Undulator

Abstract

To provide a long type (for example, the length of a magnet row is 2 m or more) variable polarization undulator that has two magnet rows facing each other with a predetermined gap in between, and performs polarization modulation by phase-driving the magnet rows, and that can withstand the attractive force acting on magnet arrays on opposing driving and stationary sides and can suppress manufacturing costs.SOLUTION: In a variable polarization undulator that has two magnet rows arranged opposite to each other with a predetermined gap in between, and performs polarization modulation by driving the phase of the magnet rows, among the magnet rows, one row that is movable in the phase direction is attached to and supported by a base via a support, and a part of the base includes a protrusion that protrudes toward another base side on which the other row attached to the one row is attached and supported, and a plurality of linear guides are installed on a plane of the base including the protrusion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an undulator (insertion source) installed in an electron storage ring or the like. [Background technology]

[0002] When an electron beam accelerated to nearly the speed of light in a vacuum is bent in a magnetic field, it emits radiation in the tangential direction of the electron beam's trajectory, which is called synchrotron radiation. A light source that generates this synchrotron radiation is installed in the straight section of an electron storage ring (electron beam storage ring), and research is being conducted to put various technologies into practical use that take advantage of its characteristics such as high directivity, high intensity, and high polarization. Today's electron storage rings are equipped with multiple undulators (insertion devices), which are high-brightness light sources with higher beam currents and smaller beam cross sections.

[0003] One type of undulator known is the APPLE (Advanced Planar Polarized Light Emitter)-II undulator (hereinafter APPLE-II), which is introduced in Non-Patent Document 1 and elsewhere. APPLE-II is a variable polarization undulator that has two rows of magnets arranged opposite each other with a predetermined gap between them, and performs polarization modulation by phase driving the magnet rows. For example, of the two rows of magnets facing each other, one above the other, 1 While maintaining the positional relationship of the pair of magnet rows, 1 By mechanically driving the pair of magnet rows in the direction of the electron beam (the direction of arrangement and phase of the magnet rows), the magnetic field on the electron orbit can be changed to generate horizontal linear polarization, left (right) circular polarization, and vertical linear polarization. APPLE-II is installed in large synchrotron radiation facilities such as SPring-8, and is usually a long type with a magnet row length of 2m or more.

[0004] The applicant has proposed in Patent Document 1 an undulator unit with a short magnet row length that can be used in undulators with a short magnet row length required for small synchrotron radiation facilities such as those found in research institutions such as universities, and in segmented APPLE-IIs that combine different polarized light generated by APPLE-II to obtain arbitrary polarized light, which is currently in demand.

[0005] Furthermore, Patent Document 2 discloses a structure in which, in a phase-driven undulator like APPLE-II, a magnet row is provided outside the driving magnet row to cancel the force in the driving direction, in order to drive the undulator at high speed in the phase direction without increasing the motor power. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-21493 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-203700 [Non-patent literature]

[0007] [Non-Patent Document 1] Kazuyoshi Kadono and three others, "Analysis of a New Variable Polarization Undulator," JAERI-M Report, Japan Atomic Energy Research Institute, August 1993, No. 93-156 Summary of the Invention [Problem to be solved by the invention]

[0008] In APPLE-II, the top and bottom 2Because the magnet rows of the two rows face each other, attractive forces are generated not only between the magnet rows facing each other in the vertical direction (gap direction) but also between the magnet rows facing each other in the horizontal direction (direction perpendicular to both the gap direction and the phase direction). Furthermore, APPLE-II requires a structure for driving the magnet rows not only in the gap direction but also in the phase direction. The undulator unit structure of Patent Document 1 has separate connecting beams on the drive side and the fixed side. The fixed-side connecting beam is connected to a support column by a saddle, and the drive-side connecting beam is connected to the fixed-side connecting beam by a phase drive mechanism. Since the magnet rows and supports can be fixed integrally to each connecting beam, the attractive forces generated in the horizontal direction are not a major problem. However, this structure was only possible because the undulator unit of Patent Document 1 has a short magnet row. In an undulator with a long magnet row, the drive-side magnet row and support are connected to the connecting beam by a linear guide and driven in the phase direction by a phase drive mechanism (see Figure 11). With this structure, as shown in Figure 11, an attractive force is applied to the magnet array on the drive side and the magnet array on the fixed side, which places an excessive load on the linear guide, causing the magnet array and support to tilt. For this reason, it would be desirable to make the support wider and provide multiple wide linear guides, but the presence of a vacuum pump in the width direction of the support makes it impossible to widen the support.

[0009] On the other hand, in the structure of Patent Document 2, the force that is cancelled is only in the phase direction, so the canceling force of the magnet array is also applied in the horizontal direction. For this reason, the moving base, which integrally connects the magnet array and support, is connected to the connecting beam by a linear guide, and linear guides are also installed on the side of the moving base to connect it to the connecting beam and surrounding components for reinforcement. However, for example, in a long-type undulator with a magnet array length of 2 m or more, installing linear guides on the side of the moving base as in the structure of Patent Document 2 makes it extremely difficult to assemble the device and increases the number of parts, thereby increasing manufacturing costs.

[0010] The present invention has been made in consideration of the above circumstances, and its object is to provide a long-type (e.g., magnet row length of 2 m or more) variable polarization undulator that has two rows of magnet rows arranged opposite each other with a predetermined gap between them and performs polarization modulation by phase driving the magnet rows, which can withstand the attractive forces acting on the opposing drive side and fixed side magnet rows and can reduce manufacturing costs. [Means for solving the problem]

[0011] The undulator according to the present invention, which has been made to solve the above problems, comprises: A variable polarization undulator has two rows of magnets arranged opposite each other with a predetermined gap between them, and performs polarization modulation by phase-driving the magnet rows. One of the magnet rows that is movable in the phase direction is attached to and supported by a base via a support, a part of the base has a protruding portion protruding toward another base to which another row of the bases is attached and supported, the other row of the bases being arranged next to the one row of the bases; A plurality of linear guides are installed on the plane of the base including the protrusion.

[0012] The undulator according to the present invention is A variable polarization undulator has two rows of magnets arranged opposite each other with a predetermined gap between them, and performs polarization modulation by phase-driving the magnet rows, a first driving magnet row and a first fixed magnet row arranged side by side; a first driving magnet support and a first fixed magnet support to which the first driving magnet row and the first fixed magnet row are attached and supported; and a second driving magnet support and a first fixed magnet support to which the first driving magnet support and the first fixed magnet support are attached and supported. 1 Drive base and 1 A fixed base and a second fixed magnet row and a second driving magnet row that face the first driving magnet row and the first fixed magnet row across a gap; a second fixed magnet support and a second driving magnet support to which the second fixed magnet row and the second driving magnet row are attached and supported; and a third fixed magnet support and a second driving magnet support to which the second fixed magnet support and the second driving magnet support are attached and supported. 2 Fixed base and 2 A driving base; a first connecting beam that is integrally connected to the first fixed base and is connected to the first driving base via a plurality of linear guides so as to be relatively movable; The second fixed base is integrally connected to the 2 a second connecting beam connected to the drive base via a plurality of linear guides so as to be relatively movable; the first driving base and the second driving base have a first stepped portion and a second stepped portion that protrude toward the first fixed base and the second fixed base, Of the plurality of linear guides, a portion of the linear guides on the side of the first fixed base and the second fixed base is 1 fixed to the top of the stepped portion and the second stepped portion; It is characterized by:

[0013] The first fixed base and the second fixed base have a third stepped portion and a fourth stepped portion formed to be recessed corresponding to the first stepped portion and the second stepped portion.

[0014] The undulator is The first drive magnet row and the second drive magnet row, and the first fixed magnet row and the second fixed magnet row are arranged diagonally opposite each other, 、 The first drive magnet row is arranged to move the magnets relative to the first fixed magnet row. column a first phase driving mechanism that drives the 1 It is attached to the connecting beam, The second drive magnet row is arranged to move the magnets relative to the second fixed magnet row. columna second phase driving mechanism that drives the second connecting beam in the arrangement direction is attached to the second connecting beam.

[0015] The undulator is the first driving base relative to the first fixed base The aforementioned Magnet array Array of a first phase driving mechanism that drives the second driving base in a direction relative to the second fixed base; The aforementioned Magnet array Array of a second phase driving mechanism that drives in the direction; a gap drive mechanism for driving the first drive magnet support and the first fixed magnet support, and / or the second fixed magnet support and the second drive magnet support in a direction in which the magnets face each other, in order to change the size of the gap; 1 series The collimated beam and the 2 consecutive a drive interlocking mechanism for connecting at least one of the connecting beams to the gap drive mechanism, Multiple pillars and The gap includes a vacuum chamber through which an electron beam passes, and the vacuum tank A vacuum pump is connected to the

[0016] The first drive magnet support and the first fixed magnet support are 1 The drive base and the 1 It is attached to and supported by a fixed base either directly or via a mounting plate. [Effects of the Invention]

[0017] According to the present invention, in a long-type variable polarization undulator (e.g., a magnet row length of 2 m or more) having two rows of magnets arranged opposite each other with a predetermined gap between them and performing polarization modulation by phase driving the magnet rows, it is possible to provide an undulator that can withstand the attractive forces acting on the opposing drive side and fixed side magnet rows and can reduce manufacturing costs. [Brief explanation of the drawings]

[0018] [Figure 1]FIG. 1 is a front perspective view of an undulator 100 according to an embodiment of the present invention. [Figure 2] FIG. 1 is a rear perspective view of an undulator 100 according to an embodiment of the present invention. [Figure 3] FIG. 1 is a front view of an undulator 100 according to an embodiment of the present invention. [Figure 4] FIG. 2 is a rear view of the undulator 100 according to the embodiment of the present invention. [Figure 5] FIG. 1 is a right side view of an undulator 100 according to an embodiment of the present invention. [Figure 6] 4 is a cross-sectional view taken along the line AA in FIG. 3. [Figure 7] FIG. 4 is an enlarged view of the magnet array and its vicinity in the AA cross section of FIG. [Figure 8] FIG. 10 is a diagram showing the connection of the undulator 100 according to the embodiment of the present invention by a linear guide (an enlarged schematic cross-sectional view of the vicinity of the second drive magnet row MD2). [Figure 9] FIG. 10 is an enlarged perspective view of the vicinity of the first drive magnet row MD1, the first fixed magnet row MF1, the second drive magnet row MD2, and the second fixed magnet row MF2, for explaining the movement of the magnet rows. [Figure 10] FIG. 2 is a cross-sectional view showing a state in which the gap of the undulator 100 according to the embodiment of the present invention is closed. [Figure 11] FIG. 10 is a diagram illustrating the connection of a conventional undulator using a linear guide. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention relates to a variable polarization undulator that has two rows of magnets arranged opposite each other with a predetermined gap between them, and performs polarization modulation by phase driving the magnet rows, and in particular to a long type variable polarization undulator in which the length of the magnet rows is 2 m or more, or a long type in which multiple support columns are arranged. The undulator of the present invention will be explained below with reference to the drawings. In the following explanation, the figures in the drawings will be used to explain the undulator of the present invention. X The direction is the phase direction, YThe direction is called the Gap direction (vertical direction), and the Z direction in the figure is called the horizontal direction.

[0020] Figure 1 is a front perspective view of an undulator 100 according to one embodiment of the present invention, and Figure 2 is a rear perspective view. In Figure 1 and other drawings of the present application, unless otherwise specified, the gap σ between the magnet rows is shown open so that the structure can be easily understood. For convenience in the explanations in this specification, the side on which the support columns 65 are arranged will be referred to as the rear of the undulator 100, and the opposite side (the side on which the magnet rows are arranged) will be referred to as the front, but this does not limit the installation direction of the undulator 100.

[0021] Fig. 3 is a front view of an undulator 100 according to an embodiment of the present invention, and Fig. 4 is a rear view. Fig. 5 is a right side view of the undulator 100 according to an embodiment of the present invention, Fig. 6 is a cross-sectional view taken along line AA in Fig. 3, and Fig. 7 is an enlarged view of the vicinity of the magnet array. In these figures, the vacuum pump connected to the vacuum chamber is omitted.

[0022] As shown in FIG. 6, the undulator 100 includes a first drive magnet row M in which a number of magnets are arranged in a row. D 1. A first fixed magnet row MF1, a second fixed magnet row MF2, and a second drive magnet row MD2, which also have a large number of magnets arranged in a row, face each other across a gap δ. A vacuum chamber 51 is placed in this gap space, and an electron beam passes through the vacuum chamber 51.

[0023] First, the configuration around these magnet rows will be described with reference to FIG. 1 Drive magnet array M D1 and the first fixed magnet array M F1, second fixed magnet row M F2 and the second drive magnet array M D2 are arranged side by side in close proximity. D 1 and 2nd fixed magnet array M F2, first fixed magnet row M F1 and second drive magnet array M D2 face each other across a gap δ. MD1 and the second drive magnet row MD2, and the first fixed magnet row MF1 and the second fixed magnet row MF2 are positioned diagonally opposite each other (positioned so as to intersect each other). 1 Drive magnet array M D1, the first fixed magnet array MF1, the second fixed magnet array MF2, and the second drive magnet array MD2 are respectively the first drive magnet support 1, the first fixed magnet support 3, the second fixed magnet support 4, and the second drive magnet array support 2 and are integrally connected to the first drive base 5, the first fixed base 7, the second fixed base 8, and the second drive base 6 via a mounting plate 9 using appropriate mechanical means (for example, bolts and nuts). The first drive magnet support 1, the first fixed magnet support 3, the second fixed magnet support 4, and the second drive magnet array support 2 may also be connected directly to the first drive base 5, the first fixed base 7, the second fixed base 8, and the second drive base 6, respectively, without using the mounting plate 9.

[0024] The first driving base 5 and the second driving base 6 are connected to a first connecting beam 16 and a second connecting beam 17, respectively, via a plurality of linear guides, for example, in the example of Fig. 7, a first front-side linear guide 11 and a first rear-side linear guide 12, and a second front-side linear guide 13 and a second rear-side linear guide 14. The first fixed base 7 and the second fixed base 8 are integrally connected to the first connecting beam 16 and the second connecting beam 17, respectively.

[0025] The connecting beam sides of the first driving base 5 and the second driving base 6 are respectively provided with a first fixed base 7 and a second fixed base 8. 1 The stepped portion 5a and the second stepped portion 6a are provided, which increases the width of the portion where the first front side linear guide 11, the first rear side linear guide 12, the second front side linear guide 13, and the second rear side linear guide 14 are installed. 1A portion of the rear-side linear guide 12 is located above the first stepped portion 5a and therefore above the first fixed magnet array MF1, and a portion of the second front-side linear guide 13 is located below the second stepped portion 6a and therefore below the second fixed magnet array MF2. The magnet array sides (mounting plate 9 sides) of the first fixed base 7 and the second fixed base 7 have third stepped portions 7a and fourth stepped portions 8a that are recessed to correspond to the first stepped portions 5a and second stepped portions 6a.

[0026] As the linear guide, it is preferable to use a known structure using a circulating ball mechanism (for example, a product name LM guide). Alternatively, a known cross roller guide can be used. Depending on the width of the first drive base 5, the second drive base 6, and the width of the linear guide to be used, 3 More than two linear guides may be connected. 3 In the above cases, in the following description, the frontmost linear guides will be referred to as the first front side linear guide and the second front side linear guide, and the rearmost linear guides will be referred to as the first rear side linear guide and the second rear side linear guide.

[0027] The first phase driving mechanism 21 is connected to the first connecting beam 16, and the second phase driving mechanism 22 is connected to the second connecting beam 17. The first phase driving mechanism 21 and the second phase driving mechanism 22 each include a motor 23, a conversion unit 24, a ball screw 25, a bracket 26, a guide plate 27, and a linear guide 28.

[0028] The gap drive mechanism 31 includes a drive interlocking mechanism 32, a motor 33, and conversion units 34 and 35, and the drive interlocking mechanism 32 includes a ball screw 36 and a slider 37. The movements of the first phase drive mechanism 21, the second phase drive mechanism 22, and the gap drive mechanism 31 will be briefly explained later.

[0029] These mechanisms are placed on a plurality of support columns 65, or are connected to various members to support the mechanisms, and are placed on a platform 61. The platform 61 is placed on a support surface by a plurality of pedestals 62.

[0030] No.1 Drive magnet array M A vacuum chamber 51, which is a path for the electron beam, is arranged between D1 and the first fixed magnet row MF1 and the second fixed magnet row MF2 and the second drive magnet row MD2, and the vacuum chamber 51 is connected to a vacuum pump 53 through a pump chamber 52. The pump chamber 52 is supported on a frame 61 by a support 63. A support member 64 is provided on the support 63 and supports the lower part of the pump chamber 52. These are connected by appropriate mechanical means (for example, bolts and nuts).

[0031] The effects of the structure of the present invention will be described below. 2 FIG. 11 is a further enlarged cross-sectional view (schematic view) of the vicinity of the drive magnet array MD2, showing that the drive base 70 in a conventional undulator is connected to the connection beam 73 via a linear guide 71. In the conventional undulator, the drive base 70 and the fixed base 72 have the same width. With a typical undulator size and such a structure, it is necessary to use a narrow linear guide. 2 This is the best that can be done to connect them properly, and there is a risk that the linear guide will not be able to withstand the attractive force between the magnet rows acting in the direction of the arrow (horizontal direction), causing the magnet rows to tilt.

[0032] In contrast, in the undulator of the present invention, 1 The first drive base 5 and the second drive base 6 are 1 The stepped portion 5a and the second stepped portion 6a increase the width of the linear guide installation surface, making it possible to connect multiple wide linear guides, which can withstand the horizontal attractive force between the magnet rows and prevent the magnet rows from tilting.In addition, assembling the device is not difficult and the number of parts is not increased, manufacturing costs can be reduced.

[0033] Next, the movement of the magnet array will be explained. Figure 9 is an enlarged perspective view of the magnet array and its vicinity from the front perspective view. The vacuum system, such as the vacuum chamber, has been omitted from Figure 9. Also, like the second drive magnet array MD2 and second fixed magnet array MF2, the first drive magnet array MD1 and first fixed magnet array MF1 are lined up in large numbers in the direction of the magnet array, but in Figure 9 they are hidden behind the first drive magnet support 1 and first fixed magnet support 3, which are installed to cover the ends of the magnet array.

[0034] The first phase drive mechanism 21 moves the first drive magnet array MD1 and the first drive magnet support 1, which are connected to the first connecting beam 16 via the first front-side linear guide, the first rear-side linear guide, the first drive base 5, and the mounting plate 9, in the direction of the arrow in the figure, and similarly, the second phase drive mechanism 22 moves the second drive magnet array MD2 and the second drive magnet support 2, which are connected to the second connecting beam 17 via the second front-side linear guide, the second rear-side linear guide, the second drive base 6, and the mounting plate 9, in the direction of the arrow in the figure. The example in Figure 9 shows the first drive magnet array MD1 and the second drive magnet array MD2 moved in the phase direction, to the left as viewed from the front of the undulator 100, relative to the first fixed magnet array MF1 and the second fixed magnet array MF2.

[0035] A known method such as that described in JP 2019-175766 A can be used as a method for phase-driving the first drive magnet row MD1 and the second drive magnet row MD2 by the first phase drive mechanism 21 and the second phase drive mechanism 22. This will be briefly described in this specification with reference to Figures 3, 6, etc.

[0036] The first phase drive mechanism 21 has a motor 23, a conversion unit (worm gear) 24 that converts the direction of transmission of the drive of the motor 23 by 90°, and a ball screw 25 that is rotationally driven by the motor 23 and the conversion unit 24. The ball screw 25 is connected to a guide plate 27 via a bracket 26, and the guide plate 27 is 1 It is integrally connected to the drive base 5 and is connected to the first 1 The motor 23 is connected to the connecting beam 16. By this structure, the first1 Driving base 5 and 1 The first drive shaft 5 is connected to the drive base 5. 1 The drive magnet array MD1 can be moved. A limiter 29 is provided to stop the first drive base 5 at a predetermined position. The second phase drive mechanism 22 also moves in a similar manner, so a description thereof will be omitted.

[0037] A known method described in International Publication No. 2018 / 143253 or the like can be used to adjust the size of the gap σ by the gap drive mechanism 31. This specification will briefly explain this method with reference to Figures 1, 5, etc.

[0038] The gap drive mechanism 31 includes a motor 33 and converters 34 and 35. The converters 34 and 35 convert the direction of drive transmission by 90°. The drive interlocking mechanism 32 includes a ball screw 36. The saddles 18 and 19 are connected to the ball screw 36 via a slider 37. Changing the position of the saddles 18 and / or 19 determines the positions of the first connecting beam 16 and the second connecting beam 17 in the gap direction, and therefore the positions of the first drive magnet row MD1 and the first fixed magnet row MF2 and the second fixed magnet row MF2 and the second drive magnet row MD2 in the gap direction. Therefore, by driving the gap drive mechanism 31 (transmitting the rotation of the motor 33 to the drive interlocking mechanism 32 via the converters 34 and 35 to rotate the ball screw 36), at least one of the saddles 18 and 19 can be moved to change the size of the gap σ. A limiter 38 is installed to stop the saddles 18 and 19 at a predetermined position.

[0039] Figure 10 shows the state in which the gap σ is closed by the gap drive mechanism 31. When the undulator 100 is operated, the gap σ is closed in this manner. The size of σ is adjusted as needed. Also, when necessary, such as during maintenance, the gap σ can be opened as shown in Figures 1 to 9.

[0040] For convenience, the drawings in this specification show the first connecting beam 16 on the upper side and the second connecting beam 17 on the lower side, but they may be reversed. Furthermore, the support columns 65 are arranged vertically and the magnet rows are arranged horizontally, but this is not limited to the directions shown in the drawings. For example, the support columns 65 may be arranged horizontally or diagonally, and the magnet rows may be arranged vertically or diagonally. [Industrial Applicability]

[0041] The present invention has industrial applicability in that it can provide an undulator that can withstand the attractive forces acting on the opposing drive and fixed magnet rows and can reduce manufacturing costs in a long-type variable polarization undulator (e.g., a magnet row length of 2 m or more) that has two magnet rows arranged opposite each other with a predetermined gap between them and performs polarization modulation by phase driving the magnet rows. [Explanation of symbols]

[0042] 100 Undulator MD1 First drive magnet array MD2 Second drive magnet array MF1 1st fixed magnet row MF2 Second fixed magnet array 1 First drive magnet support 2 Second drive magnet support 3 First fixed magnet support 4 Second fixed magnet support 5. First drive base 5a First stepped section 6 Second drive base 6a Second stepped section 7 First fixed base 7a Third stepped section 8 Second fixed base 8a 4th stepped section 9 Mounting plate 11 First front linear guide 12 First rear linear guide 13 Second front linear guide 14 Second rear linear guide 16 First connecting beam 17 Second connecting beam 21 First phase drive mechanism 22 Second phase drive mechanism 31 Gap drive mechanism 32 Drive linkage mechanism 51 Vacuum chamber 61 Mounting stand

Claims

1. A variable polarization undulator has two rows of magnets arranged opposite each other with a predetermined gap between them, and performs polarization modulation by phase-driving the magnet rows, One of the magnet rows that is movable in the phase direction is attached to and supported by a base via a support, a part of the base has a protruding portion protruding toward another base to which another row of the bases is attached and supported, the other row of the bases being arranged next to the one row of the bases; A plurality of linear guides are installed on a plane of the base including the protrusion. An undulator characterized by:

2. A variable polarization undulator having two rows of magnets arranged opposite each other with a predetermined gap therebetween, and performing polarization modulation by phase-driving the magnet rows, a first drive magnet row and a first fixed magnet row arranged side by side; a first drive magnet support and a first fixed magnet support to which the first drive magnet row and the first fixed magnet row are attached and supported; and a first drive base and a first fixed base to which the first drive magnet support and the first fixed magnet support are attached and supported; a second fixed magnet row and a second driving magnet row that face the first driving magnet row and the first fixed magnet row across a gap, a second fixed magnet support and a second driving magnet support to which the second fixed magnet row and the second driving magnet row are attached and supported, and a second fixed base and a second driving base to which the second fixed magnet support and the second driving magnet support are attached and supported; a first connecting beam integrally connected to the first fixed base and connected to the first driving base via a plurality of linear guides so as to be relatively movable; a second connecting beam that is integrally connected to the second fixed base and connected to the second driving base via a plurality of linear guides so as to be relatively movable; the first driving base and the second driving base have first and second stepped portions protruding toward the first fixed base and the second fixed base, and the first and second fixed bases have third and fourth stepped portions formed to be recessed corresponding to the first and second stepped portions, Among the plurality of linear guides, portions of the linear guides on the first fixed base and second fixed base sides are fixed to upper portions of the first stepped portion and the second stepped portion. An undulator characterized by:

3. the first drive magnet row and the second drive magnet row, and the first fixed magnet row and the second fixed magnet row are arranged diagonally opposite to each other, a first phase driving mechanism that drives the first driving magnet row relative to the first fixed magnet row in an arrangement direction of the magnet row is attached to the first connecting beam; a second phase driving mechanism attached to the second connecting beam for driving the second drive magnet row relative to the second fixed magnet row in the arrangement direction of the magnet rows; 3. The undulator according to claim 2, wherein the undulator is a sphere.

4. a first phase driving mechanism that drives the first driving base relative to the first fixed base in the arrangement direction of the magnet row, and a second phase driving mechanism that drives the second driving base relative to the second fixed base in the arrangement direction of the magnet row; a gap drive mechanism for driving the first drive magnet support and the first fixed magnet support, and / or the second fixed magnet support and the second drive magnet support in a direction in which the magnets face each other, in order to change the size of the gap, and a drive interlocking mechanism for connecting at least one of the first connecting beam and the second connecting beam with the gap drive mechanism, Multiple pillars and 4. The undulator according to claim 2, further comprising a vacuum chamber in the gap for passing the electron beam, and a vacuum pump connected to the vacuum chamber.

5. 5. An undulator according to claim 2, wherein the first drive magnet support and the first fixed magnet support are attached to and supported by the first drive base and the first fixed base directly or via an attachment plate.

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