can be obtained by joining and integrating.

Further, in this method, large-sized and expensive equipment as shown in the first embodiment is not used, and a HIP device which is severe in terms of safety and installation conditions is not used, and in particular, approval for high-pressure gas control is not required. It is possible to use a diffusion bonding apparatus of high temperature and high pressure which is not legally restricted.

Further, since the joining apparatus is easy to introduce and handle, and the large-sized joining apparatus is also easy to manufacture, it is possible to cope with a large-sized accelerating cavity device.
Besides, there are the same effects as those of the first and second embodiments.

A fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 (a) shows a forming process of the inner half cavity,
(B) is a welding integrated process, (c) is a double process of accelerating cavities, (d) is a fixing process of an outer cavity and an inner cavity.

First, in the step (a), the plate material which is the material of the inner cavity 21 is formed into a trumpet shape by drawing or spin processing. In this case, the superconducting material Nb or Pb is used as the base material of the inner cavity 21.

Next, in step (b), the two inner half cavities 21 are
The inner cavity 21 is manufactured by arranging a and 21b facing each other and joining the divided parts by arc welding, electron beam welding, brazing or the like to integrate them.

Then, in step (c), the outer half cavities 22a and 22b are superposed on the outer side of the inner cavity 21. In this case, as the base material of the outer half cavities 22a and 22b, copper, aluminum or the like, which is a good heat conductive material and excellent in workability, is used. The outer half cavities 22a and 22b are joined together by, for example, arc welding, electron beam welding, or brazing to integrate them, so that the inner portion is made of a superconducting material and the outer portion is made of a good heat conducting material. Heavy superconducting RF acceleration cavity 2
3 is made.

Finally, in step (d), the superconducting material on the inside and the good heat conducting material on the outside are fixed in the acceleration cavity.
Next, the function and effect of the above-described fourth embodiment will be described.

According to the manufacturing method of the present embodiment, the inner cavity 21 made of a superconducting material such as Nb or Pb is not machined from the cylinder as in the above-mentioned embodiments, but is drawn from a plate material. A predetermined inner cavity 21 can be manufactured by forming a trumpet shape by spin processing or the like, and then abutting and welding the trumpet-shaped inner half cavities 21a and 21b. Furthermore, the inner half cavity 21 is integrated with the outer half cavity 22a,
22b is attached, the outer half cavities 22a and 22b are butted to each other and welded to integrate the outer cavity 22. In this way, the superconducting material of the inner cavity 21 and the outer cavity 22
A superconducting high-frequency acceleration cavity can be obtained by fixing the good heat-conducting material.

In this embodiment, the inner half cavities 21a and 21b made of a superconducting material such as Nb or Pb are not machined from the cylinder as in the above-mentioned embodiment, but are preliminarily machined into a cavity shape. Since the superconducting material is fixed to the good heat conducting material, a superconducting high frequency accelerating cavity having a large aspect ratio can be manufactured. Further, since the processing rate is small, heat treatment for removing strain after the forming processing is not required.

Therefore, a highly accurate acceleration cavity can be manufactured, and the number of manufacturing steps can be shortened because the number of steps is small. Other,
The same effects as those of the first, second and third embodiments can be obtained.

A fifth embodiment of the present invention will be described with reference to FIG. In the fifth embodiment, the outer half cavities 22a and 22b made of a good heat conducting material are stacked on the outer side of the inner cavity 21 made of the superconducting material used in the fourth embodiment, and then the outer half halves are stacked. As shown in FIG. 6, a double superconducting high frequency acceleration cavity 23 is formed by joining the joint surfaces of the cavities 22a and 22b by electron beam welding or the like to form the outer cavity 22 by a high temperature and high pressure isotropic pressure device. It is put in a certain HIP device 14, and the superconducting material of the inner cavity 21 and the good heat conducting material of the outer cavity 22 are diffusion-bonded and integrated in a gas atmosphere of high temperature and high pressure.

As the joining conditions, the joining temperature is lower than the melting point of the good thermal conductive material, for example, 1000 ° C. or lower for copper and 500 ° C. or lower for aluminum, and the pressure is 100 kgf / mm.
^If the holding time is ² or more and the holding time is 30 minutes or more, the superconducting material of the inner cavity 21 made of Nb or Pb and the good heat conducting material of the outer cavity 22 made of copper or aluminum are firmly diffusion-bonded. .

The HIP device 1 as in the present embodiment
In the diffusion bonding using No. 4, the bonding surface of the superconducting material of the inner cavity 21 and the good thermal conductive material of the outer cavity 22 shown in the first embodiment and FIG. Processing such as deaeration has been performed in advance.

Next, the function and effect of the fifth embodiment as described above will be described. According to the manufacturing method of the present embodiment, the superconducting material such as Nb or Pb of the inner cavity 21 and the good thermal conductive material of the outer cavity 22 made of copper or aluminum are, for example, 1000 ° C. or less if copper. 5 for aluminum
At a joining temperature of 00 ° C or less, a pressure of 100 kgf / mm ² or more,
Diffusion bonding is firmly performed under a bonding condition of holding time of 30 minutes or more. In particular, the plate thickness of the superconducting material of the inner cavity 21 made of Nb, Pb, etc. is a fraction of the thickness of the good heat conducting material of the outer cavity 22 made of copper, aluminum, etc. Therefore, in diffusion bonding using a HIP device, due to isotropic pressing, the superconducting material of the inner cavity 21 made of Nb, Pb, or the like becomes an inner shape of the good thermal conductive material of the outer cavity 22 made of copper, aluminum, or the like. follow.

In particular, in this method, the inner cavity 21 made of a superconducting material is preliminarily formed into a predetermined shape by welding by shaping a plate material into a trumpet shape by drawing or spin processing. Similarly, the shape of the inner surface of the outer half cavity is also finished to follow the shape of the outer surface of the inner cavity.

Therefore, it is easy from the prior art to perform diffusion bonding using a HIP device after vacuum sealing. In addition, since the good thermal conductive material of the outer cavity 22 made of copper, aluminum or the like is made of a relatively thick plate, and its machining accuracy is finished into a predetermined shape, accuracy is required as an acceleration cavity. The dimensional accuracy of the inner cavity 21 made of a superconducting material such as Nb or Pb can be as high as designed. Further, it is possible to manufacture a superconducting high frequency acceleration cavity having a large aspect ratio.

A sixth embodiment of the present invention will be described with reference to FIG. FIG. 7 (a) shows the two inner halves shown in FIG. 5 (b) before the superconducting material of the inner cavity and the good heat conducting material of the outer cavity shown in the fourth embodiment are fixed. Cavity 21
a and 21b are arranged to face each other and the divided portions are joined by arc welding, electron beam welding or the like to be integrated, and a paste-like brazing material 24 is applied to the outer surface of the inner cavity 21, and then the outer half cavity 22a. , 22b are overlapped, and these joints are joined by, for example, electron beam welding or the like to form the outer cavity 22, and the double superconducting high-frequency cavity 23 is placed in the vacuum furnace 25 and vacuum brazed to form the inner cavity 21. By fixing the outer cavities 22 to be integrated with each other, a double superconducting high-frequency acceleration cavity 23 having a superconducting material on the inner side and a good heat conducting material on the outer side is formed.

The vacuum brazing of this double superconducting high-frequency acceleration cavity 23 is not more than the melting point of a good heat conductive material, for example, about 1000 ° C. for copper and 500 ° C. for aluminum.
By performing vacuum brazing using the front and rear temperatures and a brazing material that can be brazed, the superconducting material of the inner cavity 21 made of Nb, Pb, etc. and the good heat conducting material of the outer cavity 22 made of copper, aluminum, etc. Firmly vacuum brazed.

The vacuum brazing of the present embodiment is a method of applying a paste-like brazing material, but the present embodiment is not limited to the method of applying a paste-like brazing material.
A sheet-shaped brazing material is arranged on the outer surface of the inner cavity 21,
Alternatively, vacuum brazing can be performed by inserting a linear brazing material into a brazing material groove provided on the outer surface of the inner cavity 21. Although vacuum brazing is performed in this embodiment, a similar acceleration cavity can be manufactured by a brazing method in the atmosphere.

Next, the function and effect of the above-described sixth embodiment will be described. According to the manufacturing method of the sixth embodiment, the superconducting material of the inner cavity 21 made of Nb, Pb, etc. and the good thermal conductive material of the outer cavity 22 made of copper, aluminum, etc. have a melting point of the good thermal conductive material. Hereafter, for example, copper is 1000
By performing vacuum brazing using a brazing material that can be brazed at a temperature of approximately 500 ° C.
Vacuum brazing is performed through the brazing material.

In particular, in this manufacturing method, the inner cavity 21 made of a superconducting material is preliminarily formed into a predetermined shape by welding the plate material into a trumpet shape by drawing or spin processing. Similarly, the outer half cavity 22a made of a good heat conducting material,
The inner surface shape of 22b is also finished to follow the outer peripheral surface shape of the inner cavity 21. In this case, vacuum brazing these via a brazing material is also easy from the prior art.

Therefore, since the good thermal conductive material of the outer cavity 22 made of copper, aluminum or the like is composed of a relatively thick plate, and its processing accuracy is finished into a predetermined shape,
The dimensional accuracy of the inner cavity 21 made of a superconducting material such as Nb or Pb that requires precision as an acceleration cavity can be as high as designed. In addition, it is possible to fabricate a superconducting high-frequency acceleration cavity having a large apest ratio.

The seventh embodiment of the present invention will be described with reference to FIG. As shown in FIG. 8A, before the superconducting material of the inner cavity 21 and the good thermal conductive material of the outer cavity 22 shown in the fourth embodiment are fixed, two pieces shown in FIG. The inner half cavities 21a and 21b of the above are arranged opposite to each other, and the divided portions are joined by arc welding, electron beam welding or the like, and the paste-like solder 26 is applied to the outer surface of the inner cavity 21 integrated with the divided parts. As shown in FIG. 8 (b), the outer half cavities 22a, 22b
The superconducting high frequency accelerating cavities 23, which are formed by joining these joints by electron beam welding or the like to form the outer cavities 22, are placed in an atmospheric furnace 27 or a gas atmosphere furnace, and the temperature at which the paste-like solder melts. The inner cavity 21 is made of a superconducting material and the outer cavity 22 is made of a good heat conducting material to form a double superconducting high-frequency accelerating cavity 23 by heating up to and soldering them together.

Next, the function and effect of the seventh embodiment described above will be described. According to the manufacturing method of the seventh embodiment, for example, tin-lead solder is used for soldering, and zinc chloride or ammonium chloride is used for the flux, so that the temperature is relatively low around 200 ° C. It is possible to join at temperature, there is no deterioration of material strength due to the heat of the outer cavity material of good heat conducting material such as copper or aluminum, and it is possible to perform uniform heating by using a gas atmosphere furnace etc. Since the joining can be performed evenly, a sound joining can be obtained.

In this case, the superconducting material of the inner cavity 21 made of Nb, Pb or the like and the good heat conducting material of the outer cavity 22 made of copper or aluminum are firmly soldered. In particular, in the present manufacturing method, the inner cavity 21 made of a superconducting material is preliminarily formed into a predetermined shape by welding the plate material into a trumpet shape by drawing or spin processing. It is also easy to solder these from the conventional technology.

Therefore, since the good thermal conductive material of the outer cavity 22 made of copper, aluminum or the like is composed of a relatively thick plate, and its processing accuracy is finished into a predetermined shape,
The dimensional accuracy of the inner cavity 21 made of a superconducting material such as Nb or Pb, which requires precision as an acceleration cavity, can be as high as designed. Further, it is possible to manufacture the superconducting high frequency acceleration cavity 23 having a large aspect ratio.

The eighth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 9A, before the superconducting material of the inner cavity 21 and the good heat conducting material of the outer cavity 22 shown in the fourth embodiment are brought into close contact with each other, two inner halves shown in FIG. The cavities 21a and 21b are arranged so as to face each other, and the divided portions are arc welded.
A thermosetting adhesive 28 is applied to the outer surface of the inner cavity 21 that is joined and integrated by electron beam welding or the like, and then, as shown in FIG.
As shown in (b), the outer half cavities 22a and 22b are superposed, and the double superconducting high frequency accelerating cavity 23 is joined to the outer cavity by joining these joints by, for example, electron beam welding or the like to form a high temperature furnace 29. It is heated to a temperature at which the adhesive hardens, and is bonded and integrated to form a double superconducting high-frequency acceleration cavity in which the inner cavity 21 is made of a superconducting material and the outer cavity 22 is made of a good heat conducting material. The body 23 is manufactured.

Next, the function and effect of the eighth embodiment as described above will be described. According to the manufacturing method of the eighth embodiment, for example, if a thermosetting adhesive is used, bonding can be performed at a relatively low temperature, and the material strength of the good thermal conductive material made of copper, aluminum or the like due to the heat of the outer cavity is high. Can be joined without deterioration. In particular, in the present manufacturing method, the inner cavity 21 made of a superconducting material is preliminarily formed into a predetermined shape by welding a plate material into a trumpet shape by drawing or spin processing. Similarly, the inner surface shapes of the outer half cavities 22a and 22b are also finished to follow the outer peripheral surface shape of the inner cavity 21. In this case, it is said that it is easy to join them via a welding agent also from the prior art.

Therefore, since the good thermal conductive material of the outer cavity 22 made of copper, aluminum or the like is composed of a relatively thick plate, and its processing accuracy is finished into a predetermined shape,
The dimensional accuracy of the superconducting material such as Nb or Pb of the inner cavity 21, which requires accuracy as an acceleration cavity, is as high as designed. Further, it is possible to manufacture the superconducting high frequency acceleration cavity 23 having a large aspect ratio.

FIG. 10 shows the ninth embodiment of the present invention.
This will be described below. FIG. 10 (a) is a forming process for the inner half-cavity, (b) is a forming process for the outer half-cavity, (c) is a double process for the inner and outer half-cavities, and (d) is an inner and outer side. This is the process of combining the halves. Further, (e) is a step of joining the inner and outer half cavities and then joining the other inner and outer half cavities produced in the same manner. here,
A superconducting material such as Nb or Pb is used as the base material of the inner half cavity, and copper or aluminum which is a good heat conductive material and excellent in workability is used as the base material of the outer half cavity. The manufacturing procedure will be described below in the order of steps.

First, in step (a), the inner half-cavity 21a is formed by press working, spin working, or the like. Similarly, in the step (b), the outer half cavity 22a is formed by press working, spin working, or the like.

Next, in step (c), these inner half cavities 21a and outer half cavities 22a are polymerized to deaerate the joint surfaces, and then seal welding 13 is performed in order to maintain a vacuum state. Then, in step (d), these are joined by diffusion joining using the HIP device 14 to manufacture the half-accelerated cavity 30a.

Further, the double half acceleration cavity 30a joined in the step (d) and the double half acceleration cavity 30b manufactured in the same manner are arranged to face each other, and the divided parts are butted. In step (e), the HIP device 14 is used to join and combine them by diffusion bonding to fabricate a double superconducting high-frequency acceleration cavity 31 in which the inner cavity is made of a superconducting material and the outer cavity is made of a good heat conducting material. .

For example, in diffusion bonding using the HIP device 14, the bonding surface needs to be in a vacuum atmosphere. Therefore, as a specific method thereof, the surface of the joint surface is made uneven, and after cleaning, the inner surface is seal-welded with a YAG laser or the like, and then the joint surface of the outer peripheral portion is vacuum seal-welded by electron beam welding or the like. The purpose of vacuum sealing is HIP device 1
This is because the high temperature and high pressure gas at the time of diffusion bonding using No. 4 does not enter the bonding surface.

In this case, the penetration of the welding may be a depth of several millimeters. In addition, the use of the YAG laser for the seal welding of the inner surface also makes it possible to insert a fiber for guiding the beam of the YAG laser from several ports even if the half-accelerating cavities 30a and 30b are arranged to face each other. It is a factor. Further, the joining condition is a double superconducting high-frequency acceleration cavity 31 in which the inner cavity is made of a superconductive material and the outer cavity is made of a good heat conductive material. It is possible to select an appropriate range for the joining within the temperature range below the melting point of the material and by changing the pressure back and forth.

In the ninth embodiment, HIP is used.
It is diffusion bonding using the device 14, but the inner half cavity 21 is
The joining method of the a, 21b and the outer half cavities 22a, 22b is not limited to the diffusion joining using the HIP device 14, and the diffusion joining, brazing, and soldering by the hot press not using the HIP device 14 can be performed. Alternatively, a double superconducting high frequency accelerating cavity 31 in which the inner cavity is made of a superconducting material and the outer cavity is made of a good heat conducting material can be manufactured by a joining method such as bonding.

Next, the function and effect of the ninth embodiment as described above will be described. According to the manufacturing method of the ninth embodiment, the inner cavity 21 of the superconducting material made of Nb, Pb, etc. and the outer cavity 22 of the good heat conducting material made of copper, aluminum, etc.
Since each of them is joined in the state of a half-cavity, it has high processing accuracy and dimensional accuracy before joining, and also because of ease of assembly, diffusion bonding using the HIP device 14, diffusion bonding by hot pressing, and brazing. In the joining method by soldering, bonding, or the like, the half-acceleration cavities 30a and 30b, which are joined bodies of the inner half-halves and the outer half-cavities, can be obtained. The half-accelerating cavities that have been joined with high precision are further joined together by the same joining method to form Nb having a predetermined shape.
A double superconducting high-frequency accelerating cavity 31 is obtained, which includes an inner cavity 21 made of a superconducting material such as Pb and Pb and an outer cavity 22 made of a good heat conducting material such as copper and aluminum.

Therefore, the double layer is composed of a plate having a relatively thick good thermal conductive material of the outer cavity 22 made of copper or aluminum and a plate having a relatively thin superconducting material of the inner cavity 21 made of Nb or Pb. The superconducting high-frequency accelerating cavity of (1) can obtain a highly precise dimensional accuracy of the inner cavity 21 made of a superconducting material such as Nb or Pb, which is required to have high precision as designed. Further, it is possible to manufacture a superconducting high frequency acceleration cavity having a large aspect ratio.

[0081]

As described above, according to the present invention, it is possible to manufacture a high-performance and economical superconducting high-frequency accelerating cavity that can prevent deterioration of superconducting characteristics, can be manufactured easily, and can contribute to reduction of manufacturing cost. A method can be provided.

[Brief description of drawings]

1 (a), (b), (c) and (d) are explanatory views showing a first embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

2A and 2B are explanatory views specifically showing the same embodiment.

FIG. 3 is an explanatory view showing a second embodiment of a method for manufacturing a superconducting high frequency acceleration cavity according to the present invention.

FIG. 4 is an explanatory view showing a third embodiment of a method for manufacturing a superconducting high frequency acceleration cavity according to the present invention.

5 (a), (b), (c) and (d) are explanatory views showing a fourth embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

FIG. 6 is an explanatory view showing a fifth embodiment of a method for manufacturing a superconducting high frequency acceleration cavity according to the present invention.

7A and 7B are explanatory views showing a sixth embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

8A and 8B are explanatory views showing a seventh embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

9A and 9B are explanatory views showing an eighth embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

10 (a), (b), (c) and (d) are explanatory views showing a ninth embodiment of a method of manufacturing a superconducting high frequency accelerating cavity according to the present invention.

FIG. 11 is an explanatory diagram showing a configuration example of a conventional high-frequency accelerator.

12 (a) and 12 (b) are explanatory views showing an example of a method for manufacturing a conventional superconducting high-frequency acceleration cavity.

[Explanation of symbols] 1 ... Beam duct, 2 ... High-frequency acceleration cavity, 3 ... High-frequency oscillator, 4 ... Waveguide, 5 ... Antenna, 6 ... Charged particle beam, 7 ... Aluminum alloy Acceleration cavity, 8 ... N
b membrane, 9, 22a, 22b ... Outer half-split cavity, 10, 2
2 ... Outer cavity, 11 ... Cylinder, 12 ... Space, 13 ...
... Seal weld, 14 ... HIP device, 15 ... Isotropic pressure, 16 ... Restraint jig, 17 ... Contact plate, 18 ... Explosive,
19 ... Sealing jig, 20 ... Liquid, 21 ... Inner cavity, 21a, 21b ... Inner half cavity, 23 ... Superconducting high frequency acceleration cavity, 24 ... Brazing material, 25 ... Vacuum furnace Two
6 ... Solder, 27 ... Atmosphere furnace, 28 ... Adhesive, 29 ...
... High temperature furnace, 30a ... Half acceleration cavity, 30b ... Half acceleration cavity, 31 ... Superconducting high frequency acceleration cavity, 32 ... Seal welding, 33 ... HIP equipment, 34 ... Half acceleration cavity Torso
35 ... Accelerating cavity.

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[Procedure amendment]

[Submission date] December 8, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction contents]

10 (a), (b), (c), (d) and (e) are explanatory views showing a ninth embodiment of a method for manufacturing a superconducting high frequency accelerating cavity according to the present invention.

Claims (8)

[Claims] 1. A high-frequency accelerating cavity for imparting energy to a charged particle beam, wherein the inner surface of the outer cavity, which is made of a good heat conducting material and faces the beam, is formed by an inner cavity made of a superconducting material. In the superconducting high frequency acceleration cavity, a step of manufacturing an outer cavity, a step of forming an inner cylinder with a sheet of superconducting material, and inserting the cylinder into the outer cavity, and forming a cylinder on the inner surface of the outer cavity. And a step of inflating and fixing the inner cavity as a superconducting high-frequency acceleration cavity. 2. A high frequency accelerating cavity for imparting energy to a charged particle beam, wherein an inner cavity facing the beam of an outer cavity made of a good heat conductive material is formed by an inner cavity made of a superconducting material. In the superconducting high-frequency acceleration cavity, a step of forming an outer half-split cavity divided into two so as to have a split portion at approximately the center of the outer cavity in the beam acceleration axis direction, and the two half-split cavities are opposed to each other. Arranging and welding the divided parts to integrate them into an outer cavity, forming a cylinder with a sheet of superconducting material, and inserting the cylinder into the outer cavity, And a step of inflating the cylinder on an inner surface to fix the cylinder as an inner cavity, the method for manufacturing a superconducting high-frequency acceleration cavity. 3. A cylinder formed of a superconducting material is HIP (hot isostatically pressed) on the inner surface of the outer cavity formed of a good heat conducting material.
The method for producing a superconducting high frequency accelerating cavity according to claim 1 or 2, characterized in that the superconducting high frequency accelerating cavity is expanded and fixed by a joining method. 4. The superconducting high-frequency acceleration according to claim 1, wherein a cylinder formed of a superconducting material is inflated and fixed to the inner surface of the outer cavity formed of a good heat conducting material by an explosive bonding method. Manufacturing method of cavity. 5. A cylinder formed of a superconducting material is inflated and brought into close contact with the inner surface of the outer cavity formed of a good heat conducting material by a hydraulic forming joining method, and then heated and pressed to be fixed. The method for manufacturing a superconducting high-frequency acceleration cavity according to claim 1 or 2. 6. In a superconducting high-frequency acceleration cavity in which the inner surface of a cavity made of a good heat-conducting material as a base material is formed of a superconducting material, a sheet of the superconducting material is formed by drawing or using a mold, and a beam acceleration shaft is formed. Forming an inner half-split cavity divided into two so as to have a split portion substantially at the center of the cavity in the direction, and arranging the two inner half split cavities to face each other and welding the split portions to integrate them. And a step of forming an outer half-split cavity divided into two with a good heat conductive material so as to have a split portion at the center of the cavity in the beam acceleration axis direction, A step of stacking the two outer half cavities on the outer side and welding the divided portions to form an integrated outer cavity; and a step of forming a superconducting material portion of the inner cavity and a good heat conducting material of the outer cavity. A method of manufacturing a superconducting high frequency accelerating cavity, comprising the step of fixing parts. 7. A superconducting high-frequency accelerating cavity in which an outer cavity formed of a good heat conducting material is superposed on an outer side of an inner cavity formed of a superconducting material, and good heat of the superconducting material portion of the inner cavity and the outer cavity. 7. The method for manufacturing a superconducting high frequency accelerating cavity according to claim 6, wherein the conductive material portion is fixed by the HIP bonding method. 8. A superconducting high frequency accelerating cavity in which an inner surface of an accelerating cavity made of a good thermal conductive material as a base material is formed of a superconducting material, and a beam of the superconducting material is formed by drawing or using a die for beam acceleration. The process of forming an inner half-split cavity divided into two so as to have a split portion at approximately the center of the cavity in the axial direction, as well as using two good heat conductive materials by machining, forging, or a die. Forming and molding the outer half-split cavity divided into two so as to have a split portion at approximately the center of the cavity in the beam acceleration axis direction, and each of the inner half split cavity and the outer half split cavity. The method further comprises a step of manufacturing the two half cavities by superimposing and joining them, and a step of arranging these two half cavities to face each other and joining the divided parts to integrate them. Method for manufacturing superconducting high frequency acceleration cavity.