JP2006337122A - X-ray spectroscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray spectroscope that has a small workpiece region, large wavelength scan range, and high resolution. <P>SOLUTION: X-rays discharged from a micro region regarded substantially as a point on a sample are made parallel by a multi-capillary X-ray lens, and are dispersed and reflected by first and second parallel dispersive crystals 51 and 52 arranged in parallel with each other, thereby always making outgoing X-rays 55 parallel with incoming X-rays 54. Thus, an X-ray detector 56 is required only to move linearly in the direction perpendicularly to the incoming/outgoing X-rays 54 and 55. The first and second parallel dispersive crystals 51 and 52 are rotated and moved for dispersion while the above relation is always kept using a parallelogram link AEFD. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an X-ray spectrometer used in an X-ray fluorescence analyzer, an electron probe microanalyzer (EPMA), a scanning electron microscope (SEM), and the like.

  These analyzers and the like are equipped with an X-ray spectrometer that analyzes the X-ray emitted from the micro area and detects its intensity in order to analyze the micro area on the sample. In such an X-ray spectroscopic apparatus, when emphasizing energy resolution, a curved crystal X-ray spectroscope 11 and a semiconductor detector 12 have been conventionally used as shown in FIG.

Recently, an X-ray spectroscope combining a multicapillary 21 and a flat plate crystal 22 utilizing a condensing and collimating function of a multicapillary as shown in FIG. 2 has also been proposed (Patent Document 1).
Japanese Unexamined Patent Publication No. 2004-294168 ([0021], FIG. 1)

  In both the method shown in FIG. 1 and the method shown in FIG. 2, the arm to which the detectors 12 and 23 are fixed needs to be rotated at an angle twice that of the axis of rotation of the spectral crystals 11 and 22. Therefore, when wavelength scanning is performed in a wide range, the rotation range of the detector fixing arm is widened and a two-dimensionally wide work area is required. However, the internal space of EPMA and SEM is not originally large, and various optional parts other than the X-ray spectrometer need to be attached, so that there are large spatial and location restrictions. For this reason, the above-described method has problems such as limitations on the X-ray spectral range and the inability to use a high-resolution spectroscope.

  The problem to be solved by the present invention is to provide a high-resolution X-ray spectrometer suitable for use in EPMA, SEM, etc., having a small work area and a wide wavelength scanning range.

An X-ray spectrometer according to the present invention, which has been made to solve the above problems,
An X-ray spectrometer that wavelength-disperses X-rays emitted from a minute region that can be regarded as a point on a sample,
A multicapillary X-ray lens having a point focal point on the incident end face side facing the sample and emitting substantially parallel light on the exit end face side;
A first flat plate spectral crystal disposed on the outgoing X-ray optical path of the multicapillary X-ray lens;
A second flat plate spectral crystal having the same lattice constant as that of the first flat plate spectral crystal and disposed parallel to the first flat plate spectral crystal on the optical path of the X-ray reflected by the first flat plate spectral crystal;
A driving mechanism for rotating the first flat plate spectral crystal around the X-ray irradiation surface and moving the second flat plate spectral crystal while maintaining a parallel relation to the first flat plate spectral crystal;
It is characterized by providing.

  In the X-ray spectrometer of the present invention, two flat plate crystal crystals having the same lattice constant are always rotated while maintaining a parallel relationship, so that X-rays (incident X-rays) emitted in parallel from the multicapillary X-ray lens are After being reflected and split by both plate spectral crystals, they are always emitted parallel to the incident X-rays regardless of their spectral wavelengths, and their height direction (perpendicular to the incident / exit X-rays) according to the rotation of the plate spectral crystals. The position in the right direction) only changes. Therefore, even if the spectroscopic crystal is rotated, the X-ray detector only needs to move linearly in a direction perpendicular to the direction of the outgoing X-ray (incident X-ray). There is no need to rotate. As a result, the X-ray spectrometer according to the present invention can be operated even in a narrow work area, and in an apparatus such as EPMA or SEM, there is a margin of space due to the size of the apparatus main body and the competition with other optional parts. It is possible to easily attach even when there are few. That is, the X-ray spectrometer of the present invention is suitable for use with a compact and high-performance apparatus.

  As a first embodiment of the X-ray spectrometer of the present invention, a configuration example in which a first flat plate spectral crystal and a second flat plate spectral crystal are fixed in a parallel state will be described. In this example, as shown in FIG. 3, the first flat plate spectral crystal 31 and the second flat plate spectral crystal 32 are fixed in parallel with each other. The center line 33 is rotatable. The rotation center line 33 is perpendicular to a line perpendicular to the planes of the two plate spectral crystals 31 and 32 (perpendicular to the paper surface). Further, the multicapillary X-ray lens (not shown) and the first and second flat plate crystal crystals 31, so that the parallel X-rays 34 emitted from the multicapillary X-ray lens are substantially incident on the rotation center line 33. 32 positional relationships are set in advance.

  By adopting such a configuration, as shown in FIGS. 3A and 3B, even if both the plate crystal crystals 31 and 32 rotate as a whole, the main X spectrally separated by the plate crystal crystals 31 and 32 is obtained. The line 35 always exits the second flat plate spectral crystal 32 in parallel with the incident X-ray 34 regardless of the spectral wavelength. Therefore, the X-ray detector 36 can always detect the outgoing X-ray 35 only by linearly moving in the direction perpendicular to the incident X-ray 34.

  In this embodiment, as shown in FIG. 3, the first flat plate crystal 31 on the incident side may be short, but the second flat plate crystal 32 on the output side has a large rotation of the first flat plate crystal 31. However, it is desirable to keep the length of the X-ray reflected so that it can be always received.

  Further, in the case where two flat plate crystal crystals are always fixed as in this embodiment, so-called channel cut two crystals (FIG. 4) cut out from one large block of crystal crystals are used for these. Also good.

  As a second embodiment of the X-ray spectroscopic apparatus of the present invention, the first flat plate spectral crystal and the second flat plate spectral crystal are connected by a parallelogram link, and can move relative to each other while maintaining a parallel state. A configuration example will be described. In this example, as shown in FIGS. 5A and 5B, a rhombic ABCD having an optical path of X-rays 54 (incident X-rays) emitted from a multicapillary X-ray lens as one side is formed, and the first flat plate The spectroscopic crystal 51 is arranged so that the center of the surface coincides with the vertex A and the surface is parallel to the diagonal line AC. The second flat plate spectral crystal 52 is arranged so that the center of the surface coincides with the apex B, and the surface is parallel to the surface of the first flat plate spectral crystal 51. In this state, the first flat plate spectral crystal 51 and the second flat plate spectral crystal 52 are connected by the parallelogram link AEFD. The length of AE (= DF) is arbitrary. The first flat plate spectral crystal 51 is rotatable around the point A.

  With such a configuration, as shown in FIGS. 5A and 5B, even if the first flat plate spectral crystal 51 rotates and the second flat plate spectral crystal 52 moves according to the parallelogram link AEFD. The main X-rays 55 dispersed by the flat plate spectral crystals 51 and 52 are always emitted from the second flat plate spectral crystal 52 in parallel with the incident X-rays 54 regardless of the spectral wavelength. Therefore, the X-ray detector 56 can always detect the outgoing X-ray 55 only by linearly moving in the direction perpendicular to the incident X-ray 54.

  As a third embodiment of the X-ray spectrometer of the present invention, a configuration example in which the first and second flat plate spectral crystals are driven by mechatronics will be described. In this example, as shown in FIG. 6, the first driving unit 61a for rotating the first flat plate spectral crystal 61 to rotate it and the second driving unit 62a for rotating and moving the second flat plate spectral crystal 62 to it. Are respectively controlled by the control unit 67 together with the third drive unit 66a for moving the X-ray detector 66. The control unit 67 reflects and spectrally reflects the X-rays reflected and dispersed by the first flat plate spectral crystal 61 while the first and second flat plate spectral crystals 61 and 62 maintain a parallel relationship with each other. Then, the second flat plate spectral crystal 62 is rotated and moved. As a result, as in the above embodiments, the X-ray detector 66 can always detect the spectrally separated X-rays by simply moving in the vertical direction in FIG.

  In the configuration of this embodiment, since the second flat plate spectral crystal 62 can be rotated and moved with a higher degree of freedom, the position of the X-ray detector 66 is fixed and the X plate reflected by the second flat plate spectral crystal 62 is reflected. It is also possible to move the second flat plate crystal 62 so that the line always enters the X-ray detector 66.

  In any of the above configurations, a solar slit 68 can be provided immediately before the X-ray detector 66 as shown in FIG.

1 is a schematic configuration diagram of a conventional X-ray spectrometer using a curved spectral crystal. 1 is a schematic configuration diagram of a conventional X-ray spectrometer using a multicapillary and a flat plate crystal. 1 is a schematic configuration diagram of a two-crystal fixed X-ray spectrometer that is a first embodiment of the present invention. The top view (a) and side view (b) of the channel cut bicrystal which can be used with the spectrometer of 1st Example. The schematic block diagram of the parallelogram link type | mold X-ray-spectrometer which is 2nd Example of this invention. The schematic block diagram of the mechatronics type | mold X-ray spectrometer which is 3rd Example of this invention.

Explanation of symbols

31, 51, 61... First flat plate spectral crystal 32, 52, 62... Second flat plate spectral crystal 33, 53... Rotation center line 34, 54. 56, 66... X-ray detector 61a... First driving unit 62a for rotating the first flat plate spectral crystal 62a. Second driving unit 66a for rotating and moving the second flat plate spectral crystal. ... Control unit 68 ... Solar slit

Claims (4)

An X-ray spectrometer that wavelength-disperses X-rays emitted from a minute region that can be regarded as a point on a sample,
A multicapillary X-ray lens having a point focal point on the incident end face side facing the sample and emitting substantially parallel light on the exit end face side;
A first flat plate spectral crystal disposed on the outgoing X-ray optical path of the multicapillary X-ray lens;
A second flat plate spectral crystal having the same lattice constant as that of the first flat plate spectral crystal and disposed parallel to the first flat plate spectral crystal on the optical path of the X-ray reflected by the first flat plate spectral crystal;
A driving mechanism for rotating the first flat plate spectral crystal around the X-ray irradiation surface and moving the second flat plate spectral crystal while maintaining a parallel relation to the first flat plate spectral crystal;
An X-ray spectroscopic apparatus comprising:   2. The X-ray spectrometer according to claim 1, wherein in the driving mechanism, the first flat plate spectral crystal and the second flat plate spectral crystal are fixed in parallel with each other.   The X-ray spectrometer according to claim 2, wherein the second flat plate spectral crystal is formed longer than the first flat plate spectral crystal. The X-ray spectrometer according to claim 1, wherein in the driving mechanism, the first flat plate spectral crystal and the second flat plate spectral crystal are connected by a parallelogram link.

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