JPH03116700A - Synchrotron radiator - Google Patents

Abstract

PURPOSE:To intend a smaller size and a lower cost as a whole by shaping a total of deflecting electric magnet in a sector form, providing an iron core with the width of the yoke section set larger than the widths of the magnetic pole sections at a right angle to an electron orbit. CONSTITUTION:A total of deflecting electric magnet 31 is shaped in a sector form, using an iron core 33 with the width of the yoke section 37 set larger than the widths of the magnetic pole sections 35, 36 at a right angle to an electron orbit P. In this way, using an iron core favorable for reducing size which is supplied with magnetic field of about 1.5T, considered as maximum- effectiveness available field for iron core material, on the electron orbit P in the deflection section, the deflecting electric magnet 31 is made smaller while its deflection radius is made smaller. It is thus possible to intend a smaller-size and lower-cost radiator as a whole.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to synchrotron radiation, which can extract electromagnetic waves emitted when high-energy accelerated electrons are deflected by a magnetic field. Regarding equipment.

(Prior Art) As is well known, the degree of integration of a semiconductor device is greatly influenced by the exposure light source. Currently, ultraviolet light and the like are used as exposure light, but these lights are approaching their limits in terms of the degree of integration.

For this reason, research has recently been conducted on using highly directional electromagnetic waves (specifically, soft X-rays), which are emitted when high-energy accelerated electrons are deflected by a magnetic field, as exposure light. Several proposals have already been made for synchrotron radiation devices capable of transmitting this light.

FIG. 4 shows a schematic configuration of the proposed synchrotron radiation device. This device is equipped with a linear accelerator 1 that accelerates electrons to near the speed of light. The accelerated electrons are injected via a guide path and an injector 2 into a storage ring 3 under vacuum conditions.

The inside of the storage ring 3 is formed by a circulating cavity.

The storage ring 3 is not a perfect circular ring but is formed in the shape of a square frame. The four apexes are formed in an arc shape having a length of one-fourth of a circle with a predetermined radius of curvature. Deflecting electromagnets 4 are arranged near the four arcuate portions of the storage ring 3 to deflect electrons traveling within the storage ring 3 by 90° using a magnetic field. Each deflection electromagnet 4 includes an iron core 6 and a coil 7 wound around the iron core 6 and formed of a normal conducting coil or a superconducting coil. As shown in FIG. 5, the iron core 6 includes a pair of magnetic pole parts 8.9 that face each other in a direction orthogonal to the electron orbit plane with the electron orbit P in between, and these magnetic pole parts 8.9 are arranged around the central axis of the electron orbit P. It is provided with a yoke portion 10 that connects to the yoke portion 10, and is formed into a fan shape as a whole.

An electromagnet 11 is arranged near the straight part of the storage ring 4, and a high frequency acceleration cavity 12 is arranged at one place in the straight part.
is provided. A beam line 13 for guiding the generated synchrotron radiation to a predetermined location is connected to a portion of the wall of the arc-shaped portion of the storage ring 3 located outside the electron orbit P, and is connected in a tangential direction. connected in a relationship that extends to .

In this synchrotron radiation device, electrons accelerated by a linear accelerator 1 are made to enter a storage ring 3, and the electrons are deflected by a magnetic field given by a deflecting electromagnet 4 so as to follow an orbit, and are also subjected to high-frequency acceleration. It is accelerated to a higher energy in the cavity 12 and circulated. Then, synchrotron radiation emitted when the electrons are deflected by the magnetic field is extracted via the beam line 13.

However, even with the synchrotron radiation device configured as described above, there are the following problems. That is, in this device, as described above, it is necessary to attach the beam line 13 to the arc-shaped portion of the storage ring 3 in a relationship extending in the tangential direction thereof.

For this reason, the iron core 6 that constitutes a part of the deflection electromagnet 4
This inevitably results in the structure shown in FIG. 5, that is, the structure in which the yoke portion 10 is located inside the electron orbit P. As shown in FIG. 6, an iron core with such a structure can be classified from a manufacturing perspective by using a thin plate 21 punched out of a silicon steel plate or the like in the cross-sectional shape of the iron core, and a spacer 22 made of a thin magnetic plate placed on the outside of the deflection track.
There are two types: the so-called sector type, which is formed by stacking thin plates 21 radially with appropriate interposition, and the sector type, which is formed by stacking thin plates 21 with their positions shifted along the electron trajectory P, as shown in Fig. 7. There are those called cutangular shapes and those that are entirely formed by machining.

In order to make the synchrotron radiation device small and inexpensive,
It is desirable that the deflection electromagnet can be made smaller, that the magnetic field strength of the deflection electromagnet can be increased, that the deflection radius can be made smaller, that the deflection angle of one deflection electromagnet can be increased, and that the number of deflection electromagnets can be reduced. It will be done. When considered from this point of view, when the iron core is configured in a recutangular type, the outer diameter of the iron core is structurally larger than that in a sector type, and the upper limit of the deflection angle is about 45°. Therefore, it is preferable to adopt the sector type. However, in a conventional sector-type iron core, the width L2 of the magnetic pole part 8.9 in the direction orthogonal to the electron trajectory P and the width L1 of the yoke part 10 in the direction orthogonal to the electron trajectory P are usually approximately equal to each other. are equal. Therefore, the magnetic pole part 8
．． The cross-sectional area of the magnetic flux path of the yoke portion 10 is significantly smaller than the cross-sectional area of the magnetic flux path of the yoke portion 9. As a result, the maximum magnetic field on the electron orbit P is considered to be the most effectively utilized magnetic field of the iron core material.
, it was not possible to raise the temperature to about 5T, and the limit was about 1.2T. For this reason, there was a problem in that the characteristics of the sector type could not be maximized.

(Problems to be Solved by the Invention) As mentioned above, in the conventional synchrotron radiation device, if an attempt is made to downsize the deflection electromagnet and the overall size, it is not possible to supply a high magnetic field. There was a problem.

Therefore, the present invention makes it possible to supply a magnetic field as high as the maximum effective magnetic field of the core material even if a sector type, which is advantageous for downsizing, is used as the iron core of the deflecting electromagnet, thereby realizing overall downsizing and cost reduction. The purpose is to provide a synchrotron radiation device.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, in the synchrotron radiation device according to the present invention, as the iron core of the deflection electromagnet, a magnet that is perpendicular to the electron orbit plane across the electron orbit is used. It is equipped with a pair of magnetic pole parts facing each other in the direction and a yoke part that connects the above pair of magnetic pole parts around the central axis of the electron orbit. The width of the part in the direction orthogonal to the electron orbit is set to be large.

(Function) Since the widths of the magnetic pole portion and the yoke portion are set in the above relationship, the cross-sectional area of the magnetic flux path of the yoke portion can be made equal to or greater than that of the magnetic pole portion. Therefore, even with a sector-type core configuration, 1.5T
It becomes possible to supply a magnetic field of approximately

(Example) Examples will be described below with reference to the drawings.

FIG. 1 shows only one deflecting electromagnet 31 incorporated in a synchrotron device according to an embodiment of the present invention. The synchrotron radiation device according to the present invention is characterized by the configuration of the deflection electromagnet. Therefore, other parts are omitted here.

The deflection electromagnet 31 in this example has a function of deflecting electrons traveling in the storage ring 32 by 90 degrees,
It is composed of an iron core 33 and a coil 34, which is a normal conducting coil or a superconducting coil, wound around the iron core 33.

The iron core 33 is formed in a sector shape, and has a pair of magnetic pole parts 35 and 36 that face each other in a direction perpendicular to the electron orbit plane with the electron orbit P1, that is, the storage ring 32 in between, and these magnetic pole parts 35 and 36 are It is provided with a yoke portion 37 that connects around the central axis of the orbit P, and is formed into a fan shape as a whole. Then, as shown in FIG. 2, the magnetic pole part 35 (36)
From the width L2 in the direction perpendicular to the electron trajectory P, the yoke part 3
The width in the direction perpendicular to the electron orbit P of No. 7 is set to be large. That is, by setting the widths L2 and Ll in the above relationship, the cross-sectional area of the magnetic flux path of the yoke portion 37 is made to be equal to or greater than that of the magnetic pole portions 35 and 36.

In the synchrotron radiation device having the deflection electromagnet 31 configured in this way, the cross-sectional area of the magnetic flux path of the yoke portion 37 of the iron core 33 incorporated in the deflection electromagnet 31 is the same as that of the magnetic pole portion 35.
The setting is equal to or higher than that of 36, which works effectively to supply a magnetic field of about 5 T per tube, which is considered to be the maximum effective magnetic field of the iron core material, on the electron trajectory P in the deflection part. can do. That is, by using a sector-type core that is advantageous for miniaturization, the supplied magnetic field can be increased to about the upper limit determined by the core material. Therefore, the deflection radius can be reduced while the deflection electromagnet 31 is made smaller, and as a result, the entire radiation device can be made smaller and lower in price.

Note that the present invention is not limited to the embodiments described above. That is, as shown in FIG. 3, the sector type is slightly deformed to satisfy the condition Ll>L2 and to
Both end surfaces 38a and 38b of a in the electron orbit P direction are formed in a shape that intersects the electron orbit P at an angle θ of 90° or less on the electron orbit plane to further increase the magnetic flux path cross-sectional area of the yoke portion 37. You may also do so. Further, in each of the above-mentioned examples, the electron beam is deflected by 90 degrees by the deflecting electromagnet, but the present invention can deflect the electron beam by 60 degrees or by 1.
4 can be applied to any deflection angle such as 80° deflection.

Furthermore, when prioritizing miniaturization, it is also effective to increase the power source for exciting the coil in combination with the above-mentioned means and supply a magnetic field of 1.5 T or more.

[Effects of the Invention] As described above, according to the present invention, it is possible to particularly downsize and enhance the functionality of the deflecting electromagnet, thereby realizing downsizing and cost reduction of the entire device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing only one deflection electromagnet incorporated in a synchrotron radiation device according to an embodiment of the present invention, and FIG. 2 is a perspective view taken along line A-A in FIG. Figure 3 is a diagram showing a modified example of the iron core corresponding to Figure 2, Figure 4 is a schematic configuration diagram of a synchrotron radiation device, and Figure 5 is a diagram of a conventional synchrotron radiation device, as seen in the direction of the arrow. Perspective view of the iron core in the built-in deflection electromagnet, No. 6
FIG. 7 and FIG. 7 are diagrams for explaining the conventional iron core shape, respectively. 1...Linear accelerator, 3...Storage ring, 12...
High frequency acceleration cavity, 13...beam line, 31...
Deflection electromagnet, 32...Storage ring, 33.33a.
...Iron core, 34...Coil, 35.36...Magnetic pole part, 37...Yoke part, 38a, 38b...End face, P
...electron orbit.

Claims (2)

[Claims] (1) High-energy electrons are made to enter a storage ring maintained in a vacuum state, and the incident electrons are deflected by a plurality of deflecting electromagnets provided along the storage ring and circulated, and are emitted when deflected. In the synchrotron radiation device, each of the deflecting electromagnets has a pair of magnetic pole parts facing each other in a direction perpendicular to the electron orbit plane with the electron orbit in between, and a pair of magnetic pole parts facing the center of the electron orbit. The whole is formed into a sector shape with a yoke part connecting around the axis, and the width of the yoke part in the direction perpendicular to the electron trajectory is set larger than the width of the magnetic pole part in the direction perpendicular to the electron trajectory. A synchrotron radiation device characterized by having an iron core. (2) The synchronizer according to claim 1, wherein the iron core is formed in a shape such that both end faces in the electron orbit direction intersect with the electron orbit at an angle of 90 degrees or less on the electron orbit plane. Tron radiation device.