JP3335773B2 - Beam duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accelerator such as a synchrotron for accelerating electrons and ions, and more particularly to a beam duct used in a portion where the starting speed of a bending magnet is high.

[0002]

2. Description of the Related Art In an accelerator such as a synchrotron for accelerating electrons and ions, a beam duct is provided in a portion where a rising speed of a bending electromagnet is high when low incident energy is used with high energy.

[0003] For this reason, a large eddy current is generated in the beam duct by the magnetic flux from the bending electromagnet, and the beam is bent by the magnetic field formed by the eddy current and deviates from a target orbit.

Therefore, as a conventional beam duct, in order to suppress the eddy current, a bellows formed into a high-resistance, thin-walled structure or a connection bellows formed by welding is used.

FIG. 4 shows the structure of the molded bellows 12 , and connection flanges 1 are attached to both ends thereof.
FIG. 5 shows a configuration of the welding bellows 10, and connection flanges 1 are attached to both ends thereof.

However, it is difficult to manufacture a beam duct using the above-described molded bellows or welded bellows when a long distance is required. Therefore, conventionally, as shown in FIG. 6, the connecting flange 1 is attached by welding or the like to one end of a thin-walled vacuum vessel 7 in which reinforcing ribs 8 are attached by brazing at appropriate intervals on the outer peripheral surface. One end of the bellows duct 6 is welded to the other end of the vacuum vessel 7 via a holding plate 5 for adjustment, and the other end is attached to the connection flange 1 by welding.

[0007]

Generally, whether the beam duct is thick or thin, the beam duct expands and contracts in the direction of the beam axis during the entire assembly. In addition, baking is performed to increase the degree of vacuum. At this time, there is expansion and contraction due to heat generated in the duct.

Therefore, the expansion and contraction of the duct is absorbed by the bellows 6 joined to the end of the duct, so that the external force acting on the connection flange side is reduced. However, in the beam duct having such a configuration, there are many welded portions for connecting the adjustment press plate 5, the vacuum vessel 7, the connection flange, and the like for the expansion and contraction adjustment to the bellows portion. There are many.

When the beam energy is large and the eddy current generated in the beam duct is large, the vacuum vessel 7
The adjusting press plate 5 is attached to one end or both ends of the above, but from the viewpoint of suppressing the generation of eddy current, there is a problem in the mounting method and the reinforcing method of the adjusting press plate.

[0010] The large number of welding points and the provision of the adjusting holding plate have various problems in improving the quality of the beam duct. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a beam duct in which a vacuum vessel can be incorporated and baking can be easily performed to improve reliability.

[0011]

According to the present invention, a beam duct is constituted by the following means to achieve the above object. The invention according to claim 1 is a beam duct comprising a thin-walled cylindrical vacuum vessel through which electron and ion beams are passed, reinforcing ribs attached to the outer peripheral surface thereof, and connection flanges provided at both ends. A bellows duct for adjusting the length is provided at at least one end of the bellows duct, and this bellows duct is formed integrally with the vacuum container . Annular groove and the insulation
Between the ring-shaped ceramic and this ring-shaped ceramic.
The ceramic presser that presses in the axial direction of the
A first sealing metal between the annular ceramic and the annular groove.
And the ring-shaped ceramic and the ceramic
A second sealing metal is interposed between the mic presser and the mic holder.

According to a second aspect of the present invention, a length adjusting pressing plate is attached to a boundary surface between the vacuum vessel and the bellows duct with a silver braze. According to a third aspect of the present invention, there is provided a beam duct in which a reinforcing rib is attached to an outer peripheral surface of a thin-walled cylindrical vacuum vessel through which a beam of electrons or ions passes, wherein at least one end of the vacuum vessel is adjusted in length. A bellows duct is provided, and the bellows duct is formed integrally with the vacuum vessel, and a ring-shaped insulator is provided at the end of the bellows duct inside the connection flange and attached .
Sealing metal is applied to the connection between the ring-shaped insulator and the connection flange.
It is interposed and provides insulation in the radial direction of the connection flange.

[0013]

According to the beam duct of the present invention corresponding to the first and second aspects, when the bellows duct is attached to the connection flange via an insulating material, the bellows duct is formed in the annular groove formed in the connection flange by a ceramic press. Since sealing metal is inserted into both axial end surfaces of the ceramic pressed in the axial direction to provide insulation in the axial direction, it occurs at the connection between the bellows duct and the connection flange when the magnetic field is started by the bending electromagnet. The eddy current and the current generated by the beam can be cut off. Further, since the ceramic is held inside the connection flange via the sealing metal, welding such as vacuum sealing can be easily performed.

Further, since the adjustment holding plate is brazed for the purpose of only adjusting the length of the bellows, the thickness in the axial direction can be reduced, and the generation of eddy current due to the magnetic field of the bending electromagnet can be suppressed. It becomes possible.

In the beam duct according to the third aspect of the invention, not only the same operation and effect as described above can be obtained, but also the ring-shaped insulator joined to the end of the bellows duct is connected to the connection flange. , Eddy current due to the influence of the magnetic field of the bending electromagnet, image current generated by the beam, and the like can be effectively cut off.

In addition, in the beam duct according to the first to third aspects of the present invention, since the inner surface area of the vacuum vessel is reduced, advantages such as easy vacuum evacuation can be obtained.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of a beam duct according to the present invention. In FIG. 1, reference numeral 7 denotes a thin wall made of a non-magnetic material having a high electric resistance (for example, 0.2 to 0.5 mm).
A reinforcing rib 8 is attached to the outer peripheral surface of the vacuum vessel 7 by brazing so as to be able to withstand a pressure difference between the inside and the outside at an appropriate interval. In this case, a ring-shaped bulging portion for fixing the reinforcing rib 8 is formed on the outer peripheral surface of the vacuum vessel 7.

A connection flange 1 is attached to one end of the vacuum vessel 7 by welding, and a bellows duct 6 for absorbing axial elongation due to baking is attached to the other end.
Are integrally formed, and an adjustment pressing plate 5 is attached to a boundary surface between the vacuum vessel 7 and the bellows duct 6.

In this case, the bellows duct 6 provided at the end of the vacuum vessel 7 is formed by processing at the same time when the vacuum vessel 7 is formed. Also, a holding plate 5 for adjusting the expansion and contraction of the bellows duct 6 is attached by silver brazing at the same time when the vacuum vessel 7 is formed.

On the other hand, as shown in FIG. 2, the connection flange 1 attached to the end of the bellows duct 6 has an annular groove 1a formed on the bellows duct side of a hole provided at the center, and a ring-shaped groove is formed in the annular groove 1a. The ceramic 3 is inserted, the sealing metal 2 is inserted from both axial end surfaces of the ceramic 3 to the inner peripheral surface of the hole, and a ceramic retainer 11 is provided on the opening side of the annular groove 1a. Annular groove 1a
A disk-shaped insulating material 4 is inserted with the sealing metal 2 extending toward the bellows duct side as a central axis. Then, an end of the bellows duct 6 is attached to the insulating material 4 via a metal joint 9.

In this case, the bellows duct 6 and the joint 5 are welded, and the joining of the ceramic 3 and the ceramic retainer 11 with the sealing metal 2 can be simultaneously formed and brazed. Therefore, by attaching the bellows duct 6 to the connection flange 1 in this manner, the bellows duct 6 is coupled to the connection flange 1 in an axially insulated state.

In the beam duct having such a configuration, a thin-walled vacuum vessel 7 and a bellows duct 6 which are brazed with reinforcing ribs 8 on the outer peripheral surface at appropriate intervals are simultaneously processed and integrally formed. Therefore, it is possible to prevent a problem that occurs when the vacuum vessel 7 and the bellows duct 6 are joined by welding as in the related art.

Therefore, the present invention can be applied to a large or small particle acceleration ring using a vacuum container. In particular, in the case of miniaturization, since the polarities of the bending electromagnets become small, a design corresponding to the curvature of the vacuum vessel 7 is required. However, a small ring-shaped for fixing the reinforcing rib 8 attached to the vacuum vessel 7 is required. Since the bulging portion exists, bending can be performed freely.

In addition, when the vacuum vessel 7 is formed, the pressing plate 5 for adjusting the expansion and contraction of the bellows duct 6 can be simultaneously attached with silver brazing. When the bellows duct 6 is attached to the connection flange 1 via the insulating material 4, the connection flange The sealing metal 2 is inserted into both axial end faces of the ceramic 3 pressed in the axial direction by the ceramic press 11 into the annular groove 1a formed in the inside 1 and joined by brazing to provide axial insulation. Therefore, an eddy current generated at a connection portion between the bellows duct 6 and the connection flange 1 at the time of starting the magnetic field by the bending electromagnet and a current generated by the beam can be cut off.

Further, since the ceramic 3 is provided inside the connection flange 1, welding such as vacuum sealing can be easily performed. FIG. 3 is a cross-sectional view showing a second embodiment of the beam duct according to the present invention. Here, differences from FIG. 1 will be described.

In the second embodiment, as shown in FIG. 3, a bellows duct 6 formed integrally with a vacuum vessel 7 is formed.
Is welded to the connection flange 1 by welding, and both ends in the axial direction are held in the annular holes 1b provided on the outer periphery of the center hole of the connection flange 1 by the sealing metal 2 and held. 3 is provided with insulation in the radial direction.

With such a configuration, the same operation and effect as those of the first embodiment can be obtained. In the first embodiment and the second embodiment, the case where the bellows duct is integrally formed at one end of the vacuum vessel 7 is described. However, the bellows duct is integrally formed at both ends of the vacuum vessel. You may do so.

[0028]

As described above, according to the present invention, the vacuum container can be easily assembled and baked , and the deflection electromagnetic wave can be easily obtained.
Bellows duct and connection flange when starting magnetic field with stone
Current generated by eddy current or beam at the connection with
A highly reliable beam duct that can cut off the beam.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a beam duct according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a joint between a connection flange and a beam duct in the embodiment.

FIG. 3 is a sectional view of a beam duct showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing a beam duct using a conventional bellows duct.

FIG. 5 is a sectional view showing a beam duct using a conventional welding bellows duct.

FIG. 6 is a sectional view showing a beam duct in which a conventional vacuum vessel and a bellows duct are joined.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Connection flange 2, ... Sealing metal, 3 ... Ceramic, 4 ... Insulating material, 5 ... Adjusting press plate, 6 ... Bellows duct, 7 ... Vacuum container, 8 ... Reinforcement rib, 9 ... Joint.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-326191 (JP, A) JP-A-5-57380 (JP, A) JP-A-64-82500 (JP, A) JP-A-62-1982 136798 (JP, A) JP-A-3-289099 (JP, A) JP-A-6-124793 (JP, A) JP-A-6-5393 (JP, A) JP-A-63-175501 (JP, A) JP-A-5-275199 (JP, A) JP-A-3-192699 (JP, A) JP-A 5-23498 (JP, U) JP-A 63-99700 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05H 7/14 H05H 13/04

Claims (3)

(57) [Claims] 1. A beam duct having a reinforcing rib attached to an outer peripheral surface of a thin-walled cylindrical vacuum vessel through which an electron or ion beam passes and connection flanges provided at both ends, wherein at least one end of the vacuum vessel is provided. Is provided with a bellows duct for adjusting the length, the bellows duct is formed integrally with the vacuum vessel, and the bellows duct is connected to the connection flange via an insulating material, and a ring formed on the connection flange is provided.
A ring-shaped ceramic is inserted between the groove and the insulating material.
A ceramic presser that presses the ring ceramic in the axial direction
Inserted between the ring-shaped ceramic and the annular groove
The first sealing metal is interposed in the
A second sealing metal between Mick and the ceramic presser
A beam duct, characterized in that a beam duct is inserted . 2. The beam duct according to claim 1, wherein
A beam duct, wherein a length adjusting pressing plate is attached to a boundary surface between the vacuum vessel and the bellows duct by attaching a silver braze. 3. A beam duct in which a reinforcing rib is attached to an outer peripheral surface of a thin-walled cylindrical vacuum vessel through which an electron or ion beam passes, wherein a bellows duct for adjusting the length is provided at least at one end of the vacuum vessel. The bellows duct is formed integrally with the vacuum vessel, and a ring-shaped insulator is provided inside the connection flange at the end of the bellows duct, and the ring-shaped insulator is connected to the connection flange.
A beam duct in which a sealing metal is inserted into a continuation portion to provide insulation in a radial direction of a connection flange.