JPH06275399A - Undulator - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object to provide an undulator capable of changing the wavelength of emitted light to be extracted. [Structure] An undulator 5 for extracting emitted light by deflecting an electron beam with a periodic magnetic field. In this undulator 5, an upper magnet group 6 and a lower magnet group 7 are arranged separately along a horizontally arranged orbit 2 through which an electron beam passes at a speed close to the speed of light. The upper and lower magnet groups 6 and 7 include a supporting portion 9 horizontally arranged as a constituent member thereof.
As a result, only horizontal movement is permitted and the plurality of magnet units 10 ...
Is provided. The position adjustment mechanism 8 automatically sets the horizontal position of each of the plurality of magnet units 10 ... As an example of the position adjusting mechanism 8, a moving block 14 that moves in and out between the magnet parts 10 and 10,
There is a moving device 15 that simultaneously moves these moving blocks 14 ...

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an undulator for extracting emitted light (SOR light) by deflecting an electron beam with a periodic magnetic field, and more particularly to an undulator capable of varying the wavelength of the emitted light.

[0002]

2. Description of the Related Art FIG. 5 shows a basic structure of an undulator 1. Reference numeral 2 in the figure is the trajectory of the electron beam, and the electron beam having a velocity close to the speed of light passes along the trajectory 2. In addition, magnets 3 and 3 having opposite polarities are arranged to face each other above and below the track 2. Then, these magnets 3 and 3 have the orbit 2
Are arranged side by side along the longitudinal direction, and their polarities change periodically, that is, magnets 3 ... Adjacent to the longitudinal direction are arranged so as to have mutually opposite polarities.

Therefore, a vertical magnetic flux is generated between a predetermined pair of upper and lower magnets 3, 3, and a reverse magnetic field is generated between the pair of upper and lower magnets 3, 3 adjacent to the upper and lower magnets 3, 3. Since a magnetic flux in the vertical direction is generated, a periodic magnetic field is given to the electron beam passing through the orbit 2, and the electron beam meanders in the direction perpendicular to the magnetic flux, that is, in the horizontal direction, and is divided by an integer fraction of the period length λμ of the magnet. The emitted light with a wavelength is extracted. The emitted light extracted from the undulator 1 is used for a free electron laser device (not shown) or the like.

[0004]

By the way, there are cases where it is desired to change the wavelength of the emitted light appropriately in a free electron laser device or the like which utilizes the emitted light extracted from the undulator 1. However, in the conventional undulator 1 shown in FIG. 1, only radiant light having a predetermined wavelength can be extracted, and development of an undulator in which the wavelength of the radiated light is variable has been desired.

In view of the above circumstances, it is an object of the present invention to provide an undulator capable of changing the wavelength of emitted light to be extracted.

[0006]

An undulator according to claim 1 of the present invention is an undulator for extracting emitted light by deflecting an electron beam with a periodic magnetic field,
A horizontally arranged orbit through which the electron beam passes at a speed close to the speed of light, an upper magnet group and a lower magnet group which are arranged above and below the orbit at a distance from each other, and which are arranged to face each other,
The upper and lower magnets are configured to automatically set the horizontal positions of the magnets and the magnets that are allowed to move horizontally only in the longitudinal direction of the track due to the horizontally arranged support. It is characterized by having a position adjusting mechanism.

An undulator according to claim 2 is
2. The position adjusting mechanism according to claim 1, wherein adjacent magnet portions are separated from each other when entering between a plurality of magnet portions, and are adjacent to each other by retreating from between the magnet portions. The present invention is characterized in that a plurality of moving blocks that bring the magnet parts closer to each other and a moving device that moves the plurality of moving blocks forward and backward at the same time are provided.

The undulator according to claim 3 is
2. The position adjusting mechanism according to claim 1, wherein a predetermined magnet portion of the upper magnet group and a predetermined magnet portion of the lower magnet group are connected by a link member and arranged in the upper and lower magnet groups. The present invention is characterized in that a link mechanism formed by hinge-connecting a plurality of linked link members is used.

[0009]

According to the undulator of the present invention, the plurality of magnet portions constituting the upper magnet group and the lower magnet group are horizontally moved by the position adjusting mechanism so that the adjacent magnet portions are separated from each other by a predetermined distance. As a result, a long periodic magnetic field is given to the electron beam passing through the orbit. Thereby, the emitted light with a long wavelength is extracted.

When all the magnet parts of the upper magnet part and the lower magnet part are horizontally moved by the position adjusting mechanism so that the adjacent magnet parts come close to each other, the electron beam passing through the orbit is moved. A short periodic magnetic field is applied.
Thereby, the emitted light with a short wavelength is extracted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the undulator of the present invention will be described below with reference to FIGS. The same components as those shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

1 to 3 show an undulator 5 of a first embodiment, in which an upper magnet group 6 and a lower magnet group 7 are arranged above and below a predetermined distance from a track 2. At the same time, these magnet groups are
The movement control is performed by. And
The upper magnet group 6 and the lower magnet group 7 include a plurality of magnet parts 10 ...
Are arranged in rows while being supported by the support rods 9 arranged in the horizontal direction. The magnet portions 10 and 10 that are vertically opposed to each other with the track 2 in between have polarities opposite to each other. The horizontally adjacent magnet parts 10 are arranged so as to have polarities opposite to each other.

FIG. 3A is a front view of the magnet portion 10, FIG.
FIG. 3B is a side view of the magnet unit 10. This magnet part 10
Is a rectangular parallelepiped holder 11 in which a permanent magnet 12 is incorporated. Then, each holder 11 is a member of the same shape in which the surfaces of the other adjacent magnet portions 10 facing the holders 11 are inclined surfaces 11a so as to be separated from the lower portion toward the upper portion. In addition, two through holes 11 are provided in the horizontal direction orthogonal to the inclined surface 11 a of each holder 11.
b and 11b are provided.

The above-mentioned support rods 9 and 9 penetrate through the through holes 11b and 11b of the holders 11, and only the central magnet portion 10a is fixed to the support rods 9 and 9 and other magnets. The portions 10 ... Are supported by the support rods 9, 9 in a state in which horizontal movement is permitted.

Further, the position adjusting mechanism 8 includes the magnet portions 10 ...
An up-and-down moving part 13 arranged in parallel with the track 2 at an upper part or a lower part, and a moving block 14 connected to the lower surface or the upper surface of the up-and-down moving part 13 by allowing only horizontal movement, A plurality of moving devices 15 for moving the parts in the vertical direction, and the magnet parts 10b, 10c at the left and right ends of the lower magnet group 6 and the upper magnet group 7, respectively.
Pressing device 16 for pressing toward 0a and each moving device 15
And an arithmetic unit 17 which sends a drive signal to the.

The moving blocks 14, which are allowed to move only in the horizontal direction by the vertical moving part 13, are inserted between the magnet parts 10 and the inclined surfaces 1 of the adjacent magnet parts 10, 10.
All of the members have the same shape and are formed in a truncated pyramid shape in a side view having an inclined surface 14a so as to come into contact with 1a.

The moving device 15 employs, for example, a hydraulic device in which an arm expands and contracts in the vertical direction. When a drive signal is sent, the upper or lower three moving devices 1 are used.
The arms 5 are simultaneously expanded and contracted at the same distance to move the moving blocks 14 ...

The pressing device 16 employs, for example, a hydraulic mechanism in which the arm expands and contracts in the horizontal direction. The pressing device 16 arranged on the left side in the figure has an arm on the holder 11 of the leftmost magnet portion 10b. Touches and applies a constant pressing force to the right side, and the pressing device 16 disposed on the right side applies a pressing force to the left side by the arm contacting the holder 11 of the magnet portion 10c disposed on the rightmost side. It is designed to be used. The left and right pressing devices 16, 16 are set to have the same pressing force.

Further, the arithmetic unit 17 includes a moving unit 15 ...
A drive signal is sent so that the arms are operated at the same distance with respect to.

Next, the operation of extracting the emitted light by the undulator 5 having the above structure will be described. First, in order to take out radiated light having a short wavelength, as shown in FIG. 1, the arms of the upper and lower moving devices 15 ... Are retracted by a predetermined distance in response to a drive signal from the computing device 17. As a result, the moving blocks 14 ... When the moving block 14 moves backward,
The magnet parts 10 ... Which are pressed toward the central part in the horizontal direction by the upper and lower pressing devices 16 move horizontally toward the central magnet part 10a. Then, the inclined surfaces 11a of the respective magnet portions 10 ... Abut on the inclined surfaces 14a of the moving block 14 which is arranged between them and retreated, and stops. As a result, the distance between the adjacent magnets 10 and 10 is set to L1 and the magnet portions 10 are arranged.

When the electron beam is allowed to pass through the track 2 in this state, a vertical magnetic flux is generated between the magnet portions 10 and 10 facing each other in the vertical direction, and a horizontal magnetic flux adjacent to the pair of magnets 10 and 10 in the vertical direction is generated. Magnetic flux in the opposite vertical direction is generated between the pair of magnets 10 and 10, but a short periodic magnetic field is given to the electron beam passing through the orbit 2. Then, radiated light having a short wavelength is extracted from the undulator 5.

On the other hand, in order to take out radiation having a long wavelength,
As shown in FIG. 2, a drive signal from the arithmetic unit 17 causes the arms of the upper and lower moving units 15 ... To move forward by a predetermined distance. Thereby, together with the up-and-down moving parts 13 and 13,
The moving blocks 14 move forward by a predetermined distance. When the moving block 14 moves forward, the inclined surfaces 14a slide on the inclined surfaces 11a of the magnet portions 10 ...
0 ... is horizontally moved in the left-right direction away from the central magnet portion 10a. As a result, the distance between the adjacent magnets 10 and 10 is set to L2 (L2> L1), and the magnet portions 10 ...
Are placed.

When the electron beam passes through the trajectory 2 in this state, a long periodic magnetic field is given to the electron beam passing through the trajectory 2. Then, radiated light with a long wavelength is extracted from the undulator 5.

As can be easily understood from the above description, according to the undulator 5 of this embodiment, when the predetermined drive signal from the arithmetic unit 17 is obtained, the upper and lower pressing devices 15 ... The vertical moving parts 13, 13, the moving blocks 14, ...
Can be easily moved to a predetermined distance L1, L2,
As a result, a long and short periodic magnetic field is applied to the electron beam passing through the orbit 2, and radiation light having a predetermined wavelength can be extracted as appropriate.

Next, FIG. 4 shows an undulator 20 of another embodiment of the present invention. The same components as those shown in FIGS. 1 to 3 are designated by the same reference numerals and the description thereof will be omitted. In this example,
Similar to the undulator 5 in FIGS. 1 to 3, the upper magnet group 6
Also, the lower magnet group 7 is supported by the support rods 9 and 9 so that only horizontal movement is allowed, and a link mechanism 21 is arranged between the upper magnet group 6 and the lower magnet group 7. There is. Note that only the rightmost magnet portions 10g and 10g are restricted from moving in the horizontal direction.

In the link mechanism 21, for example, a predetermined magnet portion 10d on the upper side and a magnet portion 10f adjacent to the magnet portion 10e on the lower side facing the magnet portion 10d are interlocked with each other. A large number of link members 21 in the magnet portion 10 ...
a ... hinge-connected and each link member 21a, 21a
It is a mechanism in which the intersecting part of is also hinged. Also,
On the side of the leftmost magnet portions 10d and 10e, for example, a pressing device 16 for extending and contracting an arm is provided.
Then, a predetermined drive signal is sent from the arithmetic unit 17 to the pressing device 16.

According to the undulator 20 having the above structure,
The upper and lower pressing devices 1 are driven by a drive signal from the arithmetic unit 17.
When the arms 6 and 16 are extended to the same length, as the link member 21a of the link mechanism 21 moves, the magnet units 10 move to the right in the figure, and the distance between the adjacent magnets 10 and 10 increases. Is set to be short and each magnet unit 10
... is placed. As a result, when the electron beam passes through the orbit 2, a short periodic magnetic field is given to the electron beam passing through the orbit 2, and radiant light with a short wavelength is extracted from the undulator 20. Also, the upper and lower pressing devices 1
When the arms 6 and 16 are reduced, the magnet members 10 ... Move to the left side in the figure as the link member 21a of the link mechanism 21 moves, and the distance between the adjacent magnets 10 is set longer. Each magnet part 10 is arranged.
As a result, when the electron beam passes through the orbit 2, a long periodic magnetic field is given to the electron beam passing through the orbit 2, and radiant light with a long wavelength is extracted from the undulator 20. Therefore, the undulator 20 of the present embodiment
Can obtain the same effect as that shown in FIGS.

[0028]

As described above, in the undulator of the present invention, the plurality of magnet portions forming the upper magnet group and the lower magnet group are positioned so that the adjacent magnet portions are separated from each other by a predetermined distance. When moved horizontally by the adjusting mechanism, a long periodic magnetic field is given to the electron beam passing through the orbit, and radiated light with a long wavelength can be extracted, while adjacent magnets come close to each other. When all the magnet parts of the upper magnet part and the lower magnet part are horizontally moved by the position adjustment mechanism as described above, a short periodic magnetic field is given to the electron beam passing through the orbit, and synchrotron light with a short wavelength is extracted. be able to. Therefore, the present invention can provide an undulator capable of changing the wavelength of the emitted radiated light.

[Brief description of drawings]

FIG. 1 is a side view showing a state in which radiated light having a short wavelength is taken out in an undulator according to a first embodiment of the present invention.

FIG. 2 is a side view showing a state in which radiation light having a long wavelength is extracted in the undulator according to the second embodiment of the present invention.

FIG. 3 is a diagram showing a magnet unit according to the present invention.

FIG. 4 is a side view showing an undulator according to a second embodiment of the present invention.

FIG. 5 is a schematic view showing a conventional undulator.

[Explanation of symbols]

 2 orbits 5, 20 undulator 6 upper magnet group 7 lower magnet group 8 position adjusting mechanism 9 support rod (support portion) 10 magnet portion 11 holder 12 permanent magnet 13 vertical moving portion 14 moving block 15 moving device 16 pressing device 17 computing device 21 Link mechanism 21a Link member

Claims (3)

[Claims] 1. An undulator for extracting emitted light by deflecting an electron beam with a periodic magnetic field, the orbit being horizontally arranged through which the electron beam passes at a speed close to the speed of light, and upward and downward along the orbit. A plurality of upper magnet groups and a lower magnet group, which are spaced apart from each other and are opposed to each other, and a plurality of upper and lower magnet groups that are configured to be horizontal and are allowed to move only horizontally in the longitudinal direction of the track by the horizontally arranged support portions. An undulator comprising: a magnet unit; and a position adjusting mechanism that automatically sets the horizontal position of each of the plurality of magnet units. 2. The undulator according to claim 1, wherein the position adjusting mechanism separates adjacent magnets from each other when entering between the plurality of magnets, and retracts from between the magnets. An undulator comprising: a plurality of moving blocks that bring adjacent magnet parts closer to each other; and a moving device that simultaneously moves the plurality of moving blocks forward and backward. 3. The undulator according to claim 1, wherein in the position adjusting mechanism, a predetermined magnet portion of the upper magnet group and a predetermined magnet portion of the lower magnet group are connected by a link member, and the upper and lower portions are connected. An undulator comprising a link mechanism in which a plurality of link members arranged in a magnet group are hinge-connected to each other.