JP4774007B2 - X-ray generator and X-ray analyzer - Google Patents

Description

  The present invention relates to an X-ray generation apparatus having an anti-cathode having a plurality of X-ray generation bands. The present invention also relates to an X-ray analyzer using the X-ray generator.

  In an X-ray analysis apparatus such as an X-ray diffraction apparatus, a fluorescent X-ray apparatus, or an X-ray small angle scattering apparatus, X-rays generated from an X-ray generation apparatus are irradiated on a sample to be analyzed. In a general X-ray generator, electrons generated from the cathode collide with the surface of the counter cathode, thereby generating X-rays from the surface of the counter cathode. A region where electrons collide, that is, a region where X-rays are generated is usually called an X-ray focal point.

  The wavelength of X-rays generated from the counter cathode is determined by the material of the region corresponding to the X-ray focal point in the counter cathode. Known materials for the counter cathode include Cu (copper), Mo (molybdenum), Cr (chromium), Co (cobalt), and the like. The material of the counter cathode is appropriately selected according to the type of analysis to be performed. For example, when protein structure analysis is performed by an X-ray diffractometer, a plurality of materials selected from the plurality of materials are used.

  Conventionally, two types of X-ray generation bands are provided for one counter cathode, and one of these is selectively disposed at a position facing the cathode, so that one X-ray generation device has two types of wavelengths. There is known an X-ray generator that selects and uses one of X-rays as necessary (for example, Patent Document 1). In this X-ray generator, the X-ray generation band of one of the two colors is selectively arranged at a position facing the cathode by moving the counter cathode relative to the cathode.

  Conventionally, there has been known an X-ray generator in which a plurality of X-ray generation bands are provided on one counter cathode and the cathode is moved relative to the counter cathode (for example, Patent Document 2). In this X-ray generation apparatus, only one X-ray generation band for generating X-rays is selected from a plurality by moving the electron irradiation region by moving the cathode with respect to the counter-cathode.

Microfilm (page 4, FIG. 1) of Japanese Utility Model Application No. 1-103988 (Japanese Utility Model Application Publication No. 3-43251) Japanese Unexamined Patent Publication No. 4-171700 (second page, FIG. 1)

  Generally, in an X-ray generator, the cathode and the counter cathode are arranged in a vacuum atmosphere. The reason is, for example, for preventing the occurrence of discharge, preventing the oxidation of the filament, or emitting electrons at the lowest possible cathode temperature. When the counter-cathode is placed in a vacuum state in the X-ray generator of Patent Document 1, the counter-cathode is pulled by air pressure in the direction of the vacuum region. For this reason, a very large force is required to move the counter cathode provided with the X-ray generation band of two colors against the vacuum suction force, and it is difficult to easily construct the moving device.

  In addition, in the X-ray generator disclosed in Patent Document 2, the X-ray focal point position changes when the X-ray generation band for generating X-rays is changed, so the X-ray generated from the X-ray generator is used. There has been a problem that the optical axis of an X-ray optical system, such as an X-ray diffraction optical system, must be readjusted.

  The present invention has been made in view of the above-described problems, and can change an X-ray generation zone for generating X-rays without changing the position of the X-ray focal point. An object is to provide a simple X-ray generator and X-ray analyzer.

  A first X-ray generator according to the present invention includes a cathode for generating electrons, an anti-cathode provided with two X-ray generation bands arranged opposite to each other so as to face the cathode, the cathode, A casing containing the counter cathode therein, a decompression means for decompressing the inside of the casing, an anti-cathode support means for supporting the counter cathode movably in a direction in which the X-ray generation zones are arranged, and the counter cathode And when the counter-cathode is in a first position where the X-ray generation band on the side close to the flange of the two X-ray generation bands is placed in a region where it collides with the electrons. A first abutting member that abuts the surface of the flange on the counter-cathode side, and an X-ray generation band located on the side farther from the flange of the two X-ray generation bands is placed in a region where the electrons collide. The flange when the counter-cathode is in a second position A second abutting member that abuts against the surface opposite to the counter cathode; and a flange pressure adjusting means for switching an air pressure applied to the flange between a first pressure state and a second pressure state, the first pressure The state is a force that moves the flange to the opposite side of the counter-cathode, and exerts a force on the flange that is smaller than the force by which the flange is pulled to the counter-cathode side based on the reduced pressure inside the casing. The second pressure state is a force that moves the flange to the side opposite to the counter-cathode, and the flange is pulled to the counter-cathode side based on the decompressed state inside the casing. It is a pressure state in which a force larger than the force is applied to the flange.

  In the above configuration, it is desirable that the “anti-cathode support means” is constituted by a part of the casing or a member fixed to the casing in order to make the X-ray generator small and simple. is there. However, the counter-cathode support means may be constituted by a member that is separate from the casing (that is, exists separately). In addition, the “flange” is a member that protrudes to the side from the other part, or a member that protrudes in the radial direction from the other part.

  According to the X-ray generator of the present invention configured as described above, when the flange pressure adjusting means is in the first pressure state, the flange is pulled by the vacuum suction force in the direction in which the counter cathode is present, The X-ray generation band is disposed at a position facing the cathode. On the other hand, when the flange pressure adjusting means is in the second pressure state, the force by the flange pressure adjusting means for moving the flange to the opposite side of the counter cathode overcomes the vacuum suction force that pulls the flange toward the cathode. Moves to a position where it contacts the second contact member. In this state, the X-ray generation band on the side farther than the flange is disposed at a position facing the cathode. In this way, the two X-ray generation bands can be selectively arranged at a position facing the cathode by adjusting the air pressure, and the wavelength of the generated X-ray can be changed.

  According to the present invention, since the two X-ray generation bands move and the position of the cathode does not change, the X-ray generation band that generates X-rays is changed without changing the position of the X-ray focal point. Can be made. This eliminates the need for readjustment of the optical axis of the X-ray optical system when the wavelength of X-rays generated from the X-ray generator is changed in the X-ray analyzer using the X-ray generator. In addition, according to the present invention, the drive source for moving the X-ray generation band is air pressure, and is not an electric device such as a motor. Therefore, it is not necessary to use a complicated power transmission system, and the configuration is simple. is there. Since the configuration is simple, the occurrence of failure can be suppressed.

  Next, the X-ray generator according to the present invention can further include an anti-cathode extension portion extending from the anti-cathode and having a flange attached thereto. In this case, it is desirable that the counter-cathode support means is constituted by a part of the casing, and a part of the casing supports the counter-cathode by slidingly contacting the counter-cathode extension and supporting the counter-cathode extension. .

  The anti-cathode extension has various structures as required. For example, when the counter-cathode is a rotating type counter-cathode, a main body portion in which a drive unit that rotationally drives the counter-cathode is housed may be the counter-cathode extension. Further, in the case of a fixed system in which the counter cathode is not a rotating counter cathode, any member extending from the counter cathode may become the counter cathode extending portion. According to the aspect of the present invention in which the anti-cathode extension portion is supported by a part of the casing, the X-ray generator can be made simpler and smaller than when the anti-cathode support means is configured by a dedicated member other than the casing. Can be formed.

  Next, in the above aspect of the invention in which the counter-cathode support means is constituted by a part of the casing, it is desirable that the first contact member is constituted by another part of the casing. As a result, the X-ray generator can be made even simpler and smaller.

  Next, in the X-ray generator according to the present invention, the casing has an opening for inserting the counter-cathode, and the opening is provided with a protruding member that protrudes toward the center of the opening, The second contact member is preferably constituted by the protruding member. Further, it is desirable that the inner peripheral surface of the protruding member constitutes a counter cathode support means for supporting the counter cathode. According to this configuration, the X-ray generator can be formed even more simply and compactly.

  Next, in the X-ray generator according to the present invention, when the counter-cathode is present at the second position where the X-ray generating zone on the side far from the flange is located at the position facing the cathode (that is, the pressure of the flange pressure adjusting means). When the state is in the second pressure state), it is desirable to have a fixing means for fixing the flange immovably. According to this configuration, when the pressure state of the flange pressure adjusting means is no longer the second pressure state, it is possible to prevent the flange, that is, the counter cathode from being automatically returned to the first position.

  Next, in the X-ray generator according to the present invention, the flange pressure adjusting means includes means for applying an atmospheric pressure to the surface of the flange on the counter cathode side, and a surface on the opposite side of the flange to the counter cathode. It is desirable to have first pressure switching means for switching adjacent regions between a reduced pressure state and an atmospheric pressure state. This pressure switching means can be comprised by the combination of a pressure reduction pump and a solenoid valve, for example. In the case of this aspect of the invention, the pressure switching means can also be used as a pressure reducing means for reducing the pressure around the counter cathode inside the casing. According to this configuration, the entire configuration of the X-ray generator can be formed easily and compactly, and since only one decompression means is required, the operating cost is low and maintenance is easy.

  Next, in the X-ray generator according to the present invention, the flange pressure adjusting means includes means for applying an atmospheric pressure to a surface of the flange opposite to the counter cathode, and a surface of the flange on the counter cathode side. It is desirable to have a second pressure switching means for switching the pressure to be applied between an atmospheric pressure state and a state equal to or higher than the atmospheric pressure. This configuration moves the counter cathode from the first position (the position where the first X-ray generation band faces the cathode) to the second position (the position where the second X-ray generation band faces the cathode). This is not achieved by reducing the pressure on the surface opposite to the cathode, but by applying a pressing force to the surface on the opposite cathode side of the flange.

  The movement of the counter cathode from the first position to the second position can be achieved by setting the surface of the flange opposite to the counter cathode to a reduced pressure state as in the above-described other aspects of the invention. However, in this case, the space area where the surface of the flange opposite to the counter-cathode contacts must be an airtight space. On the other hand, if the counter-cathode is moved from the first position to the second position by applying a pressing force to the surface of the flange on the counter-cathode side as in the embodiment of the present invention, the counter-cathode of the flange is provided. It is not necessary to make the space area where the surface on the opposite side contacts the airtight space, so that the structure can be simplified.

  Next, a second X-ray generator according to the present invention includes a cathode that generates electrons, an anti-cathode including a plurality of X-ray generation bands that are provided opposite to the cathode and arranged adjacent to each other, A casing in which the cathode and the counter-cathode are housed; a decompression unit that decompresses the inside of the casing; and a counter-cathode support unit that supports the counter-cathode so as to be movable in a direction in which the X-ray generation zones are arranged; A flange that moves integrally with the counter-cathode, and the counter-cathode is located at a position where an X-ray generation band that is closest to the flange among the plurality of X-ray generation bands is placed in a region that collides with the electrons. A first abutting member that abuts against the surface of the flange on the counter-cathode side, a third abutting member capable of abutting against a surface of the flange opposite to the anti-cathode, and an air pressure applied to the flange To switch between the first pressure state and the second pressure state And the first pressure state is a force that moves the flange to the opposite side of the counter-cathode, and the flange is on the counter-cathode side based on a reduced pressure state inside the casing. The second pressure state is a force that moves the flange to the opposite side of the counter-cathode, and is a reduced pressure state inside the casing. The position where the third abutting member abuts against the flange is a pressure state in which a force greater than the force with which the flange is attracted toward the cathode is applied to the flange. The X-ray generation band other than the X-ray generation band located on the side closest to the flange among the bands can be changed in accordance with each position of the flange when placed in a region where it collides with the electrons. It is characterized in.

  In the first X-ray generator described above, the counter cathode has two X-ray generation bands. On the other hand, the second X-ray generator defines a configuration in which the counter cathode has a plurality of (that is, three or more) X-ray generation bands. In the second X-ray generator, the position where the third contact member contacts the flange is not fixed to one, but can be changed at a plurality of positions corresponding to each of the plurality of X-ray generation bands. It has become. As a result, the third abutting member is the same as the first X-ray generator in that the first X-ray generating band is disposed at a position facing the cathode by the flange abutting on the first abutting member. The X-ray generation band other than the first X-ray generation band is selected from among the plurality of X-ray generation bands by appropriately changing the contact position with respect to the flange, and the X-ray generation band is opposed to the cathode. Can be arranged.

  According to the second X-ray generator, since a plurality of X-ray generation bands move with respect to the cathode and there is no change in the position of the cathode, the X-ray focal point is not changed. The X-ray generation band for generating a line can be changed between three or more X-ray generation bands. This eliminates the need for readjustment of the optical axis of the X-ray optical system when the wavelength of X-rays generated from the X-ray generator is changed in the X-ray analyzer using the X-ray generator. In addition, according to the present invention, the drive source for moving the X-ray generation band is air pressure, and is not an electric device such as a motor. Therefore, it is not necessary to use a complicated power transmission system, and the configuration is simple. is there.

  Next, a third X-ray generator according to the present invention includes a cathode for generating electrons, an anti-cathode having two X-ray generation bands provided opposite to the cathode and arranged adjacent to each other, A casing in which the cathode and the counter-cathode are housed; a decompression unit that depressurizes the interior of the casing; a counter-cathode rotation driving unit that rotates the counter-cathode around an axis passing through the counter-cathode; and the counter-cathode An anti-cathode housing which accommodates the rotation driving means and extends from the anti-cathode; a flange which is provided on an outer peripheral surface of the anti-cathode housing and projects in a radial direction of the anti-cathode housing; and the anti-cathode housing Counter-cathode support means for movably supporting the counter-cathode housing in the axial direction, a first abutting member for stopping the flange from moving toward the counter-cathode, and a flange on the opposite side of the counter-cathode. A second abutting member for stopping movement; and a flange pressure adjusting means for switching an air pressure applied to the flange between a first pressure state and a second pressure state. A force that moves to the opposite side of the cathode, and is a pressure state that applies a force to the flange that is smaller than a force that the flange pulls to the counter-cathode side based on a reduced pressure state inside the casing; The two-pressure state is a force that moves the flange to the side opposite to the counter-cathode, and is a force that is greater than the force that pulls the flange in the direction in which the counter-cathode is present based on the reduced pressure state inside the casing. Is applied to the flange, and the first abutting member is placed in a region where the X-ray generation band on the side closer to the flange of the two X-ray generation bands collides with the electrons. When the counter-cathode is in the first position, it abuts against the surface on the counter-cathode side of the flange, and the second abutment member is located on the far side from the flange of the two X-ray generation bands. When the counter-cathode is in a second position where the line-generating band collides with the electrons, the flange contacts the surface of the flange opposite to the counter-cathode.

  The first X-ray generator described above is an invention in which the counter cathode has two X-ray generation bands, and does not particularly define whether the counter cathode is a rotating type or a fixed type. . On the other hand, in the third X-ray generator, the counter-cathode is a rotating counter-cathode, the counter-cathode rotation driving means is accommodated in the counter-cathode housing, and a flange is formed on the outer peripheral surface of the counter-cathode housing, A configuration in which two X-ray generation bands are provided on the counter cathode is defined.

  According to the third X-ray generator, since the two X-ray generation bands move with respect to the cathode and the position of the cathode does not change, the X-ray focal point is not changed. The X-ray generation zone for generating a line can be changed. Therefore, in the X-ray analyzer using the third X-ray generator, it is necessary to readjust the optical axis of the X-ray optical system when the wavelength of the X-ray generated from the X-ray generator is changed. Disappears. In addition, according to the present invention, the drive source for moving the X-ray generation band is air pressure, and is not an electric device such as a motor. Therefore, it is not necessary to use a complicated power transmission system, and the configuration is simple. is there.

  Next, an X-ray analyzer according to the present invention is characterized by having the X-ray generator configured as described above and an X-ray optical system using X-rays generated from the X-ray generator. As such an X-ray analysis apparatus, an X-ray diffraction apparatus, a fluorescent X-ray apparatus, an X-ray small angle scattering apparatus, and the like are conceivable. According to the X-ray analysis apparatus of the present invention, the X-ray generation zone that generates X-rays can be changed without changing the position of the X-ray focal point in the X-ray generation apparatus. Even when the wavelength of the X-ray to be changed is changed, it is not necessary to readjust the optical axis of the X-ray optical system in the X-ray analyzer. In addition, in the X-ray generator used in the X-ray analyzer according to the present invention, the driving source for moving the X-ray generating zone is air pressure, not an electric device such as a motor. The configuration is simple because there is no need to use.

According to the X-ray generation apparatus and the X-ray analysis apparatus of the present invention, the X-ray focal point is configured so that two or more X-ray generation bands move with respect to the cathode and the position of the cathode does not change. The X-ray generation band for generating X-rays can be changed without changing the position of the X-ray. For this reason, in the X-ray analyzer using this X-ray generator, it is not necessary to readjust the optical axis of the X-ray optical system when the wavelength of the X-ray generated from the X-ray generator is changed. .
In addition, according to the X-ray generator and the X-ray analyzer according to the present invention, the driving source for moving the X-ray generating zone is air pressure, not an electric device such as a motor. The configuration is simple because there is no need to use. Since the configuration is simple, the occurrence of failure can be suppressed.
Further, since the driving source for moving the X-ray generation band is air pressure, a decompression device for setting the inside of the casing containing the cathode and the counter cathode to a vacuum state is for moving the X-ray generation band. It can also be used as a drive source, and the configuration can be simplified.

(Embodiment of X-ray analyzer and first embodiment of X-ray generator)
Hereinafter, an X-ray analyzer and an X-ray generator according to the present invention will be described based on embodiments. Of course, the present invention is not limited to this embodiment. In the following description, the drawings are referred to. In the drawings, the components may be shown in different ratios from the actual ones in order to show the characteristic parts in an easy-to-understand manner.

  FIG. 1 shows a planar structure of an X-ray diffraction apparatus 1 which is an embodiment of an X-ray analyzer according to the present invention. The in-plane direction of the drawing is the horizontal direction, and the vertical direction to the drawing is the vertical direction. The X-ray diffractometer 1 includes an X-ray generator 2A and a goniometer 3. The goniometer 3 includes a θ rotation table 4, a 2θ rotation table 5, and a detector arm 6 extending from the 2θ rotation table 5. The θ turntable 4 can rotate around its own central axis ω (extending in the direction perpendicular to the paper surface). The 2θ turntable 5 can also rotate around the same axis ω. A diverging slit 7 is provided between the X-ray generator 2 </ b> A and the goniometer 3. The divergence slit 7 is a slit that regulates the divergence of X-rays emitted from the X-ray generator 2 </ b> A and irradiates the sample S with it.

  A sample holder 10 is detachably mounted on the θ turntable 4, and a sample S to be measured is accommodated in the sample holder 10. For example, the sample S is packed in a recess provided in the sample holder 10 or in a through opening. On the detector arm 6, a scattering slit 11, a light receiving slit 12, and an X-ray counter 13 as an X-ray detection means are provided. The scattering slit 11 is a slit that prevents scattered rays unnecessary for analysis from entering the X-ray counter 13. The light receiving slit 12 is a slit that passes secondary X-rays emitted from the sample S, such as diffraction lines, and blocks other unnecessary X-rays. The X-ray counter 13 is configured by a zero-dimensional counter that is a counter having no position resolution, for example, an SC (Scintillation Counter).

  The X-ray generator 2A is fixedly arranged at a fixed position. The X-ray generator 2 </ b> A includes a filament 16 that is a cathode that emits thermoelectrons when energized, and a target 17 </ b> A as an anti-cathode disposed to face the filament 16. The electrons emitted from the filament 16 collide with the target 17A at high speed. The region where the electrons collide is the X-ray focal point F, and X-rays are generated from the X-ray focal point F. The planar shape of the X-ray focal point F is, for example, 1 mm × 10 mm. The X-ray R1 generated from the target 17A is incident on the sample S with the divergence angle regulated by the divergence slit 7.

  The θ turntable 4 is driven by the θ rotation driving device 20 and rotates around the ω axis. This rotation may be intermittent rotation at every predetermined step angle or may be continuous rotation at a predetermined angular velocity. This rotation of the θ turntable 4 is a rotation for changing the incident angle θ of the X-ray R1 to the sample S, and is generally called θ rotation.

  The 2θ turntable 5 is driven by the 2θ rotation drive device 21 and rotates around the ω axis. This rotation is generally called 2θ rotation, and is intermittent rotation or continuous rotation performed in the same direction as the above θ rotation at a double angular velocity. This 2θ rotation is performed when X-rays are incident on the sample S at an incident angle θ, and when secondary X-rays (for example, diffraction lines) R2 are generated from the sample S, the secondary X-rays R2 are converted by the X-ray counter 13. This is a rotation for receiving light.

  The θ rotation driving device 20 and the 2θ rotation driving device 21 are constituted by arbitrary rotation driving devices. Such a rotational drive device is constituted by, for example, a rotational power source and a power transmission device. The rotational power source is constituted by, for example, a motor capable of controlling the rotation angle, such as a servo motor or a stepping motor. The power transmission device includes, for example, a worm fixed to the output shaft of the rotational power source and a worm wheel that meshes with the worm and is fixed to the central axis of the θ rotary table 4 and the central axis of the 2θ rotary table 5. The

  When the θ-rotation table 4 and the sample S mounted thereon rotate θ, and the 2θ-rotation table 4 and the X-ray counter 13 supported thereon rotate 2θ, the X-ray focal point F is on the goniometer circle Cg centered on the axis ω. The X-ray condensing point of the light receiving slit 12 moves on the goniometer circle Cg. Further, during the θ rotation of the sample S and the 2θ rotation of the X-ray counter 13, the X-ray focal point F, the ω-axis line, and the X-ray condensing point of the light receiving slit 12 exist on the concentrated circle Cf. The goniometer circle Cg is a virtual circle with a constant radius, and the concentrated circle Cf is a virtual circle whose radius changes according to changes in the θ angle and the 2θ angle.

Hereinafter, the operation of the X-ray diffraction apparatus 1 having the above configuration will be described.
First, as necessary, various X-ray light forehead elements existing on the X-ray optical path from the X-ray focal point F to the X-ray counter 13 are accurately aligned on the X-ray optical axis. That is, optical axis adjustment is performed. Next, the X-ray incident angle θ with respect to the sample S and the diffraction angle 2θ of the X-ray counter 13 are set to desired initial positions (zero positions).

  Next, the filament 16 is heated by energization, and thermoelectrons are generated from the filament 16. The electrons are normally restricted in the traveling direction by an electric field applied by Wehnelt (not shown) and then collide with the surface of the target 17A at a high speed to form an X-ray focal point F. Then, X-rays having a wavelength corresponding to the material of the target 17A are emitted from the X-ray focal point F. The current flowing through the filament 16 by energization of the filament 16 is generally called tube current. Further, in order to accelerate the electrons emitted from the filament 16 and colliding with the target 17A, a voltage having a predetermined magnitude is applied between the filament 16 and the target 17A. This voltage is generally called a tube voltage. In the present embodiment, the tube voltage and the tube current are set to 40 to 60 kV and 50 to 300 mA, respectively. The target material will be described later.

  The X-ray R1 emitted from the X-ray generator 2A and diverges includes continuous X-rays including X-rays having various wavelengths and characteristic X-rays having specific wavelengths. In order to select a desired characteristic X-ray from these X-rays, an incident-side monochromator (so-called incident monochromator) is provided on the X-ray optical path from the X-ray generator 2A to the sample S. The X-ray R1 is irradiated on the sample S with its divergence restricted by the divergence slit 7. While the sample S rotates by θ and the X-ray counter 13 rotates by 2θ, the X-ray R1 incident on the sample S satisfies the predetermined diffraction condition, that is, the Bragg diffraction angle with respect to the crystal lattice plane in the sample S. Then, a second-order diffraction line, for example, a diffraction line R2 is generated from the sample S at a diffraction angle 2θ. The diffraction line R2 passes through the scattering slit 11 and the light receiving slit 12, and is received by the X-ray counter 13. The X-ray counter 13 outputs an electrical signal corresponding to the number of X-rays received, and the X-ray intensity is calculated based on this output signal.

  The above X-ray intensity calculation processing is performed for each of the incident X-ray angle θ and the diffraction angle 2θ, and as a result, the X-ray intensity I (2θ) at each angular position of the diffraction angle 2θ is obtained. If the X-ray intensity I (2θ) is plotted on the plane coordinates with the diffraction angle 2θ on the horizontal axis and the X-ray intensity I on the vertical axis, a known diffraction line figure can be obtained. Then, the internal structure of the sample S can be analyzed by observing the generation angle (2θ) and the generation intensity (I) of the X-ray intensity peak waveform that appears on the diffraction line pattern.

Hereinafter, the X-ray generator 2A will be described in detail.
FIG. 2 shows the X-ray generator 2A in detail. The X-ray generator 2A includes the filament 16 described above, the target 17A described above, a target unit 24 including the target 17A, and a casing 25. The filament 16 and the target 17A are accommodated in the internal space of the casing 25. The internal space of the casing 25 is generally a cylindrical space centered on the axis X0 when viewed from the direction of the arrow B. The target unit 24 has an anti-cathode housing 26 as an anti-cathode extension extending from the target 17A. The anti-cathode housing 26 supports the target 17A so as to be rotatable as indicated by an arrow A about the axis X0. The rotation speed of the target 17A is, for example, 6,000 rpm. The casing 25 and the counter cathode housing 26 are made of, for example, copper or a copper alloy. The counter cathode housing 26 is formed in a cylindrical shape when viewed from the direction of arrow B. The casing 25 is formed in a cylindrical shape or a rectangular tube shape when viewed from the arrow B direction.

  The target 17A is provided with two types of X-ray generating bands 27A and 27B juxtaposed on the outer peripheral surface of a base member formed in a laterally cup-like shape in the drawing with a material having high thermal conductivity (for example, Cu (copper)). It is formed by. The X-ray generation bands 27A and 27B are provided in a ring shape (that is, in an annular shape) and in a band shape in the direction in which the central axis line X0 of the target 17A extends (ie, in the axial direction). The X-ray generation bands 27A and 27B are formed of different materials, and each is formed of one material selected from, for example, Cu, Mo (molybdenum), Cr (chromium), and Co (cobalt). Yes. Each material of Mo, Cr, and Co is formed on the Cu base member by, for example, ion plating, plating, shrink fitting, and other appropriate film forming methods. If the size of the X-ray focal point F is 1 mm × 10 mm, the width in the axial direction of each X-ray generation band 27A, 27B is set to about 13 mm.

  As shown in FIG. 3, the anti-cathode housing 26 is generally formed in a cylindrical shape centering on the axis X0, and a thin cylindrical first inner tube 30 is provided at the center of the inside, and the first inner tube is provided. A second inner tube 31 is provided coaxially on the outside of 30. The first inner tube 30 is provided so as not to rotate (that is, fixed) with respect to the outer wall of the anti-cathode housing 26, and the second inner tube 31 is provided so as to be rotatable with respect to the outer wall of the anti-cathode housing 26. A gap for passing water is formed between the first inner pipe 30 and the second inner pipe 31. The second inner pipe 31 constitutes the bottom 32 of the target 17A, and the first inner pipe 30 constitutes a partition member 33 inside the target 17A.

  A disc-shaped flange 35 protruding in the radial direction is provided on the outer wall of the counter-cathode housing 26. Adjacent to the target 17 </ b> A side of the flange 35, a disk-shaped inner sliding portion 36 having a smaller diameter than the flange 35 is provided. An outer peripheral surface of the inner sliding portion 36 is a sliding surface 36a. O (o) rings 37a and 37b, which are sealing materials for airtightness, are provided at the tips of the flange 35 and the inner sliding portion 36, respectively. An O-ring 37c is also provided at an appropriate position on the outer wall of the anti-cathode housing 26 on the side opposite to the target 17A with respect to the flange 35.

  In the space between the side wall of the anti-cathode housing 26 and the second inner tube 31, the magnetic seal device 38, the bearing 39, the direct drive mechanism 40, the bearing 41, and the sealing material 42 for preventing water leakage are sequentially formed from the target 17 </ b> A side. Is provided. The magnetic seal device 38 is a shaft seal device provided on the second inner tube 31 that is a rotation shaft, and the pressure difference between one region and the other region along the rotation shaft with the magnetic seal device 38 as a boundary. It is a well-known sealing device for maintaining and maintaining one of those areas in a clean atmosphere. This magnetic seal device normally forms a magnetic fluid film between a rotating shaft and a pole piece by a magnetic force by forming a magnetic closed circuit between the rotating shaft and a pole piece facing the rotating shaft. The pressure difference is maintained by the membrane.

  The second inner pipe 31 is supported by a pair of bearings 39 and 41 so as to be rotatable about the axis X0. The direct drive mechanism 40 includes a rotor 44 made of a magnetically permeable member provided on the outer peripheral surface of the second inner tube 31, and a stator coil fixed to the inner surface of the side wall of the counter-cathode housing 26 and disposed around the rotor 44. 45. A rotating magnetic field is formed in the stator coil 45 by energizing the stator coil 45 with a motor drive current by a motor drive control circuit (not shown). By generating a rotational driving force in the rotor 44 by this formed rotating magnetic field, the second inner tube 31 is rotated about the axis X0.

  When the second inner pipe 31 is axially rotated, the target 17A integrated therewith rotates axially. The target 17A is cooled by this rotation of the target 17A. On the other hand, water is supplied to a water supply port 46 provided at the rear end (left end in the figure) of the counter cathode housing 26. This water flows in the cylindrical space between the first inner pipe 30 and the second inner pipe 31, flows into the target 17A, and proceeds along the partition member 33 to cool the target 17A from the inside. . Thereafter, the water is collected inside the first inner pipe 30, further flows inside the first inner pipe 30, and is discharged outside through the drain port 47 at the left end portion of the counter-cathode housing 26. The target 17A is cooled by both rotating the target 17A about the axis X0 and flowing the cooling water on the inner surface of the target 17A. The thermoelectrons are rapidly transferred to the X-ray generation band 27A or the X-ray generation band 27B. This is to protect the target 17A by preventing the target 17A from being heated to a temperature higher than the allowable limit when it is caused to collide.

  In FIG. 2, the central portion of the left end surface of the casing 25 is an opening, for example, a circular opening as viewed in the direction B, and the tip of the target unit 24 is inserted into the casing 25 through the opening. Inside the casing 25, a casing flange 49, which is a portion protruding toward the center (that is, the axis X0), is provided. An end portion (left end portion in the figure) of the casing flange 49 is a stepped portion. The internal space of the casing 25 on the opening side of the stepped portion of the casing flange 49 is a disk-shaped or cylindrical space as viewed in the direction of the arrow B. The diameter of this space is slightly larger than the flange 35 of the target unit 24, and the outer peripheral surface of the target flange 35 is slidable with respect to the inner peripheral surface of the opening portion of the casing 25 (that is, slidable). Or sliding movement). A space between the target flange 35 and the casing 25 is airtightly held by an O-ring 37 a attached to the outer periphery of the target flange 35.

  The internal space formed by the casing flange 49 is a cylindrical space as viewed in the direction B, except for the space in which the filament 16 is accommodated. The inner peripheral surface of the casing flange 49 has a diameter slightly larger than the diameter of the inner sliding portion 36 of the target unit 24, and the inner sliding portion 36 can slide with respect to the casing flange 49. A space between the inner sliding portion 36 and the casing flange 49 is hermetically maintained by an O-ring 37 b attached to the outer periphery of the inner sliding portion 36. A space extending in the radial direction is provided in a part of the casing flange 49 (lower part in the figure), and the filament 16 is accommodated in the space.

  A ring-shaped (that is, annular) protruding member 50 is provided at the left end opening of the casing 25 as viewed in the direction of the arrow B. The protruding member 50 protrudes in the radial direction toward the center of the opening (that is, the axis X0) at the left end opening of the casing 25. The protruding member 50 is provided by fixing the ring member to the left end surface of the casing 25 with screws or other fixing means. The protruding member 50 and the casing 25 are hermetically sealed by an O-ring 51.

  A screw 52 is screwed into an appropriate position of the protruding member 50 (a lower portion of the protruding member 50 in FIG. 2). A female screw 53 is provided on the flange 35 corresponding to the screw 52. The periphery of the screw 52 is hermetically sealed by an O-ring 63 that is a sealing material. The screw 52 and the female screw 53 cooperate to constitute a fixing means for fixing the flange 35 in a fixed position.

  The inner wall portion at the front end of the casing flange 49 is in sliding contact with a sliding surface 36 a that is the outer peripheral surface of the inner sliding portion 36 of the counter-cathode housing 26. Further, the inner peripheral surface of the protruding member 50 is in sliding contact with the outer peripheral surface of the outer sliding portion 43 of the counter cathode housing 26. Here, the slidable contact means contact in a slidable state or contact in a slidable state. With the above sliding contact structure, the target unit 24 is supported by both the casing flange 49 and the protruding member 50 so as to be movable in the axial direction. The casing flange 49 and the counter-cathode housing 26 are hermetically sealed by an O-ring 37b. The protruding member 50 and the counter-cathode housing 26 are hermetically sealed by an O-ring 37c.

  The step portion at the tip of the casing flange 49 constitutes a first abutting member with which the surface of the target flange 35 on the target 17A side abuts. The casing-side wall surface of the projecting member 50 constitutes a second abutting member with which the surface of the target flange 35 on the side opposite to the target 17A abuts.

  Since the casing flange 49 and the inner sliding portion 36 of the counter-cathode housing 26 are in airtight sliding contact, the internal space of the casing 25 in which the target 17A and the filament 16 are accommodated is kept airtight. An X-ray window 28 for extracting X-rays generated from the target 17A to the outside is provided in a part of the casing 25 on the side of the target 17A. The X-ray window 28 has a mechanical strength sufficient to maintain a pressure difference between a vacuum state and an atmospheric pressure state, and is formed of a material that can pass X-rays, for example, Be (beryllium). . Usually, the extraction angle α of X-rays extracted from the X-ray window 28 is α = 6 °.

  In the present embodiment, anti-cathode support means for supporting the target 17A so as to be movable in the direction in which the axis X0 extends is constituted by both the casing flange 49 and the protruding member 50. However, either one of the casing flange 49 and the protruding member 50 is provided by disposing either the inner peripheral surface of the casing flange 49 or the inner peripheral surface of the protruding member 50 in the radial direction away from the outer peripheral surface of the counter-cathode housing 26. Alternatively, the target unit 24 may be supported so as to be movable in parallel.

  The target unit 24 includes a first position where the right side surface of the target flange 35 (that is, the surface on the target 17A side) abuts on the tip step portion of the casing flange 49, and the left side surface of the target flange 35 (that is, the surface opposite to the target 17A). ) Can be translated in the direction along the axis line X0 between the second position where the projection member 50 abuts against the right side surface of the projecting member 50 (ie, the surface on the target 17A side). FIG. 2 shows a state where the target unit 24 is in the first position. FIG. 4 shows a state in which the target unit 24 is in the second position. When the target unit 24 is in the first position shown in FIG. 2, the filament 16 forms an X-ray focal point F on the first X-ray generation band 27A. On the other hand, when the target unit 24 is in the second position shown in FIG. 4, the filament 16 forms an X-ray focal point F on the second X-ray generation band 27B.

In FIG. 2, a pipe 54 is provided in communication with the internal space of the casing 25. A turbo molecular pump 55 and a rotary pump 56 are provided on the pipe 54. The rotary pump 56 is a decompression pump that roughly decompresses the inside of the casing 25 to a relatively high atmospheric pressure. The turbo molecular pump 55 is a decompression pump that decompresses the atmosphere decompressed to some extent by the rotary pump 56 toward a state close to a vacuum state. By the action of the turbo molecular pump 55, the surroundings of the target 17A and the filament 16 can be decompressed with high accuracy to 10 ⁻³ Pa or less, which is a substantially vacuum state. As long as the inside of the casing 25 can be reduced to a substantially vacuum state, a combination of a high vacuum pump other than the turbo molecular pump and an auxiliary pump other than the rotary pump 56 may be used.

  A vent hole 57 is provided in the wall of the casing 25 where the casing flange 49 is provided. The vent hole 57 is a hole having a circular cross section in the present embodiment, but the vent hole 57 can be an opening having any shape as long as it communicates with the atmosphere. One end portion of the vent hole 57 opens to a contact portion (that is, a step portion) of the casing flange 49 with the target flange 35, and the other end portion opens to the outer peripheral surface of the casing 25 to communicate with the atmospheric pressure. .

  A pressure switching device 58 is attached to a ring-shaped projecting member 50 fixed to the left end surface of the casing 25. The pressure switching device 58 is connected to a pipe 59 connected to an appropriate position of the protruding member 50, a three-port solenoid valve 60 having one port connected to the pipe 59, and another one port of the three-port solenoid valve 60. And a connected rotary pump 61. The remaining one port of the three-port solenoid valve 60 communicates with atmospheric pressure.

  The operation of each element of the electromagnetic valve 60, the turbo molecular pump 55, and the rotary pumps 56 and 61 is controlled by the control device 62A. The control device 62A may be configured by a computer that controls the entire X-ray diffraction device 1 of FIG. 1, may be configured by an independent computer different from the computer, or an appropriate sequence not including the computer. It may be a circuit.

  When X-rays are generated from the target 17A in the X-ray generator 2A, the inside of the casing 25 around the target 17A is decompressed to a substantially vacuum state by the rotary pump 56 and the turbo molecular pump 55. Under this vacuum state, the entire target unit 24 is pulled in the direction of the target 17A (right direction in the figure) by the vacuum suction force.

  The electromagnetic valve 60 in the pressure switching device 58 connects the pipe 59 to atmospheric pressure when the input voltage is in an OFF state, for example. At this time, the force for pulling the flange 35 of the target unit 24 to the side opposite to the target 17A does not act. Therefore, the force for pulling the flange 35 of the target unit 24 to the side opposite to the target 17A is It will be less than the force that is pulled to. As a result, the flange 35 is pulled by the vacuum suction force and moves in the direction of the target 17A, and is stationary with the right side surface of the flange 35 in contact with the stepped portion of the casing flange 49 as the first contact member. .

  The positions of the target unit 24 and the flange 35 in this state are referred to as a first position. When the flange 35 is in the first position, the first X-ray generation band 27A on the flange 35 side on the target 17A is in a position facing the filament 16. Therefore, when electrons are emitted from the filament 16, X-rays are generated from the X-ray generation band 27A, and the X-rays are taken out from the X-ray window 28 to the outside. If the X-ray generation band 27A is made of Cu, X-rays having a wavelength corresponding to Cu are generated from the X-ray generator 2A.

  The solenoid valve 60 connects the pipe 59 to the rotary pump 61 when the input voltage is in an ON state, for example. Thereby, the pressure in the space area on the left side of the flange 35 is reduced by the rotary pump 61. At this time, the air suction force that attempts to move the flange 35 to the side opposite to the target 17 </ b> A changes according to the area of the flange 35. In the present embodiment, the area of the flange 35 is set so that the force for moving the flange 35 to the side opposite to the target 17A is larger than the force for pulling the flange 35 toward the target 17A by the vacuum suction force. Yes. Accordingly, when the electromagnetic valve 60 is turned on and the left side of the flange 35 is decompressed by the rotary pump 61, the force pulling the entire target unit 24 in the left direction becomes larger than the force pulling in the right direction, and the target unit 24 4 moves to the left, and as shown in FIG. 4, the left side surface of the flange 35 comes into contact with the protruding member 50 as the second contact member and comes to rest.

  The position of the target unit 24 and the flange 35 in this state is referred to as a second position. When the flange 35 is in the second position, the X-ray generation band 27B far from the flange 35 on the target 17A is in a position facing the filament 16. Therefore, when electrons are emitted from the filament 16, X-rays are generated from the X-ray generation band 27B, and the X-rays are taken out from the X-ray window 28 to the outside. If the X-ray generation band 27B is made of Mo, X-rays having a wavelength corresponding to Mo are generated from the X-ray generator 2A.

  As described above, when the pressure switching device 58 is turned off in FIG. 2, X-rays having a wavelength corresponding to the first X-ray generation band 27A can be generated from the X-ray generation device 2A, and on the other hand, the pressure switching device 58 Is turned on (see FIG. 4), X-rays having a wavelength corresponding to the second X-ray generation band 27B can be generated from the X-ray generator 2A. Even when the type of X-rays to be generated is switched in this way, the position of the filament 16 does not change, so that no positional change also occurs in the X-ray focal point F. Therefore, even when the type of X-rays generated from the X-ray generator 2A in FIG. 1 is changed, the position of the X-ray focal point F in the X-ray optical system does not change, and accordingly, the diverging slit 7 and the goniometer 3 are not changed. This is very advantageous because it is not necessary to readjust the position of each element in the X-ray optical system.

  When the pressure switching device 58 is turned on and the target 17A is disposed at the second position shown in FIG. 4, it is necessary to keep the pressure switching device 58 in the on state in order to maintain the second position. May be consumed in vain. In order to solve this problem, after the target 17A and the flange 35 are arranged at the second position, the flange 35 can be fixed to the right side surface of the protruding member 50 by tightening the fixing screw 52 to the casing 25 side. desirable. In this way, even if the pressure switching device 58 is switched to the OFF state, the target 17A can be continuously disposed at the second position, and the cost can be reduced. The fixing method is not limited to the fixing method using screws, and an appropriate method can be adopted as necessary.

  Furthermore, in this embodiment, since the target unit 24 is moved between the first position (FIG. 2) and the second position (FIG. 4) based on the air pressure, an electric device such as a motor is used as a power source. Compared with the case where a more complicated power transmission system is used, the structure for the movement is simple, and it is stable and does not cause a failure.

The area of the target flange 35 required to overcome the vacuum state in the target chamber over the entire target unit 24 and move from the first position (FIG. 2) to the second position (FIG. 4), particularly the target 17A of the target flange 35. The area of the surface opposite to the surface that receives the pressure by the pressure switching device 58 ignores the frictional resistance caused by the sliding of the O-rings 37a, 37b, and 37c when the diameter of the inner sliding portion 36 is 100 mm. Then, it is 7,850 mm ² or more in a state where the pressure is reduced by the rotary pump 61. This area is preferably 8,000 mm ² or more, more preferably 10,000 mm ² or more when the pressure reduced by the rotary pump 61 is 1,000 Pa or less.

  Hereinafter, the driving force by the air pressure when the target unit 24 is moved to the first position (FIG. 2) and the second position (FIG. 4) will be described with reference to FIG. FIGS. 5A and 5B show the aerodynamic relationship when the target unit 24 is in the second position (see FIG. 4) and the first position (see FIG. 2), respectively.

  First, in the state of the second position shown in FIG. 5A (position moved to the opposite side of the vacuum region), the force F1 indicates a force drawn by the vacuum on the target side, and the force F2 is drawn by the outside pressure reduction. Showing power. The force F2 is shown as a total force acting on the entire ring-shaped target flange 35, and the parenthesized force F2 is shown as a reference for easy understanding.

Force F1 entire target unit 24 is pulled to a target 17A side, when the diameter of the inner slide portion 36 and the _{d 1,} proportional to the area π _(d ^1/2) 2 of the whole. On the other hand, the force F2 that the whole of the target unit 24 is pulled by the outer vacuum to the outside of the casing 25 (the left side in the figure), the diameter d ₃ of the outer sliding portion of diameter d ₂ and anticathode housing 26 of the target flange 35 Are closely related, specifically,
^{_{π (d 2/2) 2}} -π (d 3/2) 2
Is proportional to That is, in order to hold the second position in FIG.
^{_{π (d 2/2) 2}} -π (d 3/2) 2> π (d 1/2) 2
It is necessary to satisfy the relational expression.

Next, in the state of the first position (position moved to the vacuum region side) shown in FIG. 5B, only the force F1 drawn to the target 17A side is related to the entire target unit 24. Since the other part is the atmosphere (1 atm), the force F2 is not generated. When the diameter of the inner bearing part 36 and d1, force F1 pulls the target unit 24 to the vacuum side is proportional to the total area π _(d ^1/2) 2 of the inner sliding portion 36. Since there is no force pulling the target unit 24 other than the force F1, the target unit 24 is held in the first position.

When the outer diameter _{d 1} of the inner sliding portion 36 of the target unit 24 is 100 mm, the diameter _{d 3} of the outer sliding portion 43 of the anticathode housing 26 is 80 mm,
^{_{π (d 2/2) 2}} -π (d 3/2) 2> π (d 1/2) 2
The diameter _{d 2} of the target flange 35 that satisfies is not less than 128.1Mm, the O-ring 37a, 37b, considering the frictional resistance during 37c sliding of the outer of the inner sliding portion 36 of the target unit 24 When the diameter is 100 mm and the outer sliding portion 43 has a diameter of 80 mm, the outer diameter of the target flange 35 is desirably 140 mm or more.

(Modification)
FIG. 6 shows a modification of the first embodiment described above. In the X-ray generator 2B according to this modification, the same reference numerals as those in FIG. 2 denote the same members, and the description of those members will be omitted. The X-ray generator 2B is different from the X-ray generator 2A in FIG. 2 in that the rotary pump 61 constituting the pressure switching device 58 in FIG. 2 is removed and the inside of the casing 25 is decompressed instead. That is, the pressure switching device 58 is configured by using the rotary pump 56 as well. The control device 62C controls each operation of the three-port solenoid valve 60, the turbo molecular pump 55, and the rotary pump 56.

  FIG. 9 shows another modification. In the X-ray generator 2E according to this modification, the same reference numerals as those in FIG. 2 indicate the same members, and the description of those members will be omitted. The X-ray generator 2E is different from the X-ray generator 2A in FIG. 2 in that the shape of the casing flange 49 is modified. Specifically, in the embodiment shown in FIG. 2, the casing flange 49 is provided in a shelf shape on the entire inner surface of the casing 25, but in the present embodiment shown in FIG. 9, the casing flange 49 is the target flange 35. And a target 17A as a partial ring-shaped protrusion. According to this embodiment, a larger space than the case of FIG. 2 is formed around the target 17 </ b> A inside the casing 25.

(Second embodiment of X-ray generator)
FIG. 7 shows a second embodiment of the X-ray generator according to the present invention. In FIG. 7, the same reference numerals as those in FIG. 2 denote the same members, and description of those members is omitted. In the X-ray generator 2C according to the present embodiment, the tip inner wall portion of the casing flange 49 and the axial center side inner wall portion of the projecting member 70 serve as an anti-cathode support means that supports the target unit 24 so that it can be translated in the direction of the axis X0. Works. The stepped portion of the casing flange 49 acts as a first contact member that contacts the surface of the flange 35 on the target 17A side. The target-side inner wall portion of the protruding member 70 acts as a second contact member that contacts the surface of the flange 35 opposite to the target 17A.

  In the X-ray generator 2A according to the first embodiment shown in FIG. 2, a vent hole 57 is provided on the surface of the flange 35 of the target unit 24 on the target 17A side, and the flange 35 is on the opposite side of the target 17A. A pressure switching device 58 was provided for the surface. The space region in contact with the surface of the flange 35 opposite to the target 17 </ b> A was made an airtight space by the ring-shaped projecting member 50 fixed to the left end surface of the casing 25.

  On the other hand, in the second X-ray generator 2C shown in FIG. 7, the pressure switching device 65 is provided in the atmosphere side opening of the vent hole 57 provided to the surface of the target flange 35 on the target 17A side. Yes. The protruding member 70 functioning as the counter-cathode support means and the second contact member is fixed to the left end surface of the casing 25, but has a configuration different from the ring-shaped protruding member 50 shown in FIG. . The projecting member 70 may be ring-shaped (annular) when viewed from the direction of arrow B, or a plurality of block-shaped projecting members 70 are provided intermittently at appropriate angular intervals when viewed from the direction of arrow B. Also good. In the present embodiment, it is assumed that the four projecting members 70 are provided at equal intervals of 90 ° when viewed from the direction of arrow B.

  In FIG. 2, the space area between the target flange 35 and the protruding member 50 is kept airtight. On the other hand, in the present embodiment shown in FIG. 7, since the block-like projecting member 70 is fixed to the left end surface of the casing 25 with a space therebetween, the space region between the target flange 35 and the projecting member 70 is airtight. Instead, it leads to the atmosphere. Further, no sealing material such as an O-ring is provided between the protruding member 70 and the casing 25 and between the protruding member 70 and the counter-cathode housing 26.

  The pressure switching device 65 has a three-port solenoid valve 60, and a vent hole 57 is connected to one port of the solenoid valve 60. The pressurizing pump 66 is connected to the other one port of the electromagnetic valve 60, and the remaining one port of the electromagnetic valve 60 is connected to the atmosphere. Each operation of the electromagnetic valve 60, the pressurizing pump 66, the turbo molecular pump 55, and the rotary pump 56 is controlled by the control device 62B. The control device 62B may be configured by a computer that controls the entire X-ray diffraction device 1 of FIG. 1, may be configured by an independent computer different from the computer, or an appropriate sequence not including the computer. It may be a circuit.

  Also in this embodiment, the internal space of the casing 25 provided with the target 17A and the filament 16 is set to a highly accurate vacuum state by the rotary pump 56 and the turbo molecular pump 55. The pressure switching device 65 selectively selects two pressure states: a first pressure state in which the vent hole 57 communicates with the atmosphere by the electromagnetic valve 60 and a second pressure state in which the vent hole 57 communicates with the pressurization pump 66 by the electromagnetic valve 60. Realize. FIG. 7 shows a first pressure state in which the vent hole 57 communicates with the atmosphere. In this first pressure state, atmospheric pressure is applied to both the surface of the flange 35 on the target 17A side and the opposite surface. The target unit 24 is sucked by the vacuum state inside the target 25 and is stationary with the surface of the flange 35 on the target 17A side in contact with the stepped portion of the casing flange 49 that is the first contact member. . In this state, the first X-ray generation band 27A on the target 17A is disposed at a position facing the filament 16, and X-rays having a wavelength corresponding to the material (for example, Cu) are generated from the first X-ray generation band 27A.

  When the pressure state of the pressure switching device 65 is switched to the second pressure state, the vent hole 57 is brought into communication with the pressurizing pump 66 by the electromagnetic valve 60. In this state, the pressurizing pump 66 supplies a predetermined pressure to the surface of the target flange 35 on the target 17A side, and the flange 35 attempts to move to the target flange 35 to the side opposite to the target 17A (left side in FIG. 7). Power is applied. Although this force changes according to the area of the flange 35, in this embodiment, when the pressure from the pressurizing pump 66 is applied to the target flange 35, the flange 35 is evacuated by the target 17A side ( The size (area) of the flange 35 in the radial direction is set so that a force larger than the force drawn on the right side of FIG. Therefore, when the pressure state of the pressure switching device 65 is switched to the second pressure state, the flange 35 overcomes the vacuum suction force inside the casing 25 and moves to the left in FIG. The surface on the opposite side is stationary with the target-side inner wall of the projecting member 70 as the second contact member in contact. In this state, the second X-ray generation band 27B on the target 17A is disposed at a position facing the filament 16 (see FIG. 4), and X-rays having a wavelength corresponding to the material (for example, Mo) are emitted from the second X-ray generation band 27B. appear.

  As described above, in FIG. 7, if the pressure switching device 65 is set to the first pressure state (atmosphere communication state), X-rays having a wavelength corresponding to the first X-ray generation band 27A can be generated from the X-ray generation device 2C. On the other hand, if the pressure gas supply device 65 is set to the second pressure state (pressure supply state), X-rays having a wavelength corresponding to the second X-ray generation zone 27B can be generated from the X-ray generation device 2C. Even when the type of X-rays to be generated is switched in this way, the position of the filament 16 does not change, so that no positional change also occurs in the X-ray focal point F. Therefore, even when the type of X-rays generated from the X-ray generator 2C in FIG. 1 is changed, the position of the X-ray focal point F in the X-ray optical system does not change, and accordingly, the divergence slit 7 and the goniometer 3 are changed. This is very advantageous because it is not necessary to readjust the position of each element in the X-ray optical system.

  Furthermore, also in this embodiment, the target unit 24 is moved between the first position (FIG. 7) and the second position (see FIG. 4) based on the air pressure. Compared with the case where a more complicated power transmission system is used, the structure for the movement is simple, stable, and no breakdown occurs.

  Furthermore, in this embodiment, since the protruding member 70 does not have to be airtight with respect to the casing 25, it is not necessary to provide the airtight structure as applied to the protruding member 50 shown in FIG. The structure of the entire apparatus can be made simpler and less likely to fail.

(Third embodiment of X-ray generator)
FIG. 8 shows a third embodiment of the X-ray generator according to the present invention. In FIG. 8, the same reference numerals as those in FIG. 2 denote the same members, and description of those members is omitted. The X-ray generator 2D according to this embodiment differs from the embodiment shown in FIG. 2 in that the target 17B has four X-ray generation bands 27A, 27B, 27C, and 27D, and a ring shape. That is, a set bolt 72 as a third abutting member is provided at an appropriate position (a position shown in the lower part in FIG. 8) of the protruding member 50.

  The first X-ray generation band 27A, the second X-ray generation band 27B, the third X-ray generation band 27C, and the fourth X-ray generation band 27D are each formed of, for example, Cu, Mo, Cr, and Co. Note that the number of X-ray generation bands is not limited to four and can be a desired number of three or more as required. The set bolt 72 is fitted to a female screw provided on the projecting member 50, and its tip abutting surface (right end surface in FIG. 8) is rotated by rotating the head in the clockwise or counterclockwise direction around the axis. Moves in a direction approaching the flange 35 or away from the flange 35. The periphery of the set bolt 72 is hermetically held by an O-ring 73 that is a sealing material.

  The electromagnetic valve 60 in the pressure switching device 58 connects the pipe 59 to atmospheric pressure when the input voltage is in the OFF state. At this time, the force for pulling the flange 35 of the target unit 24 to the opposite side to the target 17B does not act. Therefore, the force for pulling the flange 35 of the target unit 24 to the opposite side to the target 17B is caused by the vacuum suction force. It will be less than the pulling force. As a result, the flange 35 is pulled by the vacuum suction force and moves in the direction of the target 17B, and stops in a state where the right side surface of the flange 35 is in contact with the tip step portion of the casing flange 49 as the first contact member.

  The positions of the target unit 24 and the flange 35 in this state are referred to as a first position. When the target flange 35 is in the first position, the first X-ray generation band 27A on the target flange 35 side on the target 17B is in a position facing the filament 16. Therefore, when electrons are emitted from the filament 16, X-rays are generated from the X-ray generation band 27A, and the X-rays are taken out from the X-ray window 28 to the outside. If the X-ray generation band 27A is made of Cu, X-rays having a wavelength corresponding to Cu are generated from the X-ray generator 2D.

  Next, the solenoid valve 60 connects the pipe 59 to the rotary pump 61 when the input voltage is in the ON state. Thereby, the pressure in the space area on the left side of the flange 35 is reduced by the rotary pump 61. At this time, the air suction force for moving the target flange 35 to the side opposite to the target 17 </ b> B changes according to the area of the target flange 35. In the present embodiment, the area of the target flange 35 is set so that the force for moving the target flange 35 to the side opposite to the target 17B is larger than the force for pulling the target flange 35 toward the target 17B by the vacuum suction force. It is set. Therefore, when the electromagnetic valve 60 is turned on and the left side of the target flange 35 is decompressed by the rotary pump 61, the force pulling the entire target unit 24 in the left direction becomes larger than the force pulling in the right direction. 24 moves to the left. The moving target unit 24 comes to rest with the left side surface of the target flange 35 coming into contact with the tip contact surface of a set bolt 72 as a third contact member.

  When the right side surface of the target flange 35 is in contact with the front end step portion of the casing flange 49 as the first contact member, the front end contact surface of the set bolt 72 generates X-rays with respect to the left side surface of the flange 35. If the target flange 35 moving to the left by the pressure reduction by the rotary pump 61 comes into contact with the tip abutting surface of the set bolt 72 and is stationary when the band 27A to 27D is separated by one width, the target 17B The second X-ray generation band 27 </ b> B is disposed at a position facing the filament 16. This position is referred to as the second position. If the second X-ray generation band 27B is made of Mo, X-rays having a wavelength corresponding to Mo are generated from the X-ray generator 2D.

  On the other hand, when the right side surface of the target flange 35 is in contact with the front end step portion of the casing flange 49 as the first contact member, the front end contact surface of the set bolt 72 is X with respect to the left side surface of the target flange 35. If each of the line generating bands 27A to 27D is separated by a width corresponding to two or three, the target flange 35 that moves to the left by the pressure reduction by the rotary pump 61 is the tip contact surface of the set bolt 72 in each case. The third X-ray generation band 27C or the fourth X-ray generation band 27D of the target 17B is disposed at a position facing the filament 16 when the target 17B comes to rest. The position where the third X-ray generation band 27C faces the filament 16 is referred to as a third position, and the position where the fourth X-ray generation band 27D faces the filament 16 is referred to as a fourth position. If the third X-ray generation band 27C is formed of Cr, X-rays having a wavelength corresponding to Cr are generated from the X-ray generator 2D, and if the fourth X-ray generation band 27D is formed of Co, the Co X-rays with corresponding wavelengths are generated from the X-ray generator 2D.

  As described above, according to the present embodiment, the first X-ray generation band 27 </ b> A is opposed to the filament 16 by the ON / OFF control of the pressure switching device 58 and the position adjustment of the tip contact surface of the set bolt 72. A second position where the second X-ray generation band 27B faces the filament 16, a third position where the third X-ray generation band 27C faces the filament 16, or a fourth position where the fourth X-ray generation band 27D faces the filament 16. The counter cathode 17B can be arranged at any desired position. Then, X-rays having different wavelengths can be generated at each position. Since X-rays with four types of wavelengths can be generated, various X-ray analyzes can be performed. Of course, if the number of X-ray generation bands is four or more, further various X-ray analyzes can be performed. The specific structure of the third contact member is not limited to the illustrated set bolt 72.

  Even when the type of X-rays to be generated is changed as described above, since the position of the filament 16 does not change, the position of the X-ray focal point F does not change. Therefore, even when the type of X-rays generated from the X-ray generator 2D in FIG. 1 is changed, the position of the X-ray focal point F in the X-ray optical system does not change, and accordingly, the divergence slit 7 and the goniometer 3 are changed. This is very advantageous because it is not necessary to readjust the position of each element in the X-ray optical system.

  Furthermore, in this embodiment, since the target unit 24 is moved between the first position to the fourth position based on air pressure, an electric device such as a motor is used as a power source, and a more complicated power transmission system Compared with the case of using, the structure for the movement is simple, stable and no failure occurs.

(Fourth embodiment of X-ray generator)
FIG. 10 shows a fourth embodiment of the X-ray generator according to the present invention. In FIG. 10, the same reference numerals as those in FIG. 2 denote the same members, and a description of these members is omitted. The X-ray generator 2F according to this embodiment is different from the embodiment shown in FIG. 2 as follows.

  (1) In the embodiment of FIG. 2, the stepped portion of the casing flange 49 formed inside the casing 25 is used as the first contact member for the target flange 35. On the other hand, in the present embodiment shown in FIG. 10, the casing wall 25a of the casing 25 is formed thin at a portion other than the storage portion of the filament 16 (upper end portion in FIG. 10), and the tip end surface portion of the thinned casing wall 25a is formed. Is used as the first contact member for the target flange 35. That is, the side wall of the casing 25 itself is used as the first contact member.

  (2) In the embodiment of FIG. 2, the outer peripheral surface of the target flange 35 is slidably supported by the opening side tip of the casing 25. On the other hand, in the present embodiment shown in FIG. 10, the protruding member 50 is attached to a part of the casing 25 (lower part of FIG. 10) by the bolt 74, and the outer peripheral surface of the target flange 35 is slid by the side wall portion of the protruding member 50. I support it as possible.

  (3) In the embodiment of FIG. 2, a ventilation hole 57 is provided in the casing 25, and one end of the ventilation hole 57 is opened toward the target flange 35 at the stepped portion of the casing flange 49. On the other hand, in the present embodiment shown in FIG. 10, the side wall 25 a of the casing 25 is formed thin at a portion other than the storage portion of the filament 16 (upper end portion in FIG. 10). An opening (that is, a gap) is formed between the protruding member 50 and the inner peripheral surface of the side wall portion, and atmospheric pressure is applied to the target flange 35 through the opening.

  According to the X-ray generator 2F configured as described above, the position at which the target flange 35 abuts on the tip end surface portion of the casing wall 25a as the first abutting member by the ON / OFF control of the pressure switching device 58; The projecting member 50 as the second abutting member can be translated between the projecting member 50 and the position that abuts against the target-side inner wall portion. And by this parallel movement, the X-ray generation bands 27A and 27B facing the filament 16 can be switched, and the wavelength of the generated X-ray can be switched.

(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
In the above embodiment, the rotary targets 17A (FIG. 2) and 17B (FIG. 8) are employed as the counter cathode. In the present invention, it is possible to use a fixed target instead of such a rotary target. When a rotary type target is used, as shown in FIG. 3, the counter-cathode extending portion that extends from the target 17A and to which the flange 35 is attached accommodates the direct drive mechanism 40 that is a rotary drive device. An anti-cathode housing 26 is used. When a fixed target is used, a rotary drive device is not necessary, and therefore the anti-cathode extension is constituted by a portion extending from the target in some form.

  In the embodiment shown in FIG. 2, the target 17A can be translated in the direction of the axis X0 by both the casing flange 49 formed inside the casing 25 and the ring-shaped protruding member 50 fixed to the left end surface of the casing 25. An anti-cathode support means for supporting was constructed. However, the counter-cathode support means may be formed by only one of the casing flange 49 and the protruding member 50. Further, the counter-cathode support means may be constituted by an appropriate member or structure other than the casing flange 49 and the protruding member 50.

  In the embodiment shown in FIG. 2, the first contact member that contacts the surface of the target flange 35 on the target 17 </ b> A side is configured by the tip step portion of the casing flange 49. However, the first contact member can be configured by any member other than the casing flange 49. Further, the second abutting member that abuts the surface of the target flange 35 opposite to the target 17 </ b> A is configured by the target-side inner wall portion of the protruding member 50. However, the second contact member can be configured by any member other than the protruding member 50.

1 is a plan view of an X-ray diffraction apparatus which is an embodiment of an X-ray analysis apparatus according to the present invention. It is a top view which shows one Embodiment of the X-ray generator which concerns on this invention. FIG. 3 is a plan sectional view showing an embodiment of an anti-cathode used in the X-ray generator of FIG. 2. It is sectional drawing which shows the state of the operation | movement time point different from the case of FIG. 2 of the X-ray generator shown in FIG. It is a figure for demonstrating the aerodynamic force which drives a target unit. It is sectional drawing which shows other embodiment of the X-ray generator which concerns on this invention. It is sectional drawing which shows other embodiment of the X-ray generator which concerns on this invention. It is sectional drawing which shows other embodiment of the X-ray generator which concerns on this invention. It is sectional drawing which shows other embodiment of the X-ray generator which concerns on this invention. It is sectional drawing which shows other embodiment of the X-ray generator which concerns on this invention.

Explanation of symbols

1. X-ray diffractometer (X-ray analyzer),
2A, 2B, 2C, 2D, 2E, 2F. X-ray generator,
3. Goniometer, 4. 5. θ turntable, 5.2θ turntable, 6. Detector arm,
7). Divergent slit, 10. Sample holder, 11. Scattering slit,
12 Light receiving slit, 13. X-ray counter (X-ray detection means),
16. Filament (cathode), 17A, 17B. Target (anti-cathode),
20. θ rotation driving device, 21.2 θ rotation driving device, 24. Target unit,
25. Casing, 26. Anti-cathode housing (anti-cathode extension),
27A, 27B, 27C, 27D. X-ray generation zone, 28. X-ray window, 30. First inner pipe,
31. Second inner pipe, 32. Target bottom, 33. Partition member,
35. Target flange, 36. Inner sliding part 36a. Sliding surface,
37a, 37b, 37c. O-ring, 38. Magnetic seal device, 39,41. bearing,
40. Direct drive mechanism, 42. Sealing material, 43. Outer sliding part,
44. Rotor, 45. Stator coil, 46. Water supply port 47. Drainage port,
49. Casing flange (first contact member, anti-cathode support member),
50. 51. protruding member (second contact member, counter-cathode support member) O-ring, 54. Piping,
55. Turbomolecular pump, 56. Rotary pump, 57. Vents,
58. Pressure switching device, 59. Piping, 60.3 port solenoid valve,
61. Rotary pump 62A, 62B, 62C. Control device,
65. Pressure switching device, 66. Pressure pump, 70. Protruding member,
72. Stop bolt (third abutting member), 73. O-ring, Cg. Goniometer circle,
Cf. Concentrated circle, F. X-ray focus, R1, R2. X-ray, S. sample,
θ. X-ray incident angle, 2θ. X-ray diffraction angle, α. X-ray extraction angle, ω. Center axis

Claims (12)

A cathode that generates electrons;
An anti-cathode provided with two X-ray generating bands provided opposite to the cathode and arranged adjacent to each other;
A casing containing the cathode and the counter cathode therein;
Decompression means for decompressing the inside of the casing;
Anti-cathode support means for supporting the anti-cathode so as to be movable in the direction in which the X-ray generation bands are arranged;
A flange that moves integrally with the counter-cathode;
When the counter-cathode is in a first position where the X-ray generation band on the side closer to the flange of the two X-ray generation bands is placed in a region where it collides with the electrons, A first contact member that contacts the surface;
When the counter-cathode is in a second position where the X-ray generation band on the side farther from the flange of the two X-ray generation bands is placed in a region where it collides with the electrons, opposite to the counter-cathode of the flange A second abutting member that abuts against the side surface;
Flange pressure adjusting means for switching the air pressure applied to the flange between a first pressure state and a second pressure state;
The first pressure state is a force that moves the flange to the side opposite to the counter cathode, and a force that is smaller than a force that pulls the flange to the counter cathode side based on a reduced pressure state inside the casing. , The pressure applied to the flange,
The second pressure state is a force that moves the flange to the side opposite to the counter-cathode, and a force that is greater than a force that pulls the flange toward the counter-cathode side based on a reduced pressure state inside the casing. The X-ray generator is in a pressure state applied to the flange. The X-ray generator according to claim 1,
An anti-cathode extension extending from the anti-cathode and having the flange attached thereto;
The counter-cathode support means is constituted by a part of the casing, and a part of the casing supports the counter-cathode by slidingly contacting the counter-cathode extension and supporting the counter-cathode extension. X-ray generator. The X-ray generator according to claim 2,
The X-ray generator according to claim 1, wherein the first contact member is constituted by another part of the casing. In the X-ray generator as described in any one of Claims 1-3,
The casing has an opening for inserting the counter-cathode, and the opening is provided with a protruding member protruding toward the center of the opening, and the second contact member is the protruding An X-ray generator characterized by comprising members.   5. The X-ray generator according to claim 4, wherein an inner peripheral surface of the projecting member constitutes the counter-cathode support means.   6. The X-ray generator according to claim 1, further comprising a fixing unit that fixes the flange so as not to be movable when the counter-cathode is in the second position. X-ray generator. In the X-ray generator as described in any one of Claims 1-6,
The flange pressure adjusting means is
Means for applying an atmospheric pressure to the surface of the flange on the counter-cathode side;
An X-ray generator comprising: first pressure switching means for switching a region adjacent to the surface of the flange opposite to the counter-cathode between a reduced pressure state and an atmospheric pressure state. The X-ray generator according to claim 7,
The X-ray generator according to claim 1, wherein the first pressure switching means also serves as the decompression means for decompressing the inside of the casing to bring the region into a decompressed state. In the X-ray generator as described in any one of Claims 1-6,
The flange pressure adjusting means is
Means for applying atmospheric pressure to the surface of the flange opposite to the counter-cathode;
An X-ray generator comprising: second pressure switching means for switching a pressure applied to the surface of the flange on the counter-cathode side between an atmospheric pressure state and a state equal to or higher than atmospheric pressure. A cathode that generates electrons;
An anti-cathode provided with a plurality of X-ray generating bands provided opposite to the cathode and arranged adjacent to each other;
A casing containing the cathode and the counter cathode therein;
Decompression means for decompressing the inside of the casing;
Anti-cathode support means for supporting the anti-cathode so as to be movable in the direction in which the X-ray generation bands are arranged;
A flange that moves integrally with the counter-cathode;
The surface on the counter-cathode side of the flange when the counter-cathode is in a position where the X-ray generation band that is closest to the flange among the plurality of X-ray generation bands is placed in a region that collides with the electrons A first abutting member that abuts on
A third abutting member capable of abutting against a surface of the flange opposite to the counter-cathode;
Flange pressure adjusting means for switching the air pressure applied to the flange between a first pressure state and a second pressure state;
The first pressure state is a force that moves the flange to the side opposite to the counter cathode, and a force that is smaller than a force that pulls the flange to the counter cathode side based on a reduced pressure state inside the casing. , The pressure applied to the flange,
The second pressure state is a force that moves the flange to the side opposite to the counter-cathode, and a force that is greater than a force that pulls the flange toward the counter-cathode side based on a reduced pressure state inside the casing. , The pressure applied to the flange,
The position where the third abutting member comes into contact with the flange is such that each of the X-ray generation bands other than the X-ray generation band that is closest to the flange among the plurality of X-ray generation bands collides with the electrons. An X-ray generator capable of being changed corresponding to each position of the flange when placed in a region to be operated. A cathode that generates electrons;
An anti-cathode provided with two X-ray generating bands provided opposite to the cathode and arranged adjacent to each other;
A casing containing the cathode and the counter cathode therein;
Decompression means for decompressing the inside of the casing;
Counter-cathode rotation driving means for rotating the counter-cathode around an axis passing through the counter-cathode;
An anti-cathode housing which accommodates the counter-cathode rotation driving means and extends from the counter-cathode;
A flange provided on an outer peripheral surface of the counter-cathode housing and projecting in a radial direction of the counter-cathode housing;
Anti-cathode support means for supporting the anti-cathode housing movably in the axial direction of the anti-cathode housing;
A first abutting member that stops movement of the flange toward the cathode side;
A second abutting member that stops movement of the flange to the opposite side of the counter-cathode;
Flange pressure adjusting means for switching the air pressure applied to the flange between a first pressure state and a second pressure state;
The first pressure state is a force that moves the flange to the side opposite to the counter cathode, and a force that is smaller than a force that pulls the flange to the counter cathode side based on a reduced pressure state inside the casing. , The pressure applied to the flange,
The second pressure state is a force that moves the flange to the side opposite to the counter cathode, and is more than a force that pulls the flange in the direction in which the counter cathode exists based on a reduced pressure state inside the casing. A pressure state in which a large force is applied to the flange;
The first abutting member has the counter-cathode at a first position where an X-ray generation band on the side closer to the flange of the two X-ray generation bands is placed in a region where it collides with the electrons. Abuts against the surface of the flange on the counter-cathode side,
The second contact member has the counter cathode at a second position where an X-ray generation band on the side farther from the flange of the two X-ray generation bands is placed in a region where it collides with the electrons. An X-ray generating apparatus, wherein the X-ray generator is in contact with a surface of the flange opposite to the counter cathode.   An X-ray analysis apparatus comprising: the X-ray generation apparatus according to any one of claims 1 to 11; and an X-ray optical system using X-rays generated from the X-ray generation apparatus.

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