JP2948371B2 - Accelerator tube welding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the joining of an acceleration tube for accelerating charged particles by high frequency power.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view of a typical acceleration tube. The accelerating tube 1 is manufactured by combining the accelerating cells 2 machined from a metal such as copper having good electric conductivity to form an accelerating cavity 3 and continuously joining the accelerating cells 2 in the axial direction. . The accelerating tube 1 is used by evacuating the accelerating cavity 3 to a vacuum. When high frequency power is supplied from the outside, the high frequency power resonates at a constant frequency due to the mechanical shape of each accelerating cavity 3. Then, an electric field for accelerating the charged particles is excited in the accelerating cavity 3 by the high-frequency power having caused resonance. Charged particle beam axis 4
It is accelerated by passing through the accelerating electric field between a and 4b. Incidentally, the electromagnetic field excited in the accelerating cavity 3 is affected not only by the mechanical accuracy of the accelerating cavity 3 but also by the accuracy of the axial assembly between the accelerating cells 2. Is an important issue.

Conventionally, as shown in FIGS. 8A and 8B,
The brazing material 6 is sandwiched between the acceleration cells 5 and heated to a predetermined temperature in a brazing furnace or the like, so that the brazing material 6 is once melted to join the acceleration cells 5. FIG.
FIG. 2B is an enlarged view of a portion X in FIG.

[0004]

However, the brazing material 6
Although a sheet-like material is used, there is a disadvantage that the thickness is not constant and dimensional control is difficult. Further, forming the brazing material 6 into the same shape as the brazing groove 7 of the acceleration cell 5 requires a notch, and as shown in FIG.
Leading to longitudinal dimensional error L ₁ in fabricating the acceleration tube. Further, a gap 9 is generated in the contact surface, and there is a risk that the brazing material 10 melted by heating flows into the acceleration cavity 11. Furthermore, by the brazing material 10 melting and becoming liquid, the frictional force between the acceleration cells decreases, and the acceleration cells slip,
Axial deviation L ₂ is generated, the coaxial degree between accelerating cells may deteriorate.

The present invention has been made in view of the above circumstances, and provides an accelerating tube joining method capable of improving the coaxiality between accelerating cells, improving the dimensional accuracy in the axial direction, and preventing the brazing of the inner surface of the cavity. The purpose is to:

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided an accelerating tube joining method for joining accelerating cells divided into a plurality of parts. An accelerating tube joining method characterized in that after providing a controlled plating film, the accelerating cells are joined to each other by using at least one of heating and pressurizing means.

[0007]

According to the present invention, at the time of accelerating cell bonding,
An accelerating tube with no axial deviation, good dimensional accuracy, and no spotting of the brazing material can be manufactured, and stable acceleration can be performed without giving an unstable electromagnetic field to the beam.

[0008]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. 1A and 1B show an accelerated cell bonding method of the present invention. Here, FIG. 1A is a cross-sectional view of the acceleration cell, and FIG. 1B is an enlarged view of a portion X in FIG. 1A.

In FIG. 1, a contact surface of an acceleration cell 21 is shown.
22 is machined so that the surface becomes smooth on a lathe or the like. Further, the thickness of the plating film 24 made of silver plating or the like is controlled to about several μm on the plating surface 23 processed with a step from the contact surface 22. These are combined as shown in FIG. 2 and heated to a predetermined temperature in the heating furnace 25. If the longitudinal dimension L is measured before heating, the acceleration cell 21
It is easy to determine whether there is a gap between them. In addition, the plating film 24 is melted by heating and works in the same manner as the brazing material to join the acceleration cells 21 to each other, but since the previous measurement confirmed that there was no gap, the brazing material was introduced into the acceleration cavity 26. We can expect that there is no spot. (Example 2)

Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. Here, FIG. 3A is a cross-sectional view of the acceleration cell, and FIG. 3B is an enlarged view of a portion Y in FIG. 3A.

In FIG. 3, as in FIG. 1, the contact surface 32 of the acceleration cell 31 is machined on a lathe or the like so that the surface becomes smooth. Further, a plating film 34 made of silver plating or the like is applied on the plating surface 33 processed with a step from the contact surface 32 to a thickness of about several μm while controlling the film thickness. In the second embodiment, a predetermined pressure is applied to the contact surface 32 of the acceleration cell 31 in the vertical direction in order to perform diffusion bonding between the base materials. At this time, the acceleration cells stacked as shown in FIG.
The area of the contact surface 32 is changed according to the width W of the contact surface so that the contact pressure of the contact surface is constant in each of the 21. A predetermined number of the acceleration cells 31 are vertically stacked and heated and pressurized in a furnace. FIGS. 4A and 4B show the joint at this time. Here, FIG.
3 is an enlarged view of a Z portion in FIG. In this state, heating is started with a temperature and pressure curve as shown in FIG. In step A, since the temperature T ₁ is lower than the melting point of the plating film 34, the plating film 34 does not melt. Further, since the pressure is received only by the contact surface 32, surface pressure P ₁ becomes enough to deform the accelerating cells 31, which upper and lower accelerating cell 31
Are all constant surface pressures. Thus, it can be expected that the amount of deformation of the acceleration cell 31 in the vertical direction due to heat is constant. By maintaining this state for a predetermined time, diffusion bonding at the contact surface 32 between the acceleration cells 31 progresses and is bonded.

Furthermore give temperature T ₂ which plating is melted in step B. The joint at this time is as shown in FIG. At this time, the surface pressure P ₂ between the accelerating cells decreases because the central portion 35 of the accelerating cell 31 comes into contact by experiencing step A, and there is not enough force to deform the base material. Therefore, it can be expected that the amount of deformation in the vertical direction is small. This temperature T
_{In step 2} , the plating film 34 is melted and becomes liquid, but in step A, since the contact surface 32 has already been joined, the plating film 34a does not seep into the cavity 36 and the cells do not slip. No axial displacement between the acceleration cells 31 occurs.

[0013]

As described above in detail, according to the present invention, the dimension in the vertical direction can be controlled by replacing the conventional brazing material with plating, and a high-accuracy accelerating tube can be manufactured. Further, it is not necessary to cut the brazing material between the accelerating cells, which is effective when mass-producing the accelerating tube.

[Brief description of the drawings]

FIG. 1 is a sectional view of an acceleration cell according to a first embodiment of the present invention.

FIG. 2 is a joining diagram of acceleration cells according to the first embodiment of the present invention.

FIG. 3 is a joining diagram of acceleration cells according to a second embodiment of the present invention.

FIG. 4 is a joining diagram of acceleration cells in step A according to the second embodiment of the present invention.

FIG. 5 is a joining diagram of acceleration cells in step B according to the second embodiment of the present invention.

FIG. 6 is a heating temperature and pressure curve diagram according to the second embodiment of the present invention.

FIG. 7 is a cross-sectional view of a typical example for explaining an acceleration tube.

FIG. 8 is a joining diagram of conventional acceleration cells.

FIG. 9 is a view showing various problems in the conventional joining method.

[Explanation of symbols]

21, 31 ... acceleration cell, 22, 32 ... contact surface, 2
3, 33: plating surface, 24, 34: plating film, 25: heating furnace, 26, 36: acceleration cavity,

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shun Kangawa 5007 Itozakicho, Mihara City, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd.Mihara Works Co., Ltd. (72) Inventor Yoshiaki Furusawa 5007 Itozakicho, Mihara City, Hiroshima Prefecture Mitsubishi Heavy Industries Stock (72) Inventor Yasuhiro Fukaya Hiroshima Pref., Hiroshima Pref., Hiroshima Prefecture 4-72 Kanon Shinmachi Hiroshima Research Institute Mitsubishi Heavy Industries, Ltd.Hiroshima Research Laboratories (72) Inventor Minoru Hiroshima Pref., Hiroshima Pref. No. Hiroshima Tsukuba, Mitsubishi Heavy Industries, Ltd. (72) Inventor Hiromi Tsune No. 4, 22-22 Kannon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Prefecture Mitsubishi Heavy Industries, Ltd. Hiroshima Research Center (56) References JP-A-57-96500 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05H 7/00-9/04 B23K 20/00-20/26

Claims (1)

(57) [Claims] In an accelerating tube joining method for joining a plurality of divided acceleration cells, a groove having a step is formed on a joint surface of the acceleration cell, and a plating film having a controlled thickness is provided in the groove. An accelerating tube joining method, wherein the accelerating cells are joined to each other by using at least one of heating and pressurizing means.