JP2000311799A - Insertion light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insertion light source capable of generating efficiently a radiation ray. SOLUTION: This light source is provided with a vacuum chamber 8 formed into an elliptic shape of cross-section, in an inside of which an electron beam propagates, and a pair of magnet lines 6, 6 arranged to sandwich the vacuum chamber 8. A wall of the vacuum chamber 8 is formed to have a thin wall thickness so as to reduce a space (b) between the magnet lines 6, 6 and to enlarge a space (a) inside the chamber 8, the magnet lines 6, 6 are brought into face-contact with an outside flat part of the vacuum chamber 8, and the chamber 8 is fixed to the magnet lines 6, 6 to keep flatness of a thin-walled vacuum chamber 8 inner face thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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 by a magnetic field or an electric field, an electromagnetic wave (light) called radiation is emitted in a tangential direction of an electron orbit.

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

FIG. 2 shows the principle of an insertion light source.
In this insertion light source, a magnet row main body composed of a plurality of permanent magnets 2 is provided on both sides of a substantially horizontally extending vacuum chamber 1 which is incorporated in an electron storage ring or a linear accelerator and in which an electron beam e travels. 3 are arranged.

The vacuum chamber 1 is made of a non-magnetized material such as an aluminum alloy.

The permanent magnets 2 constituting the magnet row main body 3 are opposed to each other by the permanent magnets 2 having different polarities across the vacuum chamber 1 and from one side of the vacuum chamber 1 to the other side with respect to the traveling direction of the electron beam e. A magnetic field m1 oriented orthogonally and a magnetic field m2 oriented orthogonally to the traveling direction of the electron beam e from the other side of the vacuum chamber 1 to one side are alternately generated.

FIG. 3 shows an example of a conventional insertion light source. In this insertion light source, a magnet row main body 3 composed of a plurality of permanent magnets 2 is arranged in parallel with a vacuum chamber 1 as described above. Two clamps 5 and 5
To form a magnet row 6.

The cross section of the vacuum chamber 1 is formed in an elliptical shape.

The holder 4 has a fitting groove 7 extending in a direction perpendicular to the paper surface of FIG.
The permanent magnet 2 whose south pole is exposed to the outside (the side where the magnet rows 6 and 6 are opposed in FIG. 3) and the permanent magnet 2 not shown in FIG. 3 where the north pole is exposed to the outside are adjacent to each other. Mated.

[0010] Of the corners of the permanent magnet 2 to be mounted on the holder 4, the corners extending in the axial direction of the vacuum chamber 1 and not adjacent to other permanent magnets 2 are chamfered by about 45 degrees. ing.

The permanent magnet 2 fitted in the fitting groove 7
The two clamps 5, 5 abutting on the chamfered corners exposed from the holder 4 of the permanent magnet 2 and fixed to the holder 4 and extending in the axial direction of the vacuum chamber 1. It is restrained by the holder 4.

Each of the holder 4 and the clamps 5, 5 is made of a non-magnetized material such as SUS316L (stainless steel).

When the emitted light X is generated by the insertion light source shown in FIG. 3, the inside of the electron storage ring, in which the vacuum chamber 1 is incorporated, or the linear accelerator, etc., is depressurized to a high vacuum state. For example, the electron beam e is emitted toward the inside of the vacuum chamber 1.

This electron beam e is generated by the magnetic field m described above.
Under the Lorentz force due to the influence of 1, m2 (see FIG. 2), the vacuum chamber 1 travels while meandering up and down inside the chamber 1,
As a result, at the place where the trajectory of the electron beam e bends, the radiation X (see FIG. 2) in the tangential direction of the trajectory of the electron beam e.
Occurs.

In such an insertion light source, the smaller the distance b between the two magnet row bodies 3 is, the stronger the magnetic force acting on the electron beam e is. As the distance a between the inner surfaces of the vacuum chamber 1 is larger, the loss due to the collision of the electron beam e with the inner surface of the vacuum chamber 1 is reduced, and the generation efficiency of the radiation X is improved.

[0016]

However, in the insertion light source shown in FIG. 3, for example, when the width w of the vacuum chamber 1 is about 150 mm, the wall thickness is set to 3.4.
If the distance is not set to 4 mm to 4 mm, deformation due to internal pressure reduction occurs in the vacuum chamber 1.

That is, in the conventional insertion light source, it is structurally difficult to reduce the wall thickness of the vacuum chamber 1.
There is a limit in increasing the interval a of the inner surface of the vacuum chamber 1 with respect to the interval b of the magnet row bodies 3.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an insertion light source capable of efficiently generating radiated light.

[0019]

In order to achieve the above object, in the insertion light source of the present invention, there is provided a vacuum chamber having an oval cross section and an electron beam traveling inside, and a vacuum chamber sandwiching the vacuum chamber. With a pair of magnet rows arranged,
The wall thickness of the vacuum chamber is made thin, and a row of magnets is brought into surface contact with a flat outer surface of the vacuum chamber, and the vacuum chamber is fixed to each row of magnets.

In the insertion light source according to the present invention, the gap between the magnet rows is reduced and the gap between the inner surfaces of the vacuum chamber is increased by forming the wall thickness of the vacuum chamber thin.

Further, by fixing the vacuum chamber to each magnet row by surface contact, the deformation of the vacuum chamber having a small wall thickness is suppressed, and the flatness of the inner surface of the vacuum chamber is maintained.

[0022]

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

FIG. 1 shows an example of an embodiment of an insertion light source according to the present invention. In FIG. 1, the same reference numerals as those in FIGS. 2 and 3 denote the same components.

This insertion light source comprises a vacuum chamber 8 in which an electron beam e (see FIG. 2) travels, and a vacuum chamber 8
A pair of magnet rows 6, 6 arranged so as to sandwich
And

The vacuum chamber 8 is formed of a non-magnetized material such as an aluminum alloy into a cylindrical body having a flat cross section and an oblong shape with a wall thickness of about 1.1 mm to 1.5 mm. Vacuum chamber 8 on both edges of flat part
Fixing members 9, 9 extending along the longitudinal direction are fixed.

The mounting member 9 has a thin portion fixed so as to be in surface contact with a flat portion on the outer surface of the vacuum chamber 8, and a thick portion connected to the thin portion and bolted to the side surface of the holder 4 of the magnet array 6. And is made of a non-magnetized material such as an aluminum alloy, like the vacuum chamber 8.

The holder 4 is formed with a notch 10 into which the thin portion of the mounting member 9 fits, and the mounting member 9 is fitted into the notch 10 so that the permanent magnet 2
The flat surface of the outer surface of the vacuum chamber 8 is in surface contact with the clamp 5.

As described above, in the insertion light source shown in FIG. 1, since the wall thickness of the vacuum chamber 8 is formed thin,
The distance b between the magnet rows 6 and 6 can be reduced and the distance a between the inner surfaces of the vacuum chamber 8 can be increased. Further, the vacuum chamber 8 is fixed to the holders 4 and 4 of the magnet rows 6 and 6 so as to make surface contact. Therefore, the flatness of the inner surface of the vacuum chamber 8 having a small wall thickness can be maintained.

Therefore, the magnetic fields of the magnet arrays 6, 6 effectively act on the electron beam e traveling inside the vacuum chamber 1,
Further, the loss due to the collision of the electron beam e with the inner surface of the vacuum chamber 1 is reduced, and the emitted light X can be generated efficiently.

It should be noted that the insertion light source of the present invention is not limited to only the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

[0031]

As described above, according to the insertion light source of the present invention, the wall thickness of the vacuum chamber is formed thin, and the interval between the magnet rows is reduced and the interval between the vacuum chambers is increased.
The magnetic field of the magnet row effectively acts on the electron beam inside the vacuum chamber, and the vacuum chamber is fixed to each magnet row so as to make surface contact, maintaining the flatness of the inner surface of the vacuum chamber. An excellent effect that the loss due to the collision of the electron beam with the inner surface is reduced, and thus the emitted light can be efficiently generated.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram illustrating the principle of an insertion light source.

FIG. 3 is a cross-sectional view showing an example of a conventional insertion light source.

[Explanation of symbols]

 6 Magnet row 8 Vacuum chamber

Claims (1)

[Claims] 1. A vacuum chamber having a cross section formed in an elliptical shape and through which an electron beam travels, and a pair of magnet rows arranged with the vacuum chamber interposed therebetween, so that the wall thickness of the vacuum chamber is reduced. An insertion light source, wherein a row of magnets is brought into surface contact with a flat portion of the outer surface of the vacuum chamber, and the vacuum chamber is fixed to each row of magnets.