Replacement mechanism for capillaries and x-ray diffraction apparatus

Abstract

This replacement mechanism replaces a capillary, which is located at a measurement position, during measurement by a transmission method using an X-ray diffraction apparatus. Holders are capable of holding, in one-to-one correspondence, a plurality of capillaries filled with samples. A first drive unit is capable of moving any of the plurality of capillaries to the measurement position. A second drive unit is capable of rotating a capillary located at the measurement position about an axis extending in the longitudinal direction of said capillary. The plurality of capillaries are held in a positional relationship that enables measurement by the transmission method, with 2θ in the range of 0-160°, of a sample filled in the capillary located at the measurement position.

Description

Capillary exchange mechanism and X-ray diffractometer

[0001] The present invention relates to a capillary exchange mechanism and an X-ray diffractometer.

[0002] A sample stage for performing measurement by a transmission method using a capillary filled with a powder sample is known (for example, Patent Document 1 and Non-Patent Document 1).

[0003] Specification of Chinese Utility Model No. 219891127

[0004] Rigaku Journal, Volume 36(1), 2020, p.10-18

[0005] In the total scattering measurement by the transmission method, it is necessary to perform measurement in a wide 2θ range. However, in the technique of Patent Document 1, a wide 2θ range may not be ensured. Further, in the technique of Non-Patent Document 1, since the sample stage holds one capillary, when performing measurement using a plurality of capillaries, the user needs to manually exchange to another capillary each time the measurement using one capillary is completed. Therefore, there is a risk of increasing the work load of the user.

[0006] The present invention provides a technique having a 2θ range capable of total scattering measurement by the transmission method and reducing the work load of the user in measurement using a plurality of capillaries.

[0007] The present invention may include the following embodiments: [Embodiment 1] An exchange mechanism for exchanging a capillary located at a measurement position in a transmission measurement using an X-ray diffraction apparatus, comprising: a plurality of holders capable of holding a plurality of capillaries filled with a sample in a one-to-one correspondence; a first drive unit capable of moving any of the plurality of capillaries to the measurement position; and a second drive unit capable of rotating the capillary located at the measurement position around an axis extending in the longitudinal direction of the capillary, wherein each of the plurality of capillaries, when moved to the measurement position, is positioned higher vertically than the other capillaries. [Embodiment 2] The exchange mechanism according to Embodiment 1, further comprising a mounting portion to which the plurality of holders are detachably attached, wherein the first drive unit moves a capillary held in any of the plurality of holders to the measurement position by driving the mounting portion. [Aspect 3] An exchange mechanism according to aspect 2, wherein the first drive unit rotates the mounting unit with a horizontally extending rotation axis as the center of rotation. [Aspect 4] An exchange mechanism according to aspect 3, wherein the plurality of holders are arranged on the circumference of a circle centered on the rotation axis of the mounting unit. [Aspect 5] An exchange mechanism according to any one of aspects 1 to 4, wherein the second drive unit includes one drive source and a transmission unit that transmits the rotation of the one drive source only to the holder among the plurality of holders that holds the capillary located at the measurement position. [Aspect 6] An exchange mechanism according to aspect 5, wherein the second drive unit is provided so as not to be moved by the first drive unit. [Aspect 7] An exchange mechanism according to aspect 5, wherein the transmission unit includes a magnetic coupling. [Aspect 8] An exchange mechanism according to any one of aspects 1 to 7, wherein each of the plurality of holders has a support portion that supports the capillary on both sides of the part of the capillary to be measured.[Aspect 9] An exchange mechanism according to any one of aspects 1 to 8, wherein the first drive unit includes a first drive source, the second drive unit includes a second drive source, the first drive source and the second drive source are arranged vertically, and the second drive source is positioned above the first drive source. [Aspect 10] An exchange mechanism according to aspect 9, further comprising a support member for supporting the first drive source and the second drive source. [Aspect 11] An X-ray diffractometer comprising: an exchange mechanism according to any one of aspects 1 to 10; an X-ray source for irradiating a sample filled in a capillary located at the measurement position with X-rays; and a detector for detecting X-rays diffracted by the sample.

[0008] According to the present invention, it is possible to provide a technology that has a 2θ range that enables total scattering measurement by transmission method, and that reduces the workload of the user in measurements using multiple capillaries.

[0009] Schematic diagram of an X-ray diffractometer according to one embodiment Perspective view of the exchange mechanism according to one embodiment Perspective view of the exchange mechanism in Figure 2 with the cover removed Side view of the holder holding the capillary according to one embodiment Cross-sectional view of the holder viewed from the same direction as in Figure 4A Front view schematically showing the mounting part according to one embodiment Diagram schematically showing the measurable 2θ range of the sample filled in the capillary at the measurement position Figure showing an exchange mechanism as a comparative example regarding the arrangement of multiple capillaries Diagram schematically showing the work schedule during measurement when using the exchange mechanism according to one embodiment Diagram schematically showing the work schedule during measurement when using a sample stage without an exchange mechanism

[0010] Embodiments of the invention will be described below with reference to the drawings. In this specification, the term "direction" includes both "positive direction" and "negative direction," and has a different meaning from "orientation." Therefore, when the term "predetermined direction" is used, the orientation is not limited. On the other hand, if the term is "+X direction," the orientation is limited to positive, and if the term is "-X direction," the orientation is limited to negative.

[0011] [X-ray Diffractometer 1] Figure 1 is a schematic diagram of an X-ray diffractometer 1 according to one embodiment. The X-ray diffractometer 1 includes a replacement mechanism 2, an X-ray source 3, and a detector 4. The replacement mechanism 2 is a mechanism for replacing a capillary located at the measurement position P1. Details will be described later. The X-ray source 3 irradiates the sample to be measured with X-rays. In this embodiment, the irradiation direction of the X-rays from the X-ray source 3 is horizontal (Y direction). In this embodiment, by moving the detector 4 within a predetermined range on the circumference of a circle C1 centered on the measurement position P1, it is possible to perform transmission-based measurement within a predetermined 2θ range. When adjusting 2θ, it is also possible to fix the position of the detector 4 and move the X-ray source 3, or to move both the detector 4 and the X-ray source 3. However, it is preferable to fix the position of the X-ray source 3 and move only the detector 4. By using such a configuration, the positional relationship between the X-ray source 3 and the sample is fixed, so that the sample can be stably irradiated with X-rays.

[0012] Furthermore, it is preferable that there are no obstacles above the measurement sample (the sample filled in a capillary at the measurement position P1). Specifically, it is preferable that there are no obstacles above the measurement sample, in the region through which the detector 4 passes when it moves along the circumference of circle C1, and in the region between the moving detector 4 and the measurement sample. With such a configuration, it is possible to perform transmission measurements up to a high angle of 2θ with the X-ray source 3 fixed. Here, a high angle of 2θ means 90° or more. As shown in Figure 1, when the X-ray irradiation direction is horizontal, if there is an obstacle above the measurement sample, it becomes difficult to measure at the position where 2θ is 90°. For example, if there is an obstacle in region R1 (above the measurement sample) shown in Figure 6, it is difficult to measure at the position where 2θ is 90°, but if there is no obstacle in region R1, it is possible to measure at the position where 2θ is 90°. Also, depending on the type of measurement, it may be necessary to measure up to a higher angle, so it is more preferable that it is possible to measure up to 2θ of 160°. To achieve this, the detector 4 can be configured so that there are no obstacles in the region through which the detector 4 passes when it moves along the circle C1 between 0 and 160° 2θ, or in the region between the moving detector 4 and the sample being measured.

[0013] Furthermore, it is preferable that the low-angle 2θ range can also be measured. That is, the 2θ range in which the X-ray diffractometer 1 can measure by transmission may be at least 0 to 90°, or it may be 0 to 160°. In addition, the X-ray diffractometer 1 may be capable of various measurements, such as reflection measurements, by appropriately selecting the sample stage. In this embodiment, the X-ray source 3 does not move and the detector 4 moves, but configurations in which the X-ray source 3 moves and the detector 4 does not, or configurations in which both the X-ray source 3 and the detector 4 move can also be adopted.

[0014] [Exchange Mechanism 2] <Overview> Figure 2 is a perspective view of an exchange mechanism 2 according to one embodiment. Figure 3 is a perspective view of the exchange mechanism 2 in Figure 2 with the cover 26 removed. The exchange mechanism 2 is a mechanism for exchanging a capillary located at the measurement position P1 in a transmission measurement using an X-ray diffraction apparatus 1. The exchange mechanism 2 includes a plurality of holders 21a to 21f, a mounting part 22, an orbital drive part 23, a rotational drive part 24, a support part 25, and a cover 26. The exchange mechanism 2 also includes a fixing part 27 that rotatably supports the mounting part 22. Although not shown, the exchange mechanism 2 may include a control unit that controls the operation of the orbital drive part 23 and the rotational drive part 24 based on instructions from an external information processing device, and an encoder that detects the rotational position of the mounting part 22 rotated by the orbital drive part 23.

[0015] <Holder 21> Multiple holders 21a to 21f are capable of holding multiple capillaries 5a to 5f filled with samples in a one-to-one correspondence. When describing matters common to multiple holders 21a to 21f, they will simply be referred to as holder 21. Similarly, when describing matters common to multiple capillaries 5a to 5f, they will simply be referred to as capillary 5.

[0016] In this embodiment, six capillaries 5a to 5f are held by six holders 21a to 21f, but the number of holders can be changed as appropriate, and may be two to five or seven or more. As will be described later, the number of capillaries 5 located at the measurement position can be set within a range in which measurement by transmission method is possible within a predetermined 2θ range.

[0017] Figure 4A is a side view of a holder 21 holding a capillary 5 according to one embodiment. Figure 4B is a cross-sectional view of the holder 21 viewed from the same direction as in Figure 4A. The holder 21 has a main body portion 211 and support portions 212 and 213 that support the capillary 5 on both sides of the measurement portion 51 of the capillary 5. Multiple bearings 214 are provided between the main body portion 211 and the support portions 212 and 213, and the support portions 212 and 213 are rotatable relative to the main body portion 211. In this embodiment, O-rings 215 for holding the capillary 5 are provided on both the support portions 212 and 213, so that the capillary 5 can be held stably. In addition, a magnet 24231 which constitutes a transmission portion 242 described later is provided on the support portion 212.

[0018] <Mounting Section 22> Refer to Figure 5 in conjunction with Figure 3. Figure 5 is a schematic front view showing the mounting section 22 according to one embodiment. The mounting section 22 is a part to which a plurality of holders 21a to 21f are detachably attached. In this embodiment, the holders 21 can be attached to six mounting positions 221a to 221f of the mounting section 22. For example, the mounting positions 221a to 221f may have openings, grooves, etc. that can engage with the holders 21. In this embodiment, the holders 21 are attached to the mounting section 22 such that the longitudinal direction of the capillary 5 held by the holder 21 extends in the horizontal direction (X direction in the figure).

[0019] In this embodiment, the mounting portion 22 includes three parts 222 to 224. Part 222 is a disc-shaped portion on the front (+X side) of the mounting portion 22, and is provided with openings into which the holder 21 can be inserted, corresponding to mounting positions 221a to 221f. These openings have a shape corresponding to the main body portion 211 of the holder 21, and can support the main body portion 211 at mounting positions 221a to 221f. Part 223 is a cylindrical portion with a smaller diameter than part 222, connected to the -X side of part 222, and has a groove formed in it into which the lower part of the main body portion 211 of the holder 21 can slide, corresponding to mounting positions 221a to 221f. In part 223, a groove is formed instead of an opening at the position corresponding to mounting positions 221a to 221f, so the holder 21 is supported with the part to be measured 51 of the capillary 5 exposed. Part 224 is a cylindrical part with a larger diameter than part 223, connected to the -X side of part 223, and is provided with recesses into which the holder 21 can be inserted, corresponding to mounting positions 221a to 221f. When the holder 21 is inserted from the +X side of the mounting part 22, it passes through the opening of part 222 and the groove of part 223 and abuts against the recess of part 224, thereby defining the position of the holder 21 in the X direction. In addition, a pulley for the transmission part 232 of the orbital drive part 23, which will be described later, is provided on the outer circumferential surface of part 224.

[0020] In this embodiment, the holder 21 can be attached to and detached from the mounting portion 22 by moving the holder 21 in one direction (X direction), making the attachment and detachment operation easy and facilitating automation of attachment and detachment by robots or the like. Furthermore, since the holder 21 can be attached to and detached from the mounting portion 22, the holder 21 can be attached to the mounting portion 22 without directly touching the delicate capillary 5. Therefore, since delicate work is not required when attaching the holder 21 holding the capillary 5 to the mounting portion 22, the structure facilitates automation of attachment and detachment by robots or the like, where delicate work is difficult.

[0021] Furthermore, a configuration in which the mounting portion 22 and the holder 21 are integrated can also be adopted. In this case, the measurement sample can be placed by inserting the capillary 5 into multiple holders integrated with the mounting portion 22. Also, as will be described later, since the mounting portion 22 rotates (revolves) by the orbital drive unit 23, the configuration in which the mounting portion 22 and the holder 21 are integrated can also be said to be a configuration in which the components that rotate (revolve) by the orbital drive unit 23 can directly hold the capillary 5.

[0022] Furthermore, in this embodiment, the mounting portion 22 is rotatably supported with respect to an axial fixing portion 27 extending in the X direction. More specifically, the mounting portion 22 rotates with respect to the fixing portion 27 about a rotation axis AX1 extending in the horizontal direction (X direction in the figure) by a revolution drive unit 23, which will be described later. The mounting positions 221a to 221f of the mounting portion 22 are arranged on the circumference of a circle C2 centered on the rotation axis AX1 of the mounting portion 22. In other words, circle C2 corresponds to the trajectory of the mounting positions 221a to 221f. More specifically, the capillaries 5 held by the holders 21 mounted at the mounting positions 221a to 221f are arranged on the circumference of a circle C2 centered on the rotation axis AX1 when viewed from the X direction (when viewed from the viewpoint in Figure 5).

[0023] <Orbital Drive Unit 23> The first drive unit moves one of the multiple capillaries to the measurement position. In this embodiment, an example is shown in which the orbital drive unit 23 is used as the first drive unit. The orbital drive unit 23 can move one of the multiple capillaries 5a to 5f to the measurement position P1. Here, the rotation of the multiple capillaries 5a to 5f around the rotation axis AX1 is referred to as orbit. In this embodiment, the orbital drive unit 23 moves one of the multiple capillaries 5a to 5f to the measurement position P1 by driving the mounting part 22. More specifically, the orbital drive unit 23 rotates the mounting part 22 with the rotation axis AX1, which extends in the horizontal direction, as the center of rotation.

[0024] The orbital drive unit 23 includes a drive source 231 such as a motor, and a transmission unit 232 that transmits the rotation of the drive source 231 to the mounting unit 22. In this embodiment, the transmission unit 232 transmits the rotation of the drive source 231 to the mounting unit 22 by a belt pulley mechanism. However, other known technologies can be appropriately used as the transmission unit 232. Also, the rotation axis AX of the mounting unit 22 and the rotation axis of the drive source 231 may be coaxial.

[0025] Figure 6A schematically shows the measurable 2θ range of the sample filled in the capillary 5 at the measurement position P1. Figure 6A shows the capillary 5a, held by the holder 21 attached to the mounting position 221a, in the position at the measurement position P1. X-rays irradiated from the X-ray source 3 are diffracted by the sample filled in the capillary 5a at the measurement position P1. The diffracted X-rays are detected by the detector 4.

[0026] In this embodiment, multiple capillaries 5 are held by multiple holders 21 in a positional relationship that allows for transmission measurement of a sample filled in a capillary 5a located at the measurement position P1 within a 2θ range of 0 to 160°. Specifically, the measurement position P1 and mounting positions 221a to 221f are set so that the capillaries 5b to 5f and the holders 21b to 21f holding them do not interfere with the X-ray path PA1 from the X-ray source 3 to the measurement position P1 and with region R1. This enables transmission measurement within a 2θ range of 0 to 160°.

[0027] Furthermore, in this embodiment, when each of the multiple capillaries 5a to 5f is moved to the measurement position P1, it is positioned higher vertically (in the Z direction in the figure) than the remaining capillaries and higher than the position of capillary 5 that is not located at the measurement position P1. In the example of Figure 6A, when capillary 5a, which is included in the multiple capillaries 5a to 5f, is moved to the measurement position P1, it is positioned higher vertically (in the Z direction in the figure) than the remaining capillaries 5b to 5f. This suppresses interference between the capillaries 5b to 5f and the holders 21b to 21f that hold them on the path PA1 and region R1 when X-rays are irradiated horizontally (in the Y direction in the figure) from the X-ray source 3 to the capillary 5a at the measurement position P1. More specifically, the upper ends of the remaining capillaries 5b to 5f are positioned lower vertically than the vertical center of capillary 5a at the measurement position P1. The relative positions of the measurement position P1 and the capillaries 5a to 5b can be appropriately changed within a range that ensures a 2θ range of 0 to 160°.

[0028] For example, in this embodiment, the measurement position P1 is a position shifted in the +Y direction from the highest point of circle C2, but it may be the highest point or a position shifted in the -Y direction from the highest point. Also, for example, the trajectory of the mounting positions 221a to 221f when the mounting part 22 moves does not have to be strictly circular, but may be elliptical or racetrack-shaped, for example.

[0029] Furthermore, in this embodiment, when one of the multiple capillaries 5a to 5f is located at the measurement position P1, the remaining capillaries are located at one of the standby positions P2 to 5. Also, all of the standby positions P2 to P5 are located lower than the measurement position P1 in the vertical direction. In the example in Figure 6A, capillary 5a is located at the measurement position P1, and capillaries 5b to 5f are located at standby positions P2 to P6, respectively. Then, for example, when the mounting part 22 rotates (revolves) and capillary 5b is located at the measurement position P1, capillaries 5c to 5f and 5a are located at standby positions P2 to P6, respectively. Thus, in this embodiment, the absolute positions of the measurement position P1 and standby positions P2 to P6 are constant, and regardless of which of the multiple capillaries 5a to 5f is located at the measurement position P1, the remaining capillaries are located at one of the standby positions P2 to P6, respectively. Therefore, regardless of which of the multiple capillaries 5a to 5f is located at the measurement position P1, the remaining capillaries and the holders holding them do not interfere with the path PA1 and region R1. Consequently, for all of the multiple capillaries 5a to 5f, measurement by transmission method is possible within a 2θ range of 0 to 160°.

[0030] Figure 6B shows a replacement mechanism 902 as a comparative example regarding the arrangement of multiple capillaries. The replacement mechanism 902 is capable of holding multiple capillaries 905a to 905f in a vertically aligned manner. The replacement mechanism 902 can then move vertically to position one of the capillaries 905a to 905f at the measurement position P1, thereby allowing the capillary located at the measurement position P1 to be replaced. In this configuration, if the second and subsequent capillaries 905b to 905f from the top are located at the measurement position P1, the capillaries above them will interfere with region R1, making it impossible to perform transmission-based measurements in the 2θ range of 0 to 160°.

[0031] In contrast, in this embodiment, since the capillaries 5a to 5f move along the circle C2, regardless of which capillary 5 is located at the measurement position P1, the remaining capillaries 5 will be located vertically below the capillary 5 located at the measurement position P1. This is because, as mentioned above, the measurement position P1 is located vertically higher than the standby positions P2 to P6, and the absolute positions of the measurement position P1 and standby positions P2 to P6 do not change. This makes it possible to perform measurements using the transmission method in a 2θ range of 0 to 160°.

[0032] <Rotation Drive Unit 24> The second drive unit rotates the capillary located at the measurement position around an axis extending in the longitudinal direction of the capillary. Refer to Figures 3 and 4B. In this embodiment, an example is shown in which the rotation drive unit 24 is used as the second drive unit. The rotation drive unit 24 can rotate the capillary 5 located at the measurement position P1 around an axis extending in the longitudinal direction of the capillary 5. Here, the rotation of the capillary 5 around a rotation axis AX2 that is parallel to the longitudinal direction of the capillary 5 and passes through the capillary 5 itself is referred to as rotation. The rotation drive unit 24 includes one drive source 241 such as a motor, and a transmission unit 242 that transmits the rotation of one drive source 241 to a holder 21 among a plurality of holders 21 that holds the capillary 5 located at the measurement position P1. That is, in this embodiment, the capillary 5 that is not located at the measurement position P1 does not rotate. On the other hand, even if any of the multiple capillaries 5 are located at the measurement position P1, one drive source 241 can rotate only the capillary 5 located at the measurement position P1.

[0033] If a mechanism for rotating each of the multiple capillaries 5 is provided, it may lead to an increase in the number of parts and a larger device. In contrast, in this embodiment, a single drive source 241 can rotate the capillaries 5 regardless of which of the multiple capillaries 5 is located at the measurement position P1, thus simplifying the structure of the device and contributing to weight reduction and cost reduction. Furthermore, if a mechanism for rotating each of the multiple capillaries 5 is provided, for example, it may be necessary to provide a drive source on the movable mounting part 22, which may make the device configuration more complex. One of the features of this embodiment is that the rotation drive unit 24, which is the second drive unit, is provided so as not to be moved by the revolution drive unit 23, which is the first drive unit. That is, the rotation drive unit 24, which is the second drive unit, does not move. This simplifies the structure of the device.

[0034] In this embodiment, the transmission unit 242 includes a shaft member 2421, a belt pulley mechanism 2422, and a magnetic coupling 2423. The shaft member 2421 is a member that can rotate around a rotation axis parallel to the rotation axis of the drive source 241. The belt pulley mechanism 2422 transmits the rotation of the drive source 241 to the shaft member 2421. The magnetic coupling 2423 transmits the rotation of the shaft member 2421 to the holder 21 that holds the capillary 5 located at the measurement position P1. In other words, in this embodiment, the transmission unit 242 includes the magnetic coupling 2423.

[0035] The magnetic coupling 2423 is composed of a magnet 24231 provided on the support portion 212 of the holder 21 and a magnet 24232 provided on the shaft member 2421. The magnet 24231 provided on the support portion 212 of the holder 21 that holds the capillary 5 located at the measurement position P1 and the magnet 24232 provided on the shaft member 2421 are arranged to be in close proximity to each other. Furthermore, the magnet 24232 provided on the shaft member 2421 is provided so as to be in contact with the outer circumferential surface of the cylindrical portion 224 at a position radially outside the measurement position P1.

[0036] In this embodiment, the transmission unit 242 includes a magnetic coupling 2423, which allows the rotation of the drive source 241 to be transmitted to the support unit 212 of the holder 21 without contact. By employing a non-contact power transmission method, a single drive source 241 can rotate multiple capillaries 5 held by multiple holders 21. <Arrangement of drive source> The support unit 25 supports the drive source 231 and the drive source 241. In this embodiment, the drive source 231 and the drive source 241 are arranged vertically, with the drive source 241 positioned above the drive source 231. Since the drive source 231 and the drive source 241 are arranged vertically (X direction), it is possible to suppress the enlargement of the device in the width direction (Y direction). The drive source 231 and the drive source 241 may overlap in the Y direction in at least a portion of their respective parts, or one may be arranged so that the entirety of one fits within the width of the other in the Y direction.

[0037] Furthermore, since the drive source 231 and drive source 241 are supported by a single plate-shaped support member 2411, there is no need to provide separate members to support the drive source 231 and drive source 241, which can contribute to reducing the number of parts. In addition, although the drive source 231 and drive source 241 are provided on the same surface of the single plate-shaped support member 2411, the directions in which the output shafts extend are opposite to each other. With this configuration, interference between the transmission unit 232 and transmission unit 242 can be suppressed while preventing the device from becoming larger in the X direction.

[0038] <Work Schedule> Figure 7A schematically shows the work schedule during measurement when using the exchange mechanism 2 according to one embodiment, and Figure 7B schematically shows the work schedule during measurement when using a sample stage without the exchange mechanism 2.

[0039] Generally, total scattering measurements using the transmission method require several hours (for example, about 3 hours) for a single capillary 5. Therefore, when measuring multiple samples, for example, the user must manually change the samples every few hours (for example, about 3 hours). In contrast, when using the exchange mechanism 2 of this embodiment, six capillaries 5a to 5f can be installed in the exchange mechanism 2 at the start of the measurement, allowing for unattended measurement for about 18 hours. This reduces the workload on the user during measurement.

[0040] The present invention has been described above based on each embodiment. However, the present invention is not limited to the above embodiments, and modifications may be made without departing from the spirit of the invention. Furthermore, the technologies described in each embodiment may be combined as appropriate, or known technologies may be combined with the technologies of the above embodiments as appropriate.

[0041] 1 X-ray diffractometer, 2 exchange mechanism, 21 holder, 23 orbital drive unit, 24 rotation drive unit, 3 X-ray source, 4 detector, 5 capillary

Claims

1. An exchange mechanism for replacing a capillary located at a measurement position in a transmission measurement using an X-ray diffractometer, comprising: a plurality of holders capable of holding a plurality of capillaries filled with a sample in a one-to-one correspondence; a first drive unit capable of moving any of the plurality of capillaries to the measurement position; and a second drive unit capable of rotating the capillary located at the measurement position around an axis extending in the longitudinal direction of the capillary, wherein each of the plurality of capillaries, when moved to the measurement position, is positioned higher vertically than the other capillaries.

2. The exchange mechanism according to claim 1, further comprising a mounting portion to which the plurality of holders are detachably attached, wherein the first drive unit moves a capillary held in any of the plurality of holders to the measurement position by driving the mounting portion.

3. The exchange mechanism according to claim 2, wherein the first drive unit rotates the mounting unit with respect to a horizontally extending rotating shaft as the center of rotation.

4. The exchange mechanism according to claim 3, wherein the plurality of holders are arranged on the circumference of a circle centered on the rotation axis of the mounting portion.

5. An exchange mechanism according to any one of claims 1 to 4, wherein the second drive unit includes one drive source and a transmission unit that transmits the rotation of the one drive source only to the holder among the plurality of holders that holds a capillary located at the measurement position.

6. The exchange mechanism according to claim 5, wherein the second drive unit is provided so as not to be moved by the first drive unit.

7. The exchange mechanism according to claim 5 or 6, wherein the transmission part includes a magnetic coupling.

8. An exchange mechanism according to any one of claims 1 to 7, wherein each of the plurality of holders has a support portion for supporting the capillary on both sides of the portion of the capillary to be measured.

9. An exchange mechanism according to any one of claims 1 to 8, wherein the first drive unit includes a first drive source, the second drive unit includes a second drive source, the first drive source and the second drive source are arranged vertically side by side, and the second drive source is positioned above the first drive source.

10. The exchange mechanism according to claim 9, further comprising a support member for supporting the first drive source and the second drive source.

11. An X-ray diffraction apparatus comprising: an exchange mechanism according to any one of claims 1 to 10; an X-ray source for irradiating a sample filled in a capillary located at the measurement position with X-rays; and a detector for detecting X-rays diffracted by the sample.

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