JP5759257B2 - X-ray equipment - Google Patents

Description

  The present invention relates to an X-ray apparatus.

  In Patent Documents 1 and 2, secondary X-rays (fluorescent X-rays or scattered X-rays) generated by a sample irradiated with X-rays are detected by a detection unit, and X-ray pulse irradiation and detection units are detected. An invention that synchronizes operation with each other is described. That is, charge is accumulated by secondary X-ray detection in the detection unit when the sample is irradiated with X-rays, and charge is read out in the detection unit when the sample is not irradiated with X-rays.

  In the invention described in Patent Document 1, as a mechanism for generating pulsed X-rays, the application of a deflection coil in an X-ray source is controlled to allow / prohibit the arrival of an electron beam to an X-ray generation target. Mechanism, a mechanism for permitting / prohibiting the arrival of the electron beam to the X-ray generation target by rotating the shielding disk having the slit in the X-ray source, and rotating the shielding disk having the slit in the X-ray source And a mechanism for permitting / prohibiting the passage of X-rays and a mechanism for permitting / prohibiting the passage of X-rays by rotating a shielding disk having a slit outside the X-ray source. . Patent Document 2 does not describe a mechanism for generating pulsed X-rays.

JP-A-5-243123 JP 2008-256587 A

  Among the pulse X-ray generation mechanisms, the mechanism that controls the applied voltage of the deflection coil in the X-ray source has a problem that the X-ray output becomes unstable. The mechanism for rotating the shielding disk within the X-ray source has a problem that the structure of the X-ray source becomes complicated. In addition, the mechanism for permitting / prohibiting the passage of X-rays by rotation of the shielding disk inside or outside the X-ray source requires the use of a shielding disk made of a metal having a large atomic number in order to block X-rays. In addition, since it is necessary to rotate the heavy shielding disk, there is a problem that the structure is complicated in this respect as well.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an X-ray apparatus capable of generating a stable pulse X-ray with a simple configuration.

The X-ray apparatus of the present invention includes: (1) an X-ray source that continuously diverges and outputs X-rays from an X-ray output window ; and (2) a multicapillary X-ray lens having a tapered portion near the input end. wherein the output end of the multi-capillary X-ray lens X-rays input from the X-ray source to the input terminal when the multi-capillary X-ray lens is placed in a particular orientation with respect to the X-ray output direction from the X-ray source And an irradiation unit that does not output X-rays from the output end when the multicapillary X-ray lens is arranged in an orientation different from the specific orientation, and (3) controls the orientation of the multi-capillary X-ray lens of the irradiation unit And a control unit.

  The X-ray apparatus of the present invention (1) inputs secondary X-rays generated in a sample when the sample is irradiated with X-rays output from the output end of the irradiation unit, and inputs the secondary X-rays. And a detector that reads and stores the accumulated charge, and (2) the control unit causes the irradiation unit to be arranged in a specific direction to output X-rays from the output end of the irradiation unit. The charge storage operation is performed in the detection unit when the light is being emitted, and the charge read operation is performed in the detection unit when the irradiation unit is arranged in an orientation different from the specific direction and X-rays are not output from the output end of the irradiation unit. Is preferred.

  The X-ray apparatus of the present invention further includes (1) an imaging unit that forms an image of secondary X-rays generated on the sample on the light receiving surface of the detection unit, and (2) the detection unit is on the light receiving surface. It is preferable to detect a secondary X-ray image having a two-dimensional pixel structure and imaged on the light receiving surface by the imaging unit.

In X-ray device of the present invention, detection unit is preferably includes a CCD, also it is preferable that the imaging unit includes a grazing incidence mirror with a hyperboloid of revolution and a spheroid.

  According to the present invention, stable pulse X-rays can be generated with a simple configuration.

It is a lineblock diagram of X-ray device 1 of this embodiment. It is a figure explaining the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a figure explaining the mechanism of the movement of the azimuth | direction of the illumination part 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of this embodiment. It is a timing chart which shows operation | movement of the X-ray apparatus 1 of this embodiment. It is a block diagram of the X-ray apparatus 2 of a comparative example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a configuration diagram of an X-ray apparatus 1 of the present embodiment. The X-ray apparatus 1 shown in this figure includes an X-ray source 10, an irradiation unit 20, an imaging unit 30, a detection unit 40, a vacuum container 50, and a control unit 60.

  The X-ray source 10 outputs X-rays continuously. The irradiation unit 20 has an input end 21 and an output end 22. When the X-ray reaches the input end 21 along a specific direction, the X-ray can be output from the output end 22. That is, the illumination unit 20 outputs X-rays input from the X-ray source 10 to the input end 21 from the output end 22 when arranged in a specific direction with respect to the X-ray output direction from the X-ray source 10. be able to. On the other hand, the illumination unit 20 cannot output X-rays from the output end 22 when it is arranged in an orientation different from the specific orientation.

  The illumination unit 20 preferably includes a multi-capillary X-ray lens (MCX). The multicapillary X-ray lens is a bundle of a plurality of hollow tubes, and can output X-rays input to one end of each hollow tube from the other end. The illumination unit 20 including a multi-capillary X-ray lens efficiently inputs X-rays that are diverged and output from the X-ray output window of the X-ray source 10 because the vicinity of the input end 21 has a tapered shape. Can do. The illumination unit 20 including a multi-capillary X-ray lens can converge and output X-rays from the output end 22 when the vicinity of the output end 22 has a tapered shape. The illumination unit 20 including such a multi-capillary X-ray lens cannot output X-rays from the output end 22 only by slightly changing from a specific direction in which X-rays can be output from the output end 22. .

  The detection unit 40 inputs secondary X-rays (fluorescent X-rays or scattered X-rays) generated in the sample 90 when the sample 90 is irradiated with the X-rays output from the output end 22 of the irradiation unit 20. Charges can be generated and stored according to the input of the secondary X-ray, and the stored charges can be read out. The detection unit 40 preferably has a two-dimensional pixel structure on the light receiving surface and can detect a secondary X-ray image formed on the light receiving surface. The detection unit 40 may be anything as long as it has sensitivity to secondary X-rays, and preferably includes a CCD (Charge Coupled Device).

  The imaging unit 30 is provided between the sample 90 and the detection unit 40. The imaging unit 30 can form an image of secondary X-rays generated on the sample 90 on the light receiving surface of the detection unit 40. The imaging unit 30 preferably includes a grazing incidence mirror having a rotating hyperboloid and a rotating ellipsoid. The imaging unit 30 is preferably capable of enlarging and imaging the secondary X-ray image generated by the sample 90 on the light receiving surface of the detection unit 40.

  The vacuum vessel 50 has an X-ray transmission window 51, the image forming unit 30 is disposed therein, and is connected to the detection unit 40 through a vacuum flange. The X-ray transmission window 51 transmits secondary X-rays generated in the sample 90 into the vacuum container 50. The imaging unit 30 can form an image of secondary X-rays input from the X-ray transmission window 51 into the vacuum vessel 50 on the light receiving surface of the detection unit 40. The vacuum vessel 50 can reduce the attenuation of secondary X-rays that are input from the X-ray transmission window 51 and reach the light receiving surface of the detection unit 40 by reducing the pressure inside. Note that the vacuum vessel 50 can reduce the attenuation of the secondary X-rays even if the inside is not decompressed and He gas is contained therein. When the attenuation of secondary X-rays in the atmosphere does not matter (for example, when the secondary X-rays have high energy), the vacuum vessel 50 is unnecessary.

  The control unit 60 controls the direction of the irradiation unit 20 and controls the operation of the detection unit 40. Specifically, the control unit 60 causes the detection unit 40 to perform a charge accumulation operation when the irradiation unit 20 is arranged in a specific orientation and X-rays are output from the output end 22 of the irradiation unit 20. In addition, the control unit 60 causes the detection unit 40 to perform a charge reading operation when the irradiation unit 20 is arranged in an orientation different from the specific orientation and X-rays are not output from the output end 22 of the irradiation unit 20.

  Although not shown in FIG. 1, each of the irradiation unit 20, the imaging unit 30, the detection unit 40, and the sample 90 can be moved by a movable stage for focus adjustment and the like. . In particular, as shown in FIG. 2, the illumination unit 20 is parallel to the direction perpendicular to the z-axis with respect to the X-ray output direction (z-axis direction) from the X-ray output window 11 of the X-ray source 10. Movement and rotational movement about an axis perpendicular to the z-axis is possible. FIG. 2 shows an xyz rectangular coordinate system for convenience of explanation.

  By this movement, the illumination unit 20 is switched between a specific direction in which X-rays can be output from the output end 22 and a direction in which X-rays cannot be output from the output end 22. The movement of the azimuth of the illumination unit 20 is preferably a high-speed and high-precision movement of about several hundred μm, or a rotation movement of about 1 degree within about 10 milliseconds. The movement of the illumination unit 20 is preferably performed by a stage using a piezo element or a pulse motor.

  3 to 8 are diagrams for explaining an example of a mechanism for moving the azimuth of the illumination unit 20 with respect to the X-ray output direction from the X-ray source 10 in the X-ray apparatus 1 of the present embodiment. These drawings also show an xyz rectangular coordinate system for convenience of explanation.

  The illumination unit moving mechanism 70A shown in FIG. 3 holds the illumination unit 20 with a holder 71, and fixes the holder 71 to a movable stage 73 that can move in the y-axis direction with respect to the fixed stage 72. The movable stage 73 is moved in the y-axis direction by the motor-driven drive unit 74, whereby the illumination unit 20 can be moved in the y-axis direction.

  The illumination unit moving mechanism 70B shown in FIG. 4 holds the illumination unit 20 with a holder 71, and fixes the holder 71 to a movable stage 73 that can move in the x-axis direction with respect to the fixed stage 72, so The movable stage 73 is moved in the x-axis direction by the motor-driven drive unit 74, whereby the illumination unit 20 can be moved in the x-axis direction.

  The illumination unit moving mechanism 70C shown in FIG. 5 holds the illumination unit 20 with a holder 71, and fixes the holder 71 to a movable stage 73 that can be rotated around the x axis with respect to the fixed stage 72. The movable stage 73 is rotationally moved around the x axis by the drive unit 74 using a pulse motor, whereby the illumination unit 20 can be rotationally moved around the x axis. At this time, the center of rotation of the illumination unit 20 around the x axis is located at the center of the illumination unit 20.

  The illumination unit moving mechanism 70D shown in FIG. 6 holds the illumination unit 20 with a holder 71, and fixes the holder 71 to a movable stage 73 that can be rotated about the y axis with respect to the fixed stage 72. The movable stage 73 is rotationally moved around the y axis by the drive unit 74 using a pulse motor, whereby the illumination unit 20 can be rotationally moved around the y axis. At this time, the center of rotation of the illumination unit 20 around the y-axis is located at the center of the illumination unit 20.

  The illumination unit moving mechanism 70E shown in FIG. 7 holds the illumination unit 20 with a holder 71 near one end of the illumination unit 20, fixes the holder 71 to a fixed stage 72, and a drive unit 74 using a piezoelectric element or a pulse motor. The illumination unit 20 is moved in the y-axis direction in the vicinity of the other end of the illumination unit 20, so that the illumination unit 20 can be rotated around the x-axis.

  The illumination unit moving mechanism 70F shown in FIG. 8 holds the illumination unit 20 with a holder 71 near one end of the illumination unit 20, fixes the holder 71 to a fixed stage 72, and a drive unit 74 using a piezoelectric element or a pulse motor. The illuminating unit 20 is moved in the x-axis direction near the other end of the illuminating unit 20, so that the illuminating unit 20 can be rotated around the y-axis.

  The X-ray apparatus 1 of this embodiment is controlled by the control unit 60 and operates as follows. FIG. 9 is a timing chart showing the operation of the X-ray apparatus 1 of the present embodiment. The illuminating unit 20 has a specific azimuth capable of outputting X-rays from the output end 22 and an azimuth incapable of outputting X-rays from the output end 22 according to a control signal given from the control unit 60 to the driving unit 74. Are switched alternately.

  When the control signal given from the control unit 60 to the drive unit 74 is at a high level, the illumination unit 20 is arranged in a specific direction. During the period in which the irradiation unit 20 is arranged in a specific direction, the X-rays output from the X-ray source 10 are input to the input end of the irradiation unit 20, output from the output end 22, and irradiated to the sample 90. The secondary X-rays generated in the sample 90 by the X-ray irradiation to the sample 90 are transmitted through the X-ray transmission window 51 and input into the vacuum vessel 50, and the detection unit 40 is detected by the imaging unit 30 in the vacuum vessel 50. An image is formed on the light receiving surface. During this period, the detection unit 40 generates and accumulates charges in response to the input of secondary X-rays in each pixel on the light receiving surface.

  On the other hand, when the control signal given from the control unit 60 to the drive unit 74 is at a low level, the illumination unit 20 is arranged in a direction different from the specific direction. Even if the X-rays output from the X-ray source 10 reach the input end of the irradiation unit 20 during the period in which the irradiation unit 20 is arranged in a different direction from the specific direction, the X-rays are output from the output end 22 of the irradiation unit 20. Not output. Therefore, secondary X-rays from the sample 90 do not reach the detection unit 40. During this period, the detection unit 40 reads the charge accumulated in each pixel so far, and obtains a voltage value corresponding to the charge amount of each pixel.

  A secondary X-ray image on the light receiving surface of the detection unit 40 is obtained by a voltage value corresponding to the amount of charge of each pixel output from the detection unit 40. In addition, X-ray energy analysis at each pixel of the detection unit 40 becomes possible.

  X-ray energy analysis in each pixel of the detection unit 40 is performed as follows. The exposure time (the time during which the illumination unit 20 is arranged in a specific direction) and the X-ray irradiation intensity are set so that one X-ray photon enters each pixel of the CCD as the detection unit 40. X-ray photons input to one pixel generate electrons and holes in the semiconductor crystal of the CCD. The CCD is made of a Si semiconductor, and the energy required to generate electron / hole pairs is about 3.7 eV. If the incident X-ray energy is Ex (eV), Ex / 3.7 electrons are generated in the depletion layer of the CCD. Due to the electric field applied to the depletion layer, the electrons gather at the electrodes and are sequentially transferred to the outside. In other words, since the number of generated electrons depends on the energy of incident X-rays, the X-ray energy can be determined by measuring the number of electrons (that is, the amount of charge). Therefore, an X-ray energy spectrum can be obtained by recording the signal intensity at each pixel for an image adjusted to have one photon per pixel, acquiring a plurality of the images, and creating a histogram thereof.

  Next, the advantages of the X-ray apparatus 1 of the present embodiment will be described in comparison with the case of the X-ray apparatus 2 of the comparative example shown in FIG. In the X-ray apparatus 2 of the comparative example, the irradiation unit 20 is always arranged in a specific direction, and the shutter 80 is provided in the vacuum container 50, and the opening / closing operation of the shutter 80 and the operation of the detection unit 40 are synchronized with each other.

  In the X-ray apparatus 2 of the comparative example, when the energy of the secondary X-ray generated in the sample 90 is high, depending on the material of the shutter 80, the shutter 80 is closed and the charge reading is performed in the detection unit 40. However, secondary X-rays may pass through the shutter 80 and enter the detector 40. On the other hand, in the X-ray apparatus 1 according to the present embodiment, X-rays are not irradiated when the detection unit 40 is reading out charges, so that the image accumulated in the detection unit 40 is not affected.

  Further, in the X-ray apparatus 2 of the comparative example, the shutter 80 also needs to be installed in the vacuum vessel 50, resulting in a complicated apparatus configuration. In addition, in the X-ray apparatus 2 of the comparative example, when the inside of the vacuum vessel 50 is depressurized, it is necessary to use a vacuum-use member as the member of the shutter 80, grease, etc., which is expensive. Further, in the X-ray apparatus 2 of the comparative example, it is conceivable to dispose the shutter 80 outside the vacuum vessel 50, but in this case, the portion is subject to attenuation by the atmosphere and the X-ray transmission window 51. On the other hand, in the X-ray apparatus 1 of this embodiment, since the shutter 80 is unnecessary, the apparatus configuration is simple, the cost is low, and attenuation due to the atmosphere is reduced.

  Furthermore, the X-ray output becomes unstable when generating pulsed X-rays by controlling the voltage applied to the deflection coil in the X-ray source to permit / prohibit the arrival of the electron beam to the X-ray generation target. On the other hand, in the X-ray apparatus 1 of the present embodiment, an X-ray source that continuously outputs X-rays can be used, so that a stable pulse X-ray output can be obtained.

  DESCRIPTION OF SYMBOLS 1, ... X-ray apparatus, 10 ... X-ray source, 11 ... X-ray output window, 20 ... Irradiation part, 21 ... Input end, 22 ... Output end, 30 ... Imaging part, 40 ... Detection part, 50 ... Vacuum Container, 51 ... X-ray transmission window, 60 ... Control unit, 70A to 70F ... Illumination unit moving mechanism, 71 ... Holder, 72 ... Fixed stage, 73 ... Movable stage, 74 ... Drive unit, 80 ... Shutter, 90 ... Sample.

Claims (5)

An X-ray source that continuously emits and outputs X-rays from the X-ray output window ;
The X-ray is obtained when a portion near the input end includes a multicapillary X-ray lens having a tapered shape, and the multicapillary X-ray lens is arranged in a specific direction with respect to the X-ray output direction from the X-ray source. X-rays inputted to the input terminal from a source output from an output end of the multi-capillary X-ray lens, the output terminal X-rays when the multi-capillary X-ray lens is disposed in an azimuth different from the particular orientation Irradiating part that does not output from,
A control unit for controlling the orientation of the multi-capillary X-ray lens of the irradiation unit;
An X-ray apparatus comprising: The secondary X-ray generated in the sample is input when the sample is irradiated with the X-ray output from the output end of the irradiation unit, and a charge is generated in response to the input of the secondary X-ray. It further comprises a detection unit that accumulates and reads the accumulated charge,
The control unit causes the detection unit to perform a charge accumulation operation when the irradiation unit is arranged in the specific orientation and X-rays are output from the output end of the irradiation unit, and the irradiation unit is specified. When the X-ray is not output from the output end of the irradiating unit by being arranged in a different direction from the azimuth, a charge reading operation is performed in the detection unit
The X-ray apparatus according to claim 1. An image forming unit that forms an image of secondary X-rays generated in the sample on a light receiving surface of the detection unit;
The detection unit has a two-dimensional pixel structure on the light receiving surface, and detects an image of secondary X-rays imaged on the light receiving surface by the imaging unit;
The X-ray apparatus according to claim 2. The X-ray apparatus according to claim 2, wherein the detection unit includes a CCD. The X-ray apparatus according to claim 3, wherein the imaging unit includes a grazing incidence mirror having a rotating hyperboloid and a rotating ellipsoid.

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