X-ray analysis device
By adjusting the slit width using an asymmetric control unit and a cam mechanism, the problem of reduced X-ray intensity and increased background noise caused by improper slit width control in X-ray diffraction devices was solved, achieving uniform irradiation of the sample surface and improved analytical accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- RIGAKU CORP
- Filing Date
- 2022-01-10
- Publication Date
- 2026-06-16
Smart Images
Figure CN114813802B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an X-ray analysis apparatus. Background Technology
[0002] Patent Document 1 describes an X-ray diffraction apparatus having a rotating device that rotates a sample from a first position to a second position at a first angular velocity and a diffraction slit disposed between an X-ray source and the sample to allow the X-ray source to pass through a window of the rotating device. The X-ray diffraction apparatus rotates the diffraction slit at a second angular velocity slower than the first angular velocity so that the slit and the sample rotate together, making the irradiated portion of the sample substantially constant during rotation.
[0003] Patent document 2 describes a slit device that can not only restrict an X-ray beam to a specified width but also adjust the restricted width. The slit device has a pair of slit components, a cam follower component integrated with each slit component, and a cam that rotates between these cam follower components. The slit components are opened and closed by the rotation of the cam.
[0004] Existing technical documents
[0005] Patent documents
[0006] Patent Document 1: Japanese Patent Application Publication No. 50-63982
[0007] Patent Document 2: Japanese Patent Application Publication No. 8-262196 Summary of the Invention
[0008] The problem that the invention aims to solve
[0009] When the inventors of this invention assumed a scenario where X-rays in an X-ray diffraction device are incident on a sample at a low angle, as in the patent document above, they discovered that something less than ideal might happen by simply controlling the slit width of the diverging slit mechanism to make the irradiation width of the X-rays on the sample consistent with the width of the sample.
[0010] Figure 1 This diagram illustrates the geometric relationship in an X-ray diffraction apparatus when the slit width of the diverging slit mechanism DS is simply controlled so that the irradiation width W0 of the X-rays on the sample TG matches the width W of the sample. The diagram shows the situation where a beam LF of X-rays emitted from the X-ray source F, shaped by the diverging slit mechanism DS, irradiates a sample TG of width W at an angle θ to a goniometer head fixed at a predetermined distance.
[0011] Typically, the optical axis L of the beam LF is... C Adjusted to pass through the geometric center C of the sample TG. Therefore, the optical axis L is relative to the center C of the sample TG. CThe side where the angle formed by the sample surface and SF is an acute angle ( Figure 1 The optical axis L in C The lower left side (hereinafter referred to as "the front side of center C") of the beam divergence angle. With optical axis L C The side where the angle formed by the sample surface and SF is an obtuse angle ( Figure 1 The optical axis L in C The divergence angle of the beam (located on the upper right side, hereinafter referred to as "the inner side of center C"). They are usually equal and relative to the divergence angle of the beam LF itself.
[0012] [Formula 1]
[0013]
[0014] Established. Furthermore, for convenience, Figure 1 The sample surface SF of sample TG is represented as a virtual surface extending to the outside of sample TG.
[0015] Furthermore, the diverging slit mechanism DS is a mechanism that allows the slit width of the optical slit to be variable, and can be used with angles. The slit width is adjusted accordingly so that the irradiation width W0 of the beam LF in the sample surface SF is consistent with the width W of the sample TG.
[0016] At this point, the divergence angle The angle θ is usually very small (e.g., around 0.5° to 3°). Therefore, when the angle θ is large, the illumination width W1 on the front side of the center C and the illumination width W2 on the inside side of the center C can be considered to be roughly equal, and no special problems will occur.
[0017] However, when the angle θ is small (e.g., below 10°), such as Figure 1 As shown, the irradiation width W1 < the irradiation width W2 (in Figure 1 The text exaggerates the situation, stating that even if the diverging slit mechanism DS is controlled to be equal to the width W of the sample TG, an area R1 will be generated on the front side of the center C where the sample TG is not irradiated by the beam LF, and an area R2 will be generated on the inside side of the center C where the sample TG is irradiated by the beam LF.
[0018] Therefore, in order to avoid generating region R1, if the slit width of the diverging slit mechanism DS is increased, the divergence angle will be increased. This would cause region R2 to expand, resulting in X-rays irradiating components outside the sample TG, such as the sample stage, thus increasing background noise. Conversely, to avoid generating region R2, the slit width of the divergence slit mechanism DS can be reduced, thereby reducing the divergence angle. This would cause region R1 to expand, resulting in a larger area where the X-ray beam LF does not irradiate the sample TG, thus reducing the intensity of the diffracted X-rays to be detected. In any case, simply controlling the slit width of the diverging slit mechanism DS cannot simultaneously solve the problems of reduced diffracted X-ray intensity and increased background noise.
[0019] The present invention was made in view of the above circumstances, and its object is to prevent the decrease in the intensity of diffracted X-rays in an X-ray diffraction device while preventing the increase in background noise.
[0020] Solution for solving the problem
[0021] An X-ray analysis apparatus according to one aspect of the present invention comprises: a goniometer; a sample stage disposed at the rotation center of the goniometer; an X-ray source for irradiating a sample fixed on the sample stage with X-rays; an X-ray detector for detecting X-rays diffracted by the sample; and an opening and closing mechanism formed between a pair of shielding members, wherein the width of a slit through which the X-rays pass is variable by opening and closing the shielding members, the opening and closing mechanism having an asymmetric control unit that, relative to a straight line connecting the X-ray source or the X-ray detector and the rotation center, asymmetrically controls the opening width of the shielding members by means of one side of the shielding members and the other side of the shielding members, corresponding to the rotation angle of the goniometer.
[0022] In one aspect of the X-ray analysis apparatus, the opening and closing mechanism may also be a diverging slit mechanism for shaping the X-rays emitted by the X-ray source.
[0023] In an X-ray analysis apparatus according to one aspect of the present invention, the asymmetric control unit is a cam that rotates in conjunction with the rotation of the goniometer to control the width of the slit, and has a cam shape for driving the shielding member on one side that is different from the cam shape for driving the shielding member on the other side.
[0024] In one aspect of the X-ray analysis apparatus, the cam may also have a cylindrical surface that, when the rotation angle of the goniometer is 0 degrees or near the angle of the X-rays irradiating the sample stage from the X-ray source, makes the slit a certain width.
[0025] In one aspect of the X-ray analysis apparatus, the cam may further have a slit surface that keeps the width of the slit constant when the goniometer is rotated to a direction in which the angle of the X-rays irradiating the sample stage from the X-ray source is negative.
[0026] In one aspect of the X-ray analysis apparatus, the asymmetric control unit may further include a mechanism that symmetrically opens and closes the pair of shielding components from their fully closed position in accordance with the rotation angle of the goniometer, and a mechanism that moves the position of the pair of shielding components as a whole at least in a straight line direction perpendicular to the line connecting the X-ray source or the X-ray detector and the rotation center.
[0027] In an X-ray analysis apparatus according to one aspect of the invention, the asymmetric control unit can also control the width of the slit relative to a plurality of different α, corresponding to a rotation angle that is α times the rotation angle of the goniometer.
[0028] In one aspect of the X-ray analysis apparatus, the asymmetric control unit may further have a plurality of α values that are different from each other, such that the rotational speed of the cam rotates in a manner corresponding to a rotational angle that is α times the rotational angle of the goniometer. Attached Figure Description
[0029] Figure 1 This diagram illustrates the geometric relationship in an X-ray diffraction apparatus when the slit width of the diverging slit mechanism is simply controlled so that the irradiation width of the X-rays on the sample matches the width of the sample.
[0030] Figure 2 The following are schematic structural diagrams illustrating an example of an X-ray analysis apparatus according to an embodiment of the present invention: (a) is a block diagram showing the schematic system structure of the X-ray analysis apparatus, and (b) shows the schematic structure of the X-ray diffraction device included in the X-ray analysis apparatus.
[0031] Figure 3 This is a structural diagram showing the main components of an X-ray diffraction apparatus, including the goniometer, X-ray generator, and diverging slit mechanism.
[0032] Figure 4 From Figure 3 The IV-IV line orientation view includes the front view of the diverging slit mechanism of the asymmetric control unit.
[0033] Figure 5 The following diagrams illustrate examples of asymmetric control units implemented by various cam mechanisms: (a) shows a diagram with cams separately set in a pair of cam followers, and (b) shows a diagram where the cams are so-called cylindrical cams.
[0034] Figure 6 The following diagrams are provided to illustrate a more detailed design of the asymmetric control unit: (a) shows the shape and relationship of the cam and cam follower when the diverging slit mechanism is fully closed; (b) shows the case where the cam is rotated.
[0035] Figure 7 This is a graph showing the change in the rotation angle θ of the X-ray irradiation width on the sample surface in the diverging slit mechanism of this embodiment and the diverging slit mechanism of the comparative example.
[0036] Figure 8 The diagram illustrates a design example of an asymmetric control unit involved in a variation of this embodiment. (a) is a top view of the asymmetric control unit, and (b) is a bottom view. Figure 8 (a) Front view viewed along line VIIIB-VIIIB.
[0037] Figure 9 The diagram shows a design example of an asymmetric control unit used to illustrate a further variation of this embodiment. (a) shows an example where the cut surface is a continuous planar shape on a cylindrical surface, and (b) shows an example where the cut surface is a concave shape.
[0038] Figure 10 This is a diagram illustrating an example of the mechanism of an asymmetric control unit for another variation of this embodiment.
[0039] Figure 11 This is a graph showing the variation of the X-ray irradiation width on the sample surface relative to the rotation angle θ when using a diverging slit mechanism with a variable asymmetric control unit having a rotation speed ratio α between the rotary table and the rotation axis.
[0040] Figure 12 (a) represents the illumination width W1, angle θ, and divergence angle in front of center C. The diagram shows the relationship between the illumination width W2 inside the center C and the angle θ and divergence angle. A diagram showing the relationships between them.
[0041] Explanation of reference numerals in the attached figures
[0042] 1 Rotary stage, 2 Sample stage, 3 Shielding component, 4 Asymmetric control unit, 5 Rotary shaft, 6 Cam, 7 Cam follower, 8 Elastic component, 9 Electric motor, 10 Gearbox, 11 Rectangular section, 12 Semicircular section, 13 Cylindrical surface, 14 Cut surface, 15 Direct drive guide, 16 Threaded mechanism, 100 X-ray analysis device, 101 X-ray diffraction device, 102 Crystalline phase identification device, 103 Display device, 104 Goniometer, 105 X-ray generator, 106 Diverging slit mechanism, 107 X-ray detector, 108 Control unit, 109 Input / output device, 110 Sample Detailed Implementation
[0043] The following is for reference Figures 2 to 12 This invention describes the X-ray analysis apparatus 100 involved in the embodiments of the present invention.
[0044] Figure 2This is a schematic structural diagram illustrating an example of an X-ray analysis apparatus 100 according to an embodiment of the present invention. In the same figure, (a) is a block diagram illustrating the schematic system structure of the X-ray analysis apparatus 100, and (b) is a diagram illustrating the schematic structure of the X-ray diffraction device 101 included in the X-ray analysis apparatus 100.
[0045] Reference Figure 2 (a) The X-ray analysis apparatus 100 includes an X-ray diffraction apparatus 101, a crystalline phase identification apparatus 102, and a display device 103. Furthermore, the display device 103 may be, for example, a flat panel display device, and may be integrated with the crystalline phase identification apparatus 102.
[0046] The crystal phase identification device 102 includes an input unit 111, a storage unit 112, a resolution unit 113, and an output unit 114. The crystal phase identification device 102 can be implemented using a general computer. In this case, for example, the input unit 111 and output unit 114 may be configured with input / output interfaces, the storage unit 112 may be configured with a hard disk or memory, and the resolution unit 113 may be configured with a CPU. A database is stored in the storage unit 112. The database records data on the peak positions and peak intensity ratios in the 2θ-I curves of X-ray diffraction patterns of known multiple crystal phases, which are used as data on the distance d of the crystal planes to the intensity ratio I (dI data). The storage unit 112 can be an external hard disk, or it can utilize a cloud computing method, where an external server or other device capable of information communication via telecommunications lines such as the Internet performs some or all of the functions of the resolution unit 113 and the storage unit 112. Figure 2 (a) is a block diagram used to represent the system structure, and therefore is not limited to the physical location of the devices that perform the functions of the X-ray analysis apparatus 100 shown in each block.
[0047] The analysis unit 113 stores the X-ray diffraction data input from the X-ray diffraction apparatus 101 via the input unit 111 into the storage unit 112. Then, the analysis unit 113 processes the X-ray diffraction data stored in the storage unit 112, stores the processing results in the storage unit 112, and displays the processing results on the display device 103 via the output unit 114.
[0048] refer to Figure 2(b) The X-ray diffraction apparatus 101 includes a goniometer 104, an X-ray generator 105, a diverging slit mechanism 106, an X-ray detector 107, a control unit 108, and an input / output device 109. The goniometer 104 is a protractor with a sample stage (not shown) at its center, on which a sample 110 is mounted and rotates. X-rays generated from the X-ray generator 105 pass through the diverging slit mechanism 106, becoming a thin, ribbon-like beam that widens in a direction perpendicular to the plane of the paper in this figure, and irradiate the sample 110. The X-ray detector 107 detects the X-rays diffracted by the sample 110. When the angle between the X-ray irradiating the sample 110 and the lattice plane of the sample 110 is θ, the diffraction angle is 2θ. The control unit 108, composed of a computer, a sequencer, and dedicated circuitry, controls the goniometer 104, the X-ray generator 105, and the X-ray detector 107. The input / output device 109 inputs measurement conditions and other data to the control unit 108, and outputs the X-ray diffraction data detected by the X-ray detector 107 to the crystalline phase identification device 102. Moreover, the X-ray detector 107 is not limited to a two-dimensional detector, but can also be a structure that uses a zero-dimensional detector or a one-dimensional detector to move or rotate the sample 110 or the X-ray detector 107.
[0049] Figure 3 This is a structural diagram showing the main components of the X-ray diffraction apparatus 101, including the goniometer 104, the X-ray generator 105, and the diverging slit mechanism 106. Since the structure of the X-ray generator 105 itself has little relevance to the main points of this invention, detailed structural illustrations are omitted in this figure, and the X-ray source F within it is simply represented as a point source of X-rays. The X-ray source F itself, as shown in the figure, can be considered both a point source and a... Figure 3 The X-ray source F has a width in the vertical direction of the paper, and since this does not hinder the following explanation, there are no particular limitations. As the X-ray source F, a general X-ray tube can be used, which can be made of glass, ceramic, or other materials.
[0050] The goniometer 104 rotatably holds the sample 110, which is to be analyzed by X-rays, on the sample stage 2, which is located at the center of rotation of the rotary table 1. In this embodiment, viewed from the rotation axis of the rotary table 1, the sample stage 2 is configured to be at the center of rotation O of the rotary table 1. G The geometric center C of the sample surface of the sample 110 held on the sample stage 2 is aligned with that of the sample surface. Therefore, from the rotation center O G The distances to both ends of sample 110 are equal. Furthermore, Figure 3The relative rotation between the X-ray generating device 105, the divergence slit mechanism 106, and the sample 110 on the sample stage 2, as described above, can be either a structure where the rotating stage 1 of the goniometer 104 rotates, or a structure where the X-ray generating device 105 and the divergence slit mechanism 106 rotate relative to the rotating stage 1 of the goniometer 104; there is no difference between the two. Therefore, the rotation center O... G It is the center of relative rotation between the goniometer 104, the X-ray generator 105, and the diverging slit mechanism 106.
[0051] The diverging slit mechanism 106 is an opening and closing mechanism that allows the width of the slit formed between a pair of opposing shielding members 3 to be variable by opening and closing the aforementioned shielding members. Each pair of shielding members 3 has straight edges at their opposing ends and is made of a material such as metal that has X-ray blocking properties. By arranging the shielding members 3 with a small gap between them, the straight edges of the pair of shielding members 3 are positioned opposite each other with a small gap, thereby forming a slit through which X-rays pass. The X-rays are shaped into a thin, ribbon-like beam by passing through this slit, and the shape of the beam can be controlled by making the width of the slit variable through the diverging slit mechanism 106, which serves as the opening and closing mechanism for the pair of shielding members 3. Although there is no particular limitation on the specific shape of the straight edges, in this embodiment it is referred to as a blade edge. Furthermore, in the diverging slit mechanism 106 of this embodiment, the shielding members 3 on one side and the shielding members 3 on the other side are positioned relative to the connection between the X-ray source F and the rotation center O. G straight line FO G The opening width of the shielding component 3 is controlled asymmetrically in accordance with the incident angle of the X-ray.
[0052] Here, the opening width of the shielding component 3 refers to the opening width of the diverging slit mechanism 106 from the fully closed state to... Figure 3 The moving distances of each of the upper and lower shielding components 3 are shown. In this embodiment, when the diverging slit mechanism 106 is fully closed, the edge position of the shielding component 3 is located at the junction of the X-ray source F and the rotation center O. G straight line FO G Above, because the shielding component 3 is perpendicular to the straight line FO G The movement causes the edge of the shielding component 3 to intersect with the straight line FO. G The distance between them corresponds to the opening of the shielding component 3. Furthermore, the edge of the shielding component 3 is perpendicular to the straight line FO. G The distance between them refers to the distance between the edge perpendicular to the shielding component 3 and the straight line FO. G The straight line and the edge, and the straight line FO G The distance between their respective intersection points, which is related to the edge and the straight line FO G The shortest distance between them is the same, and equal to Figure 3The straight line FO in the plane shown G The distance between the top of the shielding member 3 and the shielding member 3. Furthermore, if the diverging slit mechanism 106 is fully closed, the edge position of the shielding member 3 when it is fully closed can be determined based on the virtual position of the shielding member 3, and it is not necessarily required that the diverging slit mechanism 106 be fully closed. This is because, as will be described later, sometimes the diverging slit mechanism 106 is not fully closed, but is always controlled to leave a slight gap.
[0053] Therefore, the opening width of the shielding component 3 relative to the straight line FO G The asymmetry between the shielding component 3 on one side and the shielding component 3 on the other side means that the edges of each pair of shielding components 3 are perpendicular to the straight line FO. G The distances between them are different. Figure 3 In the example shown, the straight line FO G The distance between the shielding component 3 on the upper side of the figure and the straight line FO G The distances between them and the shielding component 3 on the lower side of the diagram are different.
[0054] Furthermore, the diverging slit mechanism 106 includes an asymmetric control unit 4, which, through the shielding member 3 on one side and the shielding member 3 on the other side, is positioned relative to the straight line FO. G The opening width of the shielding component 3 is controlled asymmetrically. The specific configuration of the asymmetrical control unit 4 is not necessarily limited, and various mechanisms can be used. For example, a servo motor or stepper motor can be prepared to drive each of the pair of shielding components 3, and the position of the shielding component 3 can be independently controlled using a ball screw mechanism or worm gear mechanism. Alternatively, a single power source can be supplied to the motor, and the position of the shielding component 3 can be controlled using a suitable mechanical mechanism such as a cam mechanism or linkage mechanism. The former method has the advantage of being able to freely set the position of the shielding component 3, while the latter method can reduce the number of power sources, which is advantageous in terms of cost and space.
[0055] Here, the width of the slit formed by the diverging slit mechanism 106 is equal to the distance between the edges of the pair of shielding members 3 forming the slit. Therefore, the distance that each shielding member 3 moves from the fully closed state is equal to the sum of the opening widths of each shielding member 3. Hereafter, the width of this slit will be simply referred to as the slit width.
[0056] In this embodiment, an example using a cam mechanism will be described as the asymmetric control unit 4. The asymmetric control unit 4 includes a rotation shaft 5, a cam 6 fixed to the rotation shaft 5, a pair of cam followers 7 arranged opposite each other to clamp the cam 6, and an elastic component 8 such as a spring that applies force to push the cam followers 7 against the cam 6. Furthermore, Figure 4 From Figure 3The figure shows a front view of the diverging slit mechanism 106, including the asymmetric control unit 4, viewed along line IV-IV, and the components constituting the asymmetric control unit 4 are shown in the diagram. Figure 3 The positional relationship of the paper in the depth direction.
[0057] When the rotating shaft 5 rotates, the cam 6 rotates accordingly, and the cam follower 7 moves following the outer peripheral shape of the cam 6. The shielding member 3 is fixed to the cam follower 7, and the shielding member 3 moves along the outer peripheral shape of the cam 6, causing the width of the slit formed by the diverging slit mechanism 106 to change. Furthermore, a brief explanation is given in... Figure 3 Used in Figure 3 The guide member that restricts the movement of the cam follower 7 in the vertical direction on the paper is omitted from the illustration. Furthermore, although the shielding member 3 is shown as being directly fixed to the cam follower 7, the installation method is arbitrary if the shielding member 3 and the cam follower 7 are integrally fixed; they can also be fixed using other support members such as suitable arms. In this example, the contact surface with the cam 6 of the cam follower 7 is a smooth sliding surface, appropriately lubricated with lubricating oil or grease, but it is not limited to this; a ball bearing can also be used as the cam follower 7.
[0058] The asymmetric control unit 4, relative to the shielding component 3, in Figure 3 The middle part is arranged in the direction inside the paper. Figure 4 The cam 6 is positioned below the paper surface, so as not to obstruct the X-ray beam LF from the X-ray source F irradiating the sample 110. Furthermore, the outer peripheral shape of the cam 6 can be relative to the straight line FO. G It is asymmetrically controlled by a shielding member 3 on one side and a shielding member 3 on the other side. That is, the shielding member 3 on one side of the cam 6 of the asymmetrical control unit 4 is used to drive the diverging slit mechanism 106. Figure 3 The upper side Figure 4 The cam shape of the right-side shielding component 3) is similar to that used to drive the other side shielding component 3 (here is Figure 3 The lower side Figure 4 The cam shapes of the left-side shielding component 3) are different from each other.
[0059] In this embodiment, cam 6 is the rotation center O around the rotation axis 5. C A rotating plate cam, with a pair of cam followers 7 positioned at a distance from the center of rotation O. C The positions are 180 degrees symmetrical. Therefore, the cam shapes for driving the front shielding member 3 and the inner shielding member 3 are different. In this case, it means that the outer periphery shape of the cam 6, which is a plate cam, is relative to the rotation center O. C Non-point symmetry.
[0060] Furthermore, the cam mechanism of the cam 6 shown in this embodiment is an example of a cam mechanism constituting the asymmetric control unit 4. Moreover, as... Figure 5 As shown, the asymmetric control unit 4 can be realized by various cam mechanisms.
[0061] For example, such as Figure 5 As shown in (a), a cam 6 can be provided on each of a pair of cam followers 7, and the two cams 6 can rotate synchronously by a suitable mechanism. Figure 5 Example (a) shows a mechanism in which two cams 6 are connected by a gear mechanism, and the cams 6 rotate synchronously when power is supplied to either gear. In addition, a timing belt or other transmission belt mechanism or a power shaft can also be used.
[0062] Or, such as Figure 5 As shown in (b), a pair of cam followers 7 can be simultaneously driven by a so-called cylindrical cam, i.e., cam 6. When power is supplied to cam 6 and it rotates about the cylindrical axis, the position of the cam followers 7 is controlled corresponding to the shape of the grooves engraved on its surface. Of course, it is also possible to use... Figures 3-5 The position of the cam follower 7 is controlled by a cam 6 in a form other than the example shown. In any case, by making the shapes of the individual cam faces of the cams 6 that drive the pair of cam followers 7 different from each other, the position of the cam follower 7 relative to the straight line FO of the diverging slit mechanism 106 can be controlled. G The positions of the shielding component 3 on one side and the shielding component 3 on the other side are controlled asymmetrically.
[0063] Return to Figure 3 The rotational power from the electric motor 9 is transmitted via the gearbox 10 to the rotary table 1 of the goniometer 104 and the rotation shaft 5 of the asymmetric control unit 4. The gearbox 10 is a speed reducer, which, by controlling the rotation of the electric motor 9, can adjust the rotation angle θ of the rotary table 1 within a range of at least 0 to 90 degrees. Here, the rotation angle θ of the rotary table 1 is determined by the rotation center O connecting the X-ray source F and the rotary table 1. G The angle between the straight line and the sample surface of sample 110 represents the angle θ. When the angle θ is 0°, X-rays irradiate the sample surface from the front side of sample 110 parallel to the sample surface. When the angle θ is 90°, it is equivalent to X-rays irradiating the sample surface of sample 110 perpendicularly.
[0064] Furthermore, in this example, the rotary table 1 and the rotating shaft 5 rotate synchronously at the same speed. That is, when the rotary table 1 rotates by only an angle θ, the rotating shaft 5 also rotates by only an angle θ. However, the speed ratio between the rotary table 1 and the rotating shaft 5 can be arbitrary, and the cam surface shape of the cam 6 can correspond to the rotation angle θ of the rotary table 1.
[0065] Furthermore, despite Figure 3 Not shown, but rotational power from motor 9 is also supplied to Figure 2 The X-ray detector 107 shown is rotated around the center O. G Rotation. The X-ray detector 107 rotates around the rotation center O of the rotary stage 1. G Centered on the X-rays (linear FO) irradiating the sample 110 G Since the rotation angle is 2θ, the ratio of the angular velocities of the rotational power supplied to the rotary table 1 and the X-ray detector 107 is 1:2.
[0066] Furthermore, since the goniometer 104's rotating stage 1, the diverging slit mechanism 106, and the X-ray detector 107 can be rotated while maintaining the aforementioned geometrical positional relationship, it is not necessary to rotate the goniometer 104 as shown in this example. Alternatively, for example, the goniometer 104 can be fixed, and the diverging slit mechanism 106 itself can be positioned relative to the rotation center O. G The rotation angle -θ, etc., can be any two rotating structures among the X-ray generator 105, the diverging slit mechanism 106, the sample 110, and the X-ray detector 107.
[0067] Next, refer to Figure 6 This will illustrate a more detailed design of the asymmetric control unit 4 shown in this example. Figure 6 (a) is a diagram showing the shape and relationship of the cam 6 and the cam follower 7 when the angle θ is 0°, i.e., the diverging slit mechanism 106 is fully closed. In addition, for reference, the shielding member 3 is represented by a dashed line in this diagram.
[0068] Cam 6 has an angle θ = 0°, and its major axis is aligned with the optical axis of the X-ray. Figure 3 straight line FO G The figure shows a rectangular portion 11 with a uniform elongated oval shape, and semicircular portions 12A and 12B, whose diameters are equal to the width of the rectangular portion 11, connected to its left and right ends. Furthermore, the rotation center of the cam 6 is the same as the rotation center O of the rotation shaft 5. C To the center O of the semicircular part 12A A Distance d up to A And to the center O of the semicircular part 12B B Distance d up to B They are different from each other, becoming d A >d B .
[0069] Therefore, cam 6 is relative to the rotation center O C Asymmetrical, and located at the center of rotation O in this diagram. C The one on the left is used to drive the straight line FO G The cam shape of the shielding component 3 on one side and located at the rotation center O CThe cam shape on the right side, which drives the shielding component 3 on the other side, is different. In this example, d B Designed to be more than d A Approximately 12% smaller value (in) Figure 6 (This difference is exaggerated in Chinese).
[0070] Figure 6 (b) indicates the case where the cam 6 is rotated. Here, it shows the state where the angle θ increases, the cam 6 rotates, and the cam follower 7 moves in a direction that separates from each other. At this time, as shown in the figure, the opening a of the shielding member 3 on one side... A The opening a of the shielding component 3 on the other side is larger than that of the other side. B .
[0071] This design controls the irradiation width of the X-ray sample surface irradiated from the X-ray source F to be consistent with the width and height of the sample 110. Figure 7 The graph shows the variation of the X-ray irradiation width on the sample surface of the sample 110 with rotation angle θ when using the diverging slit mechanism 106 with the asymmetric control unit 4 of this embodiment and in a comparative example where the opening of the shielding member 3 of the diverging slit mechanism 106 is equal on the front and inner sides without using the asymmetric control unit 4.
[0072] In this figure, the horizontal axis represents the range of rotation angle θ from 0° to 10°, and the vertical axis represents the changes in the X-ray irradiation width W1 on the front side, the irradiation width W2 on the inner side, and the overall irradiation width W0, respectively, using half the width W of the sample 110 and the overall width as proportions. The three curves shown as dashed lines in the figure represent the changes in irradiation width in the comparative example, and appear to be a single curve due to overlap, but the three curves shown as solid lines represent the changes in irradiation width in this embodiment.
[0073] Dashed line a represents the front irradiation width W1 in the comparative example, dashed line b represents the inner irradiation width W2 in the comparative example, and dashed line c represents the overall irradiation width W0 in the comparative example. As shown in the figure, when the angle θ is less than 3°, the X-ray irradiation width increases, and X-rays also irradiate parts outside the sample 110, thus a significant increase in background noise can be predicted. Moreover, in the range of approximately 5° and above, as shown by dashed line c, the irradiation width W0 is roughly consistent with the sample width W, but as shown by dashed line a, the front irradiation width W1 is about 6% shorter than half the sample width W / 2. Since there are unirradiated areas at the edges of the sample 110, it can be seen that the intensity of diffracted X-rays decreases. Furthermore, as shown by dashed line b, it can be seen that the inner irradiation width W2 is about 7% longer than half the sample width W / 2, and X-rays irradiate the sample stage and other parts outside the sample 110, thus increasing the background noise.
[0074] In contrast, the solid lines d, e, and f, which respectively represent the variations in the front irradiation width W1, the inner irradiation width W2, and the overall irradiation width W0 of this embodiment, largely overlap. Throughout the entire range of the rotation angle θ from 0° to 10°, half the width W of the sample 110 and its overall height are consistent. The magnitude of the deviation between half the width W of the sample 110 and the overall height is at most less than 0.2% in the front irradiation width W1 and the inner irradiation width W2, and at most less than 0.1% in the overall irradiation width W0. In fact, there is no area on the sample surface of the sample 110 that is not irradiated by X-rays, and in fact, no X-rays irradiate the outer side of the sample 110. Therefore, it is possible to suppress the decrease in diffracted X-ray intensity while preventing the increase in background noise.
[0075] Figure 8 The diagram illustrates a design example of the asymmetric control unit 4 involved in a variation of this embodiment. (a) is a top view of the asymmetric control unit 4, and (b) is a bottom view of the asymmetric control unit 4. Figure 8 The front view shown in (a) along line VIIIB-VIIIB. Furthermore, Figure 8 (b) also indicates that in Figure 8 In (a), the rotating shaft 5 and the elastic component 8 are omitted from the illustration. In this modified example, a cylindrical surface 13 is provided on the cam 6 when the angle θ is 0° and in the vicinity therein, which contacts the contact surface of the cam follower 7. The center of this cylindrical surface 13 is aligned with the rotation center O. C Consistent, and the diameter of the cylindrical surface 13 is slightly larger than the width of the rectangular portion 11 of the cam 6 and the diameter of the semicircular portions 12A and 12B, and protrudes slightly from the side of the rectangular portion 11 (in Figure 8 In the illustration, the diameter of the cylindrical surface 13 is depicted in an exaggerated manner (the diameter is exaggerated compared to the actual diameter). The angle θ between the cam follower 7 and the cylindrical surface 13 can be set arbitrarily, but as an example, it can be around ±1° to 2°.
[0076] Therefore, when the angle θ is in the range of 0° and its vicinity, the gap between the pair of cam followers 7 is pushed apart by the cylindrical surface 13, the shielding member 3 opens slightly, and the diverging slit mechanism 106 opens to the slit width a. i The opening is open. Moreover, as the cam 6 rotates further, the cam follower 7 contacts the semicircular portions 12A and 12B, and the shielding member 3 opens under control. Therefore, in this modified example, the diverging slit mechanism 106 will not be completely closed.
[0077] By setting up such a cylindrical surface 13, when the rotation angle θ of the goniometer 104 is at or near 0°, a thin X-ray of a certain width can be irradiated onto the sample stage 2, so that the preparatory work such as the alignment or calibration of the positions of each device can be carried out smoothly during the installation or maintenance of the X-ray analysis device 100.
[0078] Figure 9 This diagram illustrates a design example of the asymmetric control unit 4 involved in a further modification of this embodiment. In this modification, in addition to the modifications described above, the cam 6 rotates at a negative angle θ, i.e., the cam 6 at... Figure 9 A cut surface 14 is provided at a rotation angle in the counterclockwise direction and at a position opposite to the cam follower 7. This cut surface 14 is used to prevent the rectangular portion 11 or the semicircular portions 12A, 12B from contacting and pushing open the cam follower 7 when the cam 6 rotates in the negative direction, thereby increasing the slit width of the diverging slit mechanism 106.
[0079] Figure 9 (a) shows an example where the cut surface 14 is a planar shape continuous with the cylindrical surface 13, and (b) shows an example where the cut surface 14 is a concave shape. Of course, the shape of the cut surface 14 can also be other than that shown here. By providing the cut surface 14, the rotation angle θ of the cam 6 is within a specified negative range, for example, around -5°, and the slit width of the diverging slit mechanism 106 is the slit width a when the rotation angle θ is kept at 0°. i .
[0080] As described above, in cases where a one-dimensional detector is used, such as an X-ray detector 107, the reason for setting the cut surface 14 is that when the rotating table 1 rotates at a certain speed within a range from 0° to positive, the diverging slit mechanism 106 can be opened in the run-up interval before the angular velocity is constant, without irradiating excess X-rays.
[0081] Figure 10 This is a diagram illustrating an example of the mechanism of the asymmetric control unit 4 involved in another variation of this embodiment. Figure 10 The asymmetric control unit 4 shown is Figures 3 to 9 The mechanisms shown differ in that the cam shapes of the shielding member 3 on one side and the shielding member 3 on the other side, which drive the cam 6, are symmetrical. That is, the shielding member 3 is symmetrical about the rotation center O of the rotation axis 5. C It opens and closes symmetrically. On the other hand, this mechanism operates by rotating at the center O perpendicular to the connection point between the X-ray source F and the goniometer. G straight line FO G The direction corresponds to the rotation angle θ, making the rotation center O C Its own movement, relative to the straight line FO G Asymmetrical control of the shielding component 3 on one side and the shielding component 3 on the other side.
[0082] More specifically, aside from the cam shape of cam 6, Figure 10 The asymmetric control unit 4 shown includes the rotating shaft 5, cam 6, cam follower 7, and elastic component 8. Figures 3 to 9The mechanism shown has the same function and structure. The cam shape of cam 6 is as described above. Since the cam shapes for driving the shielding member 3 on one side and the shielding member 3 on the other side are symmetrical, the pair of shielding members 3 are in a fully closed position relative to the diverging slit mechanism 106 (in this example, relative to the rotation center O). C (Simultaneously) Perform opening and closing actions symmetrically.
[0083] Furthermore, the entire cam mechanism, including the rotating shaft 5, is perpendicular to the straight line FO. G It is movably supported in the direction of movement. Figure 10 In the example, the rotating shaft 5 is movably supported by a direct-drive guide 15 and a threaded mechanism 16. The direct-drive guide 15 can be a so-called linear guide, and its type is arbitrary. As an example, a commercially available optical single-axis stage can be used to fix the entire cam mechanism containing the rotating shaft 5 onto the same stage, etc. Furthermore, the threaded mechanism 16 is used to ensure that the entire cam mechanism containing the rotating shaft 5 is perpendicular to the straight line FO. G An example of a drive mechanism that precisely drives in a specific direction is a nut that moves in the axial direction corresponding to the rotation of a threaded shaft to which the rotational power is input from the transmission 10. By fixing the rotating shaft 5 to the nut, the cam mechanism containing the rotating shaft 5 moves as a whole as the nut moves.
[0084] The rotational power from the electric motor 9 is transmitted via the gearbox 10, which is then shifted as needed and input to the rotating shaft 5 and the threaded mechanism 16. This mechanism causes a pair of shielding members 3 to open and close symmetrically from their fully closed position in relation to the rotation angle θ of the rangefinder, and by positioning the entire pair of shielding members 3 at least perpendicular to the line FO. G Moving in the direction of, the shielding component 3 on one side and the shielding component 3 on the other side relative to the straight line FO G Asymmetric control.
[0085] In addition, the above Figure 10 The mechanism shown is an example of an asymmetric control unit 4 for implementing a similar system, and various variations can be implemented. That is, the asymmetric control unit 4 only needs to have a mechanism that allows a pair of shielding members 3 to open and close symmetrically from their fully closed positions, and at least ensure that the overall position of the pair of shielding members 3 is perpendicular to the line FO. G Any mechanism that moves in a direction is acceptable; the specific structure of each mechanism is not limited. For example, as a mechanism that symmetrically opens and closes a pair of shielding parts 3 from their fully closed position, in addition to... Figure 10 Besides the cam mechanism shown, linkage mechanisms and other mechanisms can also be used. Even when using a cam mechanism, other mechanisms can be employed. Figure 5 The institutions shown and other institutions.
[0086] Moreover, in addition to Figure 10 Apart from the threaded mechanism 16 shown, the position of the pair of shielding members 3 as a whole is at least perpendicular to the straight line FO. G The mechanism for directional movement can also use cam mechanisms, linkage mechanisms, and other mechanisms. Instead of inputting rotational power from the electric motor 9 via the transmission 10, a dedicated electric motor is used, which can control the position of the pair of shielding components as a whole in accordance with the rotation angle θ. Furthermore, the position of the pair of shielding components 3 as a whole can be defined here as... Figure 10 The midpoint of the line segment connecting the tops of a pair of shielding members 3 within the paper's surface. Furthermore, this mechanism is at least perpendicular to the straight line FO. G Directional movement means that the overall positional movement of the pair of shielding components 3 of this mechanism is at least perpendicular to the straight line FO. G The directional component. Therefore, the overall position of a pair of shielding components 3 can be relative to the straight line FO. G Moving diagonally does not necessarily mean moving in a straight line.
[0087] Furthermore, the X-ray analysis apparatus 100 of this embodiment can control the slit width of the diverging slit mechanism 106 in relation to a plurality of different α values, corresponding to a rotation angle that is α times the rotation angle of the goniometer 104.
[0088] In other words, according to this embodiment, the diverging slit mechanism 106 controls the slit width via the asymmetric control unit 4, such that the beam of X-rays irradiated from the X-ray source F is aligned with the width W of the sample 110 on the sample stage 2 at a rotation angle θ relative to the rotation angle θ of the rotary table 1 of the goniometer 104. As an example, the cam shape of the cam 6, driven by the rotating shaft 5 which rotates synchronously with the rotary table 1 at a constant speed, determines the slit width of the diverging slit mechanism 106 of the pair of shielding members 3 relative to the rotation angle θ.
[0089] Therefore, the asymmetric control unit 4 is activated to control the slit width of the diverging slit mechanism 106 relative to αθ. That is, although the actual rotation angle of the rotating stage 1 of the goniometer 104 is angle θ, the slit width of the diverging slit mechanism 106 is controlled so that the rotation angle of the rotating stage 1 is exactly αθ.
[0090] In the structure of the above embodiment, relative to the rotation angle θ of the rotating platform 1 of the goniometer 104, the rotation shaft 5 of the asymmetric control unit 4 of the diverging slit mechanism 106 only needs to be rotated by an angle α times αθ. Specifically, the above action can be achieved by controlling the rotating platform 1 and the rotation shaft 5 separately with independently provided motors, or by... Figure 3 The transmission 10 shown achieves this by making the reduction ratios of the rotational power input from the electric motor 9 to the rotary table 1 and the rotary shaft 5 different.
[0091] When using the gearbox 10, the above action can be achieved by changing the gearbox 10 itself according to the ratio α of the rotation speed of the rotary table 1 and the rotary shaft 5, or by setting a mechanism in the gearbox 10 to make the gear ratio variable, selecting multiple preset values of α that are different from each other, or the value of α can be continuously changed within a certain range.
[0092] As a mechanism that allows the transmission 10 to select multiple preset, arbitrarily different α values, a transmission of the so-called engagement clutch type, also used in motorcycles, can preferably be used. Moreover, as a mechanism that can continuously change the α value within a certain range, a so-called CVT (Continuously Variable Transmission) mechanism used in four-wheeled vehicles, etc., can also be appropriately used.
[0093] The rationale for this is that by controlling the slit width of the diverging slit mechanism 106 in accordance with a rotation angle α times the rotation angle of the goniometer 104, the X-ray irradiation width W0 can be substantially varied relative to the sample 110 with different widths. More specifically, relative to the width W of the sample 110 initially envisioned (i.e., the target value of the X-ray irradiation width W0 when α = 1), when a sample 110 with a width of αW times the initial width is mounted on the goniometer 104, by controlling the slit width of the diverging slit mechanism 106 in accordance with a rotation angle α times the rotation angle of the goniometer 104, the X-ray irradiation width can be made consistent with αW0 with higher precision. Even if the value of θ is in a small area, X-rays can be irradiated onto the surface of the sample 110 without waste. This suppresses the decrease in diffracted X-ray intensity and prevents the increase in background noise caused by X-rays irradiating the outside of the sample 110.
[0094] Figure 11 This is a graph showing the variation of the X-ray irradiation width with rotation angle θ on the surface of the sample 110 when using a diverging slit mechanism 106 equipped with an asymmetric control unit 4 that allows the ratio α of the rotational speed of the rotating stage 1 to that of the rotating axis 5 to be variable. The graph shows three cases: α = 1, α = 1.25, and α = 0.6. Furthermore, the display format of the graph is similar to... Figure 7 same.
[0095] When α = 1, this indicates that the width of sample 110 is the same as the original design, W. Due to overlap, it appears as one piece, but the solid lines d, e, and f represent the variations in the front irradiation width W1, the inner irradiation width W2, and the overall irradiation width W0, respectively. These solid lines d, e, and f... Figure 7 As shown, all are highly consistent with the design target values. Furthermore, for reference, short dashed lines a, b, and c are used to represent the values... Figure 7 The variations in the front irradiation width W1, the inner irradiation width W2, and the overall irradiation width W0 in the same comparative example shown.
[0096] When α = 1.25, and the width of sample 110 is 25% larger than the design value W, the changes in the front irradiation width W1, the inner irradiation width W2, and the overall irradiation width W0 are represented by dashed lines g, h, and i, respectively. As read from dashed line g, the front irradiation width W1 is slightly smaller than the actual width of the front side of sample 110, and the inner irradiation width W2 is slightly larger than the actual width of the inner side of sample 110, but the overall irradiation width W0 is approximately 125%, consistent with the actual width of sample 110. Moreover, the deviations of the front irradiation width W1 and the inner irradiation width W2 relative to the width of sample 110 are at most about 1.7%, which will not cause obstacles in practical applications.
[0097] When α = 0.6, and the width of sample 110 is 40% smaller than the design value W, the changes in the front irradiation width W1, the inner irradiation width W2, and the overall irradiation width W0 are represented by dashed lines j, k, and l, respectively. As read from dashed line j, the front irradiation width W1 is slightly larger than the actual width of the front side of sample 110, and the inner irradiation width W2 is slightly smaller than the actual width of the inner side of sample 110. However, the overall irradiation width W0 is approximately 60%, consistent with the actual width of sample 110, as is the case when α = 1.25. Moreover, the deviations of the front irradiation width W1 and the inner irradiation width W2 relative to the width of sample 110 are at most about 3%, which is still not a problem in practical application.
[0098] Furthermore, regardless of the value of α, the irradiation width exhibits a substantially constant value relative to the value of θ, demonstrating that the slit width of the diverging slit mechanism 106 can be controlled without considering the value of θ. In this way, by controlling the slit width of the diverging slit mechanism 106 in accordance with a rotation angle corresponding to a rotation angle α times that of the goniometer 104, samples 110 of different widths can be easily processed.
[0099] Furthermore, by controlling the slit width of the diverging slit mechanism 106 by a rotation angle corresponding to α times the rotation angle of the goniometer 104, the width of the sample 110 can be treated as αW, which is equivalent to α times the design value W. This is generally true, regardless of the specific structure of the aforementioned asymmetric control unit 4. (See below for reference.) Figure 12 To explain. Figure 12 For reference Figure 1 The diagram illustrates the geometric relationships within the X-ray diffraction apparatus; therefore, based on this diagram, the symbol used to represent the diverging slit mechanism will be denoted as DS. Here, the slit width of the diverging slit mechanism DS is controlled to be αθ, which is α times the angle θ.
[0100] First, before explaining, as Figure 1 As shown, W0 = W1 + W2, and as already explained, the slit width of the diverging slit mechanism DS is controlled when the divergence angle of the beam LF is... When the angle is θ, W0 = W.
[0101] Here, we first consider the illumination width W1 in front of center C and the angle θ, as well as the divergence angle in front of center C, within the illumination width W0. The relationship. At this time, such as Figure 12 As shown in (a), the intersection of the edge of the beam LF in front of the center C and the sample surface SF is set as A1, and the perpendicular line falling from the center C relative to the straight line FA1 is set as B1. Furthermore, the length between the X-ray source F and the center C is set as R. At this time, because...
[0102] [Formula 2]
[0103]
[0104] Thus obtain
[0105] [Formula 3]
[0106]
[0107] Similarly, considering the illumination width W2 and angle θ inside center C, as well as the divergence angle inside center C... Relationships, such as Figure 12 As shown in (b), the intersection of the edge of the beam LF inside the center C and the sample surface SF is set as A2, and the perpendicular line falling from the center C relative to the straight line FA2 is set as B2. At this time, because...
[0108] [Formula 4]
[0109]
[0110] Thus obtain
[0111] [Formula 5]
[0112]
[0113] Here, if we consider the reciprocals of W1 and W2, then
[0114] [Formula 6]
[0115]
[0116] Furthermore, by unfolding the molecules above, because and Therefore, it can be considered that and and Depend on
[0117] [Formula 7]
[0118]
[0119] It can be approximated.
[0120] Then, considering that in an X-ray diffraction apparatus, θ << 1 (according to the radian method; if expressed in degrees, considering approximately θ ≤ 10° is sufficient for practical applications. In the range θ > 10°, the slit width of the diverging slit mechanism DS reaches its maximum value, and since it is assumed that this level of control is not required, it does not need to be studied), it can be approximated as sinθ ≈ θ. and If we consider them as fixed values, then we use constants C1 and C2.
[0121] [Formula 8]
[0122]
[0123] However, it can be approximated as
[0124]
[0125] If the above results are used, the illumination width W0 is a function of θ, and can be used
[0126] [Formula 9]
[0127]
[0128] This can be approximated. Based on this relationship, if we consider an angle θ / α that is 1 / α times the angle θ, then we can derive...
[0129] [Formula 10]
[0130]
[0131] This means that its irradiation width can be approximately α times αW0.
[0132] This is about the angle θ and the divergence angle. Given the relationship, when the angle θ is 1 / α, if the divergence angle is maintained... The original angle relative to the set value of θ results in an illumination width of αW0, which is α times the original angle. Conversely, if we say the angle θ is related to the divergence angle... The relationship between them is that, relative to angle θ, the divergence angle... The value set relative to the angle αθ is then αW0, which is α times the irradiation width.
[0133] Based on the above investigation, considering θ, and Within a certain range, typically relative to angle θ, by using the divergence angle Setting the angle αθ to α times allows for precise control of the irradiation width to α times αW0 in practical applications.
[0134] In the above description, as the opening and closing mechanism, the asymmetric control unit 4 is relative to the rotation center O used to connect the X-ray source F and the goniometer 104. G The shielding member 3 on one side and the shielding member 3 on the other side are asymmetrically controlled in accordance with the rotation angle of the goniometer 104. Although a diverging slit mechanism 106 provided between the X-ray source F and the sample 110 is illustrated, the opening and closing mechanism provided with the same asymmetrical control unit 4 is not necessarily limited to the diverging slit mechanism 106. Although not shown in the specification, as an example, the asymmetrical control unit 4 can be provided on the diverging slit mechanism, which serves as an opening and closing mechanism, provided between the sample 110 and the X-ray detector 107. In this case, the diverging slit mechanism has a pair of shielding members, just like the diverging slit mechanism 106 already described, and is positioned relative to the rotation center O for connecting the X-ray detector 107 and the goniometer 104. G The straight line is asymmetrically controlled by a pair of shielding components and another shielding component on the other side, corresponding to the rotation angle of the goniometer 104.
Claims
1. An X-ray analysis device, characterized in that, have: Angle measuring instrument; The sample stage is located at the rotation center of the goniometer; An X-ray source is used to irradiate the sample fixed on the sample stage with X-rays; An X-ray detector is used to detect X-rays diffracted by the sample; as well as An opening and closing mechanism is formed between a pair of shielding members, and the width of the slit through which the X-rays pass is variable by opening and closing the shielding members. The opening and closing mechanism has an asymmetric control unit that, relative to the straight line connecting the X-ray source or X-ray detector and the center of rotation, uses shielding components on one side and the other side to asymmetrically control the opening width of the shielding components in accordance with the rotation angle of the goniometer. The pair of shielding components are supplied with a single power source and their position is controlled by a mechanical mechanism. The asymmetric control unit is a cam that rotates in conjunction with the rotation of the goniometer to control the width of the slit, and has a cam with a different shape for driving the shielding member on one side and a different shape for driving the shielding member on the other side. The cam has a central rectangular section with semicircular sections at its left and right ends, each with a diameter equal to the width of the rectangular section. The distances from the center of rotation of the cam to the center of each of the semicircular sections are different. The irradiation width of the X-rays passing through the slit, relative to the front side of the center of the sample and relative to the inside side of the center of the sample, are in fact equal to half the width of the sample.
2. The X-ray analysis apparatus according to claim 1, characterized in that, The opening and closing mechanism is a diverging slit mechanism used to shape the X-rays emitted by the X-ray source.
3. The X-ray analysis apparatus according to claim 2, characterized in that, The cam has a cylindrical surface, which makes the slit a certain width when the rotation angle of the goniometer from the X-ray source to the X-ray stage is 0 degrees or a rotation angle near that.
4. The X-ray analysis apparatus according to claim 3, characterized in that, The cam has a slit surface that keeps the width of the slit constant when the goniometer rotates to a direction where the angle of the X-rays irradiating the sample stage from the X-ray source is negative.
5. The X-ray analysis apparatus according to claim 1, characterized in that, The asymmetric control unit controls the width of the slit relative to a plurality of different α values, corresponding to a rotation angle that is α times the rotation angle of the goniometer.
6. The X-ray analysis apparatus according to claim 1, characterized in that, The asymmetric control unit has multiple α values that are different from each other, and a transmission that causes the rotational speed of the cam to rotate in a direction corresponding to a rotational angle that is α times the rotational angle of the goniometer.