JPH08264299A - Insertion light source - Google Patents

Abstract

PURPOSE: To make the inside of a vacuum chamber possible to keep in the most suitable state for an electron beam to proceed, and generate radiant light efficiently by allowing no emission of gas from a magnet even if the vacuum chamber is pressure-reduced down to a high vacuum state. CONSTITUTION: Inside a vacuum chamber 4 incorporated in an electron storage ring or a linear accelerator, an insertion light source is provided so that a pair of magnets rows 3 composed of plural magnets 2 is arranged so as to sandwich the passing position of an electron beam, and magnets 2 composing the magnets rows 3 are arranged so that the magnets 2 of different polarities face to each other as sandwiching the passing position of the electron beam and a magnetic field facing from the downside to the upside of the vacuum chamber 4 and a magnetic field facing from the upside to the downside of the vacuum chamber 4 are alternately formed. The exposed faces of respective magnets rows 3 are coated by sealing members 17 made of stainless steel thin plate material, and the outer edge portions of the sealing members 17 are airtightly fixed to holders 5 supporting the magnets rows 3.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an insertion light source.

[0002]

2. Description of the Related Art When an electron moving at a speed close to the speed of light is bent in its traveling direction by a magnetic field or an electric field, an electromagnetic wave (light) called radiated light is emitted in the tangential direction of the orbit of the electron.

In recent years, research and development have been conducted on an insertion light source such as an undulator device provided in a linear portion of an electron storage ring or a linear accelerator, as a means for generating high-intensity radiated light.

FIG. 7 shows the principle of the insertion light source.
In this insertion light source, a plurality of permanent magnets 2 of the same shape are formed on both outer sides of a vacuum chamber 1 having a hollow structure which is incorporated in an electron storage ring or a linear accelerator and in which an electron beam e advances.
A pair of magnet rows 3 and 3 are arranged.

The above vacuum chamber 1 is SUS316L.
It is made of non-magnetizable material such as (stainless steel).

The permanent magnets 2 forming the magnet arrays 3 and 3 are such that the permanent magnets 2 having different polarities face each other across the vacuum chamber 1 and the one side surface 1a to the other side surface 1 of the vacuum chamber 1.
The magnetic field m ₁ directed to the direction b perpendicular to the traveling direction of the electron beam e and the other side surface 1b of the vacuum chamber 1 to the one side surface 1
The magnetic fields m ₂ are arranged so as to alternate with the magnetic fields m ₂ which are oriented orthogonally to the traveling direction of the electron beam e.

The above vacuum chamber 1 is SUS316L.
It is formed of a non-magnetized material such as (stainless steel), and inside the vacuum chamber 1, a magnetic field m ₁ directed horizontally from one side surface 1a to the other side surface 1b and a magnetic field directed horizontally from the other side surface 1b to the one side surface 1a. and m ₂ are generated alternately in the traveling direction of the electron beam e.

When the emitted light X is generated by the insertion light source shown in FIG. 7, the inside of the electron storage ring in which the vacuum chamber 1 is incorporated, the linear accelerator, or the like is depressurized to a high vacuum state, and then the electron generator is generated. The electron beam e is emitted toward the inside of the vacuum chamber 1 by the above.

Then, the electron beam e receives the Lorentz force due to the influence of the magnetic fields m ₁ and m ₂ described above, and travels in the vacuum chamber 1 while meandering in the vertical direction. As a result, the electron beam e The radiated light X is generated in the tangential direction of the trajectory of the electron beam e at the location where the trajectory is bent.

In the insertion light source, the closer the magnet arrays 3 and 3 are to each other, the stronger the magnetic fields m ₁ and m ₂ acting on the electron beam e are. Since electromagnetic waves are included in the radiated light X, in recent years, as shown in FIGS.
An insertion light source in which magnet rows 3 and 3 are arranged inside is used.

A vacuum chamber 4 incorporated in an electron storage ring, a linear accelerator or the like comprises a chamber body 4a having a substantially cylindrical shape, and a connecting pipe 4b at the center fixed to one end and the other end of the chamber body 4a. It is composed of perforated disk-shaped end plate portions 4d and 4e having 4c and an exhaust port 4f provided on the side portion of the chamber body 4a. This vacuum chamber 4 is mounted on a stand (not shown) or adjacent It is supported by being connected to another chamber or the like.

The magnet array 3 formed by a plurality of permanent magnets 2 has a fitting groove 5a extending in the axial direction of the vacuum chamber 4.
It is supported by a holder 5 having.

The permanent magnets 2 are fitted in the fitting groove 5a such that the permanent magnets 2 whose N poles are exposed to the outside and the permanent magnets 2 whose S poles are exposed to the outside are adjacent to each other. The two retainers 6 and 6 that are in contact with the left and right edges of the surface exposed from the holder 5 and are fixed to the holder 5 are restrained by the holder 5.

Further, moving mechanisms 7U and 7L for moving the magnet rows 3 and 3 toward and away from each other are provided on the upper and lower portions of the vacuum chamber 4.

The upper moving mechanism 7U is a chamber body 4a.
A plurality of rods 8U penetrating the top of the chamber so as to move up and down toward the inside of the chamber body 4a, and an internal lifting beam 9U that is disposed inside the chamber body 4a and has its upper surface fixed to the lower end of the rod 8U. A supporting member 10U which is arranged above the chamber body 4a and whose lower surface is fixed to the upper end of the rod 8U, and a supporting member 10U which is arranged above the supporting member 10U and whose lower surface is positioned via the position adjusting member 11U. External lifting beam 12U connected to the upper surface of member 10U
And a piston rod 13 arranged above the external lifting beam 12U and extending toward the axis of the chamber body 4a.
The tip of a is composed of a fluid pressure cylinder (actuator) 13U fixed to the upper surface of the external lifting beam 12U, and the cylinder body 13b of the fluid pressure cylinder 13U is supported by a fixed structure 14 such as a pedestal. Has been done.

Furthermore, inside the chamber body 4a, the outer peripheral surface of the portion of each rod 8U located inside the chamber body 4a is circumferentially covered, and the upper and lower ends are the inner peripheral surface of the chamber body 4a. A bellows 15U, which is airtightly mounted on the upper surface of the lifting beam 9U, is provided, and the chamber body 4 of each rod 8U is provided outside the chamber body 4a.
A bellows 16U is provided, which covers the outer peripheral surface of the portion located outside of a in the circumferential direction and is hermetically attached to the top of the outer peripheral surface of the chamber body 4a and the lower surface of the support member 10U at the lower and upper ends.

The lower moving mechanism 7L is a chamber main body 4a.
A plurality of rods 8L penetrating through the bottom part of the chamber body 4a so as to be able to move up and down, and an interior arranged inside the chamber body 4a so as to be positioned below the internal lifting beam 9U of the upper moving mechanism 7U. Lifting beam 9L, support member 10L arranged below chamber body 4a, position adjusting member 11L, external lifting beam 12L, fluid pressure cylinder 1
3L and bellows 15L for covering the rod 8L,
16L, the tip end of the piston rod 13a of the fluid pressure cylinder 13L is fixed to the lower surface of the external lifting beam 12L, and the cylinder body 13b of the fluid pressure cylinder 13L is provided.
Is supported by the fixed structure 14, the upper moving mechanism 7U described above is vertically inverted about the axis of the chamber body 4a.

The holders 5 and 5 for supporting the pair of magnet rows 3 and 3 have internal lifting beams 9U of the upper moving mechanism 7U and internal lifting beams 9L of the lower moving mechanism 7L described above.
The permanent magnets 2 having different polarities are attached so as to face each other.

Each member forming the vacuum chamber 4, the holder 5 supporting the magnet array 3, and each member forming both moving mechanisms 7U, 7L are made of a non-magnetized material such as SUS316L (stainless steel). In the inside of 4, a magnetic field m ₁ that vertically extends from the lower side thereof and a magnetic field m ₂ that horizontally extends from the upper side to the lower side thereof are alternately generated in the traveling direction of the electron beam e.

When the emitted light X (see FIG. 7) is generated by the insertion light source shown in FIGS. 4 to 6, the vacuum chamber 4 is used.
The inside of an electron storage ring or a linear accelerator, etc., in which is installed is depressurized to a high vacuum state, and then an electron beam e is directed toward the inside of the vacuum chamber 4 by an electron generator or the like.
When the electron beam e is emitted,
₁ and m ₂ receives the Lorentz force to meander in the vacuum chamber 4 while meandering left and right, and as a result, the radiated light is tangential to the trajectory of the electron beam e at the position where the trajectory of the electron beam e bends. X is generated.

When the wavelength of the emitted light X or the like is changed according to the purpose of use of the emitted light X, fluid pressure is applied to the fluid pressure cylinder 13U of the upper moving mechanism 7U, and the external elevating beam 12U, position. By lowering or raising the holder 5 supporting one magnet row 3 via the adjusting member 11U, the supporting member 10U, the rod 8U, and the internal elevating beam 9U, the one magnet row 3 is aligned with the axis of the chamber body 4a. Move or move away from each other.

At the same time, a fluid pressure is applied to the fluid pressure cylinder 13L of the lower moving mechanism 7L via the external lifting beam 12L, the position adjusting member 11L, the support member 10L, the rod 8L, and the internal lifting beam 9L. The other magnet row 3
By raising or lowering the holder 5 supporting the magnet, the other magnet array 3 is moved toward or away from the axis of the chamber body 4a.

As a result, the pair of magnet arrays 3 and 3 come close to or away from each other, and the strengths of the magnetic fields m ₁ and m ₂ acting on the electron beam e traveling inside the vacuum chamber 4 change.

[0024]

However, since the permanent magnets 2 constituting the magnet array 3 are porous materials when viewed microscopically as a fired product obtained by firing and solidifying powdery granular ceramics, As shown in FIGS. 4 to 6, in the insertion light source in which the magnet rows 3 and 3 are housed inside the vacuum chamber 4 incorporated in the electron storage ring or the linear accelerator, the inside of the electron storage ring or the linear accelerator is Even if the pressure is once reduced to a high vacuum state, gas such as air is gradually released from the permanent magnet 2 which is a porous body.

When gas is released from the permanent magnet 2 in this manner, an electron storage ring including the vacuum chamber 4
Alternatively, it becomes difficult to maintain the inside of the linear accelerator or the like in a high vacuum state that is optimal for the electron beam e to travel, and the radiated light X (see FIG. 7) cannot be efficiently generated.

The present invention has been made in view of the above situation, and an object thereof is to provide an insertion light source capable of suppressing the emission of gas from a magnet.

[0027]

In order to achieve the above object, the present invention provides a vacuum chamber through which an electron beam passes,
The vacuum chamber is provided with a pair of magnet rows composed of a plurality of magnets of the same shape that are opposed to each other so as to sandwich the electron beam passage position, and magnets having different polarities face each other across the electron beam passage position. In addition, a magnetic field directed from one side of the vacuum chamber to the other side orthogonal to the traveling direction of the electron beam and a magnetic field directed from the other side of the vacuum chamber to the other side orthogonal to the traveling direction of the electron beam. In the insertion light source in which the magnets forming the magnet rows are arranged so as to be alternately formed in the traveling direction of the electron beam, the exposed surface of each magnet row is hermetically covered with a sealing member made of a thin plate material that is not magnetized. are doing.

[0028]

In the insertion light source of the present invention, the exposed surface of the magnets forming the magnet array arranged inside the vacuum chamber is airtightly covered by the sealing member made of a thin plate material that is not magnetized, and the inside of the vacuum chamber is covered. It suppresses the release of gas from the magnet when the pressure is reduced.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of the insertion light source of the present invention. The basic structure of the magnet array 3, the vacuum chamber 4, the holder 5, the moving mechanisms 7U, 7L, etc. in this embodiment is as follows. This is the same as the above-mentioned conventional example (see FIGS. 4 to 6), and in the figure, the parts denoted by the same reference numerals as those in FIGS. 4 to 6 represent the same things.

In this embodiment, the portion of the magnet array 3 composed of a plurality of permanent magnets 2 exposed from the holder 5, that is, one end of the magnet array 3 (the end on the upstream side in the traveling direction of the electron beam e). ) And the other end (the end on the downstream side in the traveling direction of the electron beam e) and a portion facing the other magnet row 3 are integrally provided with a seal member 17, and the outer edge portion of the seal member 17 is provided with an electron beam. The holder 5 is airtightly fixed by means such as welding.

This seal member 17 is made of SUS316L.
It is made of a thin plate material such as (stainless steel) that is not magnetized.

When the emitted light X (see FIG. 7) is generated by the insertion light source shown in FIGS. 1 to 3, the vacuum chamber 4
The inside of an electron storage ring or a linear accelerator, etc., in which is installed is depressurized to a high vacuum state, and then an electron beam e is directed toward the inside of the vacuum chamber 4 by an electron generator or the like.
When the electron beam e is emitted, the electron beam e undergoes Lorentz force due to the influence of the magnetic fields m ₁ and m ₂ and travels inside the vacuum chamber 1 while meandering left and right, and as a result, the orbit of the electron beam e bends. At X, radiation light X is generated in the tangential direction of the trajectory of the electron beam e.

When changing the wavelength of the emitted light X or the like according to the purpose of use of the emitted light X, the conventional example described above (see FIG. 4) is used.
From FIG. 6), the fluid pressure cylinders 13U, 13
By operating L, the pair of magnets 3 and 3 are moved toward or away from each other, and the strengths of the magnetic fields m ₁ and m ₂ acting on the electron beam e traveling inside the vacuum chamber 4 are adjusted.

At this time, in this embodiment, the magnet array 3
Since one end portion and the other end portion of the magnet and a portion facing the other magnet row 3 are covered with the seal member 17, the inside of the electron storage ring in which the vacuum chamber 4 is incorporated, or the linear accelerator is in a high vacuum state. Even if the pressure is reduced to 1, the gas such as air is not released from the permanent magnets 2 forming the magnet rows 3 and 3.

Therefore, it is possible to keep the inside of the electron storage ring including the vacuum chamber 4 or the linear accelerator in an optimum state for the electron beam e to travel, and the radiated light X (see FIG. 7). Can be efficiently generated.

The insertion light source of the present invention is not limited to the above-mentioned embodiment, and the seal member is made of a non-magnetizable material other than stainless steel such as aluminum alloy, and the other aspects of the present invention. It goes without saying that various changes can be made without departing from the scope of the invention.

[0038]

As described above, according to the insertion light source of the present invention, the exposed portion of the magnets forming the magnet array is covered with the sealing member made of a thin plate material that is not magnetized, so that the vacuum chamber is provided. Even if the pressure is reduced to a high vacuum state, no gas is released from the magnet, and it becomes possible to keep the inside of the vacuum chamber in an optimal state for the electron beam to travel.
The excellent effect that radiated light can be efficiently generated can be exhibited.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an insertion light source of the present invention.

FIG. 2 is a vertical sectional view showing an embodiment of the insertion light source of the present invention.

FIG. 3 is a cross-sectional view showing details of the permanent magnet, the holder, and the seal member shown in FIG.

FIG. 4 is a cross-sectional view showing an example of a conventional insertion light source.

FIG. 5 is a vertical sectional view showing an example of a conventional insertion light source.

6 is a transverse cross-sectional view showing details of a permanent magnet and a holder shown in FIG.

FIG. 7 is a partially cutaway perspective view showing the principle of the insertion light source.

[Explanation of symbols]

2 magnets 3 magnet array 4 vacuum chamber 17 sealing member e electron beam m ₁ magnetic field m ₂ magnetic field

Claims (1)

[Claims] 1. A vacuum chamber through which an electron beam passes,
The vacuum chamber is provided with a pair of magnet rows composed of a plurality of magnets of the same shape that are opposed to each other so as to sandwich the electron beam passage position, and magnets having different polarities face each other across the electron beam passage position. In addition, a magnetic field directed from one side of the vacuum chamber to the other side orthogonal to the traveling direction of the electron beam and a magnetic field directed from the other side of the vacuum chamber to the other side orthogonal to the traveling direction of the electron beam. In the insertion light source in which the magnets forming the magnet rows are arranged so as to be alternately formed in the traveling direction of the electron beam, the exposed surface of each magnet row is hermetically covered with a sealing member made of a thin plate material that is not magnetized. An insertion light source characterized by the above.