JPH0992497A - Magnetic circuit for inserted light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide magnetic field strength greater than conventional ones. SOLUTION: Hybrid lines 20A, 20B of magnets, each comprising a plurality of permanent magnets and magnetic substances, are provided opposite to each other with a vacuum duct 40 between them. Magnetic substances 43A, 43B, 44A, 44B are provided on the interior wall side of the vacuum duct 40 which corresponds to the positions of the magnetic substances of each hybrid line of magnets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic circuit used in an insertion light source device for generating emitted light by meandering electrons having a velocity close to the speed of light. More specifically, it relates to a magnetic circuit for an insertion light source device in which the wavelength tuning range of emitted light is large.

[0002]

2. Description of the Related Art It is known that when an electron having a velocity close to the speed of light orbiting in an accelerator is caused to make a meandering motion by the bipolar magnetic field, radiated light is generated from each meandering point. Using this principle, strong synchrotron radiation (from infrared rays to X-rays) is generated when electrons moving at a speed close to the speed of light meander through a magnetic circuit that generates a sinusoidal periodic magnetic field using a permanent magnet or electromagnet. A device for generating (specific light of) is an insertion light source device (undulator).

The insertion light source device is constructed by arranging two magnet rows in which a plurality of permanent magnets are arranged so as to face each other so as to form a gap. This magnetic circuit is inserted into the linear portion of the electron storage ring so as to sandwich the vacuum chamber, and a sinusoidal periodic magnetic field is generated in the air gap of the magnetic circuit. The magnetic circuit for the insertion light source device uses a hull back (H
There are two types, a hybrid type in which a permanent magnet and a magnetic body (pole piece) are combined.

FIG. 3 shows an example of a conventional magnetic circuit for a hullback type insertion light source device. In this device, the magnet array 10A
And 10B are arranged in parallel in the vertical direction with a gap G therebetween, and a plurality of rectangular permanent magnets having different magnetization directions are arranged in each magnet row. For example, looking at one period composed of four permanent magnets, in the magnet array 10A, the permanent magnets 11A, 12A, 13A, and 14A whose magnetization directions are −y, −z, + y, and + z, respectively, have a gap G. Are arranged adjacent to each other in the axial direction to form one cycle, and in the magnet array 10B, the magnetization directions are −y, + z, + y, and −z, respectively.
The permanent magnets 11B, 12B, 13B, and 14B are arranged adjacent to each other in the axial direction of the gap G to form one cycle. Such an array is N (N is an integer of 2 or more).
The magnetic circuits are arranged by repeating the cycle. In the magnetic circuit configured as described above, a magnetic flux flow as indicated by a closed arrow occurs, and a periodic magnetic field is generated in the gap G.

The insertion light source device is used in various fields such as physics and chemistry to analyze a microstructure of a substance, a process of a chemical reaction, and the like, and more knowledge can be obtained by scanning by changing the wavelength of emitted light. can get. In particular, by using synchrotron radiation having a short wavelength and a high intensity, a finer structure can be analyzed.

The wavelength of the emitted light generated by the insertion light source device depends on the cycle length of the magnet or the magnetic field strength, but generally the magnetic field strength is changed to change the wavelength of the emitted light. The magnetic field strength is changed by changing the gap between the magnet rows. That is, the smaller the gap, the stronger the magnetic field.

[0007]

As described above, in the insertion light source device, conventionally, the wavelength of the emitted light is changed by changing the magnetic field strength by changing the gap. But,
Since the minimum width of the gap is limited by the device configuration,
There is a certain limit in obtaining a wide wavelength tuning range. That is, since the vacuum duct is inserted in the gap, the minimum width of the gap is limited by the outer (diameter) dimension of the vacuum duct, and is generally about 20 mm. Therefore, the upper limit of the magnetic field strength is limited due to the limitation of the device configuration, and the maximum wavelength of the emitted light obtained is also limited. That is, the tuning range of the wavelength of the emitted light is also narrowed.

[0008] Therefore, an object of the present invention is to provide a magnetic circuit for an insertion light source device which can obtain a magnetic field strength higher than that of the conventional one.

[0009]

According to a first aspect of the present invention, first and second hybrid magnet rows in which a plurality of permanent magnets and magnetic bodies are alternately arranged are opposed to each other via a vacuum duct. A magnetic circuit for an insertion light source device is provided, in which a magnetic body is provided on the inner wall side of the vacuum duct corresponding to the position of each magnetic body of each hybrid magnet array.

According to a second aspect of the present invention, a plurality of permanent magnets are arranged in proximity to the respective surfaces of the first and second hybrid magnet rows opposite to the vacuum duct.
The magnetic circuit for an insertion light source device according to claim 1, further comprising: a second permanent magnet array and a second permanent magnet array, respectively.

In the invention according to claim 1 of the present application, since the magnetic body is provided on the inner wall side of the vacuum duct corresponding to the position of each magnetic body of each hybrid magnet array, the gap of the magnetic circuit is substantially narrowed. , The strength of the magnetic field generated in the gap increases.

According to the second aspect of the present invention, a plurality of permanent magnets are arranged in proximity to the respective surfaces of the first and second hybrid magnet rows opposite to the vacuum duct. The magnetic field strength can be further increased by providing each of the second permanent magnet rows.

[0013]

Next, the present invention will be described more specifically with reference to embodiments.

FIG. 1 is a partial side sectional view showing an embodiment of a magnetic circuit for an insertion light source device of the present invention, and FIG. 2 is a partial front sectional view thereof. In this magnetic circuit, a hybrid magnet array 20A in which a plurality of permanent magnets and magnetic bodies are alternately arranged
And 20B are provided so as to face each other via the vacuum duct 40.

The hybrid magnet arrays 20A and 20B are
For example, looking at one cycle consisting of four constituent elements, in the magnet array 20A, from the magnetic body 23A, the permanent magnet 21A magnetized in the −z direction, the magnetic body 24A and the permanent magnet 22A magnetized in the + z direction. The magnet array 20B includes a magnetic body 23B, a permanent magnet 21B magnetized in the + z direction, a magnetic body 24B, and a permanent magnet 22B magnetized in the −z direction.

Further, on the inner wall of the vacuum duct 40, the magnetic bodies 23A, 24A of the hybrid magnet rows 20A and 20B,
Magnetic bodies 43A, 44A, 43B, 44B are arranged at positions facing 23B, 24B via the walls of the vacuum duct 40, respectively. These magnetic materials are provided so as to have a gap that does not hinder the progress of the electron beam.

In the magnetic circuit having the above structure, the magnetic field strength generated in the vacuum duct 40 is substantially equal to the vacuum duct 40.
Magnetic bodies 43A and 43B (or 44A and 4) disposed inside
4B) is inversely proportional to the gap. This gap can be set narrower than the conventional magnetic circuit, so the vacuum duct 4
The magnetic field intensity within 0 can be increased, and radiated light with a long wavelength can be obtained.

FIG. 3 is a partial side sectional view showing another embodiment of the magnetic circuit for an insertion light source device of the present invention, and FIG. 4 is a partial front sectional view thereof. In this device, hybrid magnet rows 20A and 20B in which a plurality of permanent magnets and magnetic bodies are alternately arranged are provided to face each other via a vacuum duct 40, and further, the hybrid magnet row 20A is provided on the inner wall of the vacuum duct 40.
The magnetic bodies 43A, 44A, 23B, and 24B of 20 and 20B are the same as those of the first embodiment in that the magnetic bodies 43A, 44A, 43B, and 44B are arranged at positions facing each other via the wall of the vacuum duct 40. .

In this embodiment, the hybrid magnet array 20 is used.
A row of permanent magnets 30 in which a plurality of permanent magnets are arranged close to the respective surfaces of A and 20B opposite to the vacuum duct.
A and 30B are provided respectively. Permanent magnet row 3
0A (30B) is formed by alternately arranging a plurality of 31A and 32A (31B and 32B) magnetized in the −y direction and the + y direction, respectively.

In the magnetic circuit having the above structure, the magnetic bodies 43A, 43B, 44A arranged in the vacuum duct 40,
In addition to the effect of 44B, permanent magnet rows 30A and 30B
This further improves the magnetic field strength.

[0021]

As described above, according to the present invention, it is possible to increase the magnetic field strength and obtain radiated light having a longer wavelength than before.

[Brief description of drawings]

FIG. 1 is a partial side sectional view showing an embodiment of a magnetic circuit for an insertion light source device of the present invention.

FIG. 2 is a partial front sectional view showing an embodiment of a magnetic circuit for an insertion light source device of the present invention.

FIG. 3 is a partial side sectional view showing another embodiment of the magnetic circuit for an insertion light source device of the present invention.

FIG. 4 is a partial front sectional view showing another embodiment of the magnetic circuit for an insertion light source device of the present invention.

FIG. 5 is a partial perspective view showing an example of a conventional magnetic circuit for a hullback type insertion light source device.

FIG. 6 is a partial cross-sectional view showing an example of a conventional magnetic circuit for a hullback type insertion light source device.

[Explanation of symbols]

 20A, 20B Hybrid magnet row 21A, 21B, 22A, 22B Permanent magnet 23A, 23B, 24A, 24B Magnetic body 30A, 30B Permanent magnet row 31A, 31B, 32A, 32B Permanent magnet 40 Vacuum duct 43A, 43B, 44A, 44B Magnetic body

Claims (2)

[Claims] 1. A first and a second hybrid magnet row, in which a plurality of permanent magnets and magnetic bodies are alternately arranged, are provided facing each other through a vacuum duct, and each magnetic body of each hybrid magnet row. A magnetic circuit for an inserted light source device, wherein a magnetic body is provided on the inner wall side of the vacuum duct corresponding to the position of. 2. A first and a second permanent magnet row in which a plurality of permanent magnets are arranged are provided in proximity to respective surfaces of the first and second hybrid magnet rows opposite to the vacuum duct. The magnetic circuit for an insertion light source device according to claim 1, wherein: