JP4041606B2 - X-ray analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray analyzer used for examining, for example, an element contained in a sample, its amount, and its distribution state.
[0002]
[Prior art]
The X-ray analyzer, for example, irradiates a sample placed on a sample stage with X-rays, detects fluorescent X-rays or transmitted X-rays generated at that time with a detector, and appropriately detects the detection output. By processing, the constituent elements and internal structure of the sample are analyzed .
[0003]
Incidentally, when performing predetermined analysis using the X-ray analyzer, before irradiating the X-ray to the sample, it is necessary to preliminarily identify (point to be irradiated with X-rays) measurement point in the sample. Conventionally, as shown in FIG. 4, the sample 52 is observed by an optical microscope or a CCD camera 54 from a direction different from the X-ray (primary X-ray) 53 irradiated on the sample 52 placed on the sample stage 51. The measurement location is indicated by a laser pointer (not shown), or a cross marker (not shown) is superimposed on the obtained image. In FIG. 4, 55 is an X-ray generator, 56 is an X-ray conduit that guides the X-ray 53 in the direction of the sample, and 57 is a fluorescent X-ray 58 generated by irradiation of the sample 52 with the primary X-ray 53. A fluorescent X-ray detector to be detected, 59 is a lens, and 60 is a light guide that guides visible light applied to the sample 52.
[0004]
[Problems to be solved by the invention]
However, the conventional method has the following disadvantages. That is, if the sample 52 is large, for example, 100 mm square or more, the whole cannot be grasped as an image, and it takes time to find a measurement location. In addition, if the lens 59 is made interchangeable or a smooth lens is used to make it easier to search, the optical axis is shifted and the cost is increased.
[0005]
In the conventional method, the irradiation direction of the primary X-ray 53 on the sample 52 and the optical observation direction of the sample 52 are different, so that if the height of the sample 52 on the sample stage 51 changes, the optical image The irradiation position of the X-ray inside changes.
[0006]
In addition, it is necessary to perform illumination for observing the sample 52. In that case, a window material 57a on the front surface of the fluorescent X-ray detector 57 that does not transmit visible light, such as a Be (beryllium) film, is used. It is necessary to use it. However, the window material 57a that does not transmit visible light generally has a low transmittance of low-energy X-rays. Therefore, detection sensitivity of elements lighter than Si, such as Na, Mg, and Al, is low.
[0007]
The present invention has been made in consideration of the above-mentioned matters. The purpose of the present invention is to quickly and accurately confirm the X-ray irradiation spot on the sample, to perform efficient measurement, and to detect light elements. The object is to provide an X-ray analyzer capable of measuring well.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention , the sample is analyzed by detecting fluorescent X-rays and / or transmitted X-rays generated when X-rays are irradiated on the sample placed on the sample stage. In the X-ray analysis apparatus configured to perform , a direction connecting the sample stage between a sample placement position for placing the sample on the sample stage and an X-ray irradiation position where X-ray irradiation is performed and as having a configured sample transfer stage so as to be movable respectively in height direction of the direction as well as the sample perpendicular to its direction both above the sample transfer stage, the sample stage position and X A line image sensor that captures an optical image of the entire sample in synchronism with the transfer from the sample mounting position of the sample stage on which the sample is placed to the X-ray irradiation position is provided in the middle of the transfer path between the irradiation position and the ray irradiation position . And this line image Captures the optical image of the entire sample captured by capacitors as image data, the image data on a display screen on a computer display is provided as a sample image, the position to be measured from the displayed sample images on the display screen Is provided with a controller for controlling the movement of the sample transfer stage in the three directions so that the position on the sample corresponding to the designated position becomes the X-ray irradiation position. .
[0009]
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show one embodiment of the present invention, FIG. 1 is a diagram schematically showing the overall configuration of the X-ray analyzer of the present invention, and FIG. 2 is the X-ray analyzer. FIG. 3 is a diagram schematically illustrating a planar configuration of the sample transfer stage, and FIG.
[0011]
First, in FIG. 1, reference numeral 1 denotes a main body block of an X-ray analyzer, which is made of, for example, brass, and an X-ray generator 3 that houses an X-ray tube 2 and the like is provided thereabove. Reference numeral 4 denotes a seal portion interposed between the main body block 1 and the X-ray generator 3. Reference numeral 5 denotes a space in the main body block 1, and an X-ray conduit 6 for guiding the primary X-rays a emitted by the X-ray generator 3 with an appropriate beam diameter is provided in the internal space 5 in the vertical direction. It has been. Reference numeral 7 denotes an X-ray shielding wall connected to the lower part of the main body block 1, which is made of, for example, stainless steel or lead glass, and below the inner space 5 is a thin diaphragm 8 made of, for example, an X-ray transparent material such as polyethylene resin. A sample chamber 9 partitioned by is formed. Reference numeral 10 denotes a sample chamber entrance for sample insertion / removal formed on the upper surface of the front side (left side in the figure) of the X-ray shielding wall 7 and includes an open / close door 11 that rotates in the vertical direction.
[0012]
Reference numeral 12 denotes a sample stage on which the sample 13 is placed. Although details of the sample stage 12 will be described later, the sample stage 12 is arranged in the X direction (perpendicular to the paper surface in FIG. 1), which is the width direction of the sample room 9, as shown in FIG. Direction), the Y direction (left-right direction in FIG. 1) which is the depth direction of the sample chamber 9, and the Z direction (up-down direction in FIG. 1) which is the height direction of the sample chamber 9, respectively. Hereinafter, the sample transfer stage 14 for holding and transferring the sample stage 12 in a predetermined state will be described in detail.
[0013]
First, 15 is a base member having a rectangular shape in plan view, for example, which is provided from the front side (sample chamber inlet 10 side) to the rear side (right side in FIG. 1) so as to be long in the Y direction. Is held by the vertical drive mechanism 16 so that it can move in the vertical direction (Z direction).
[0014]
Reference numerals 17 and 18 denote side plates that are erected on both sides in the longitudinal direction of the base member 15, and screw members 19 and guide members 20 and 21 are pivotally supported or held on these side plates 17 and 18. That is, the screw member 19 is provided on one side in the X direction of the base member 15 over substantially the entire length in the Y direction, and is coupled to the stepping motor 22 that rotates in both the forward and reverse directions. In addition, the guide members 20 and 21 are provided on both sides in the X direction of the base member 15 over almost the entire length in the Y direction.
[0015]
Reference numeral 23 denotes a sample stage holder that holds the sample stage 12 and moves it in the Y direction along the guide members 19 and 20. The sample stage holder has a rectangular shape in plan view and is screwed to the screw member 19 on one end side in the X direction. A bracket member 24 having a nut member (not shown) and a guided portion (not shown) that is guided while being held by the guide member 20 is provided, and is held by the guide member 21 on the other end side in the X direction. A bracket portion 25 having a guided portion (not shown) to be guided is provided.
[0016]
Reference numerals 26 and 27 denote side plates standing on both sides in the X direction of the sample stage holder 23, and screw members 28 and guide members 29 and 30 are pivotally supported or held on these side plates 26 and 27. That is, the screw member 28 is provided on one side in the Y direction of the sample stage holder 23 over almost the entire length in the X direction, and is coupled to the stepping motor 31 that rotates in both the forward and reverse directions. . In addition, the guide members 29 and 30 are provided on both sides in the Y direction of the sample stage holder 23 over almost the entire length in the X direction.
[0017]
The sample table 12 is rectangular in plan view, for example, so that the sample 13 can be held horizontally on the upper surface thereof, and a nut member (not shown) that is screwed to the screw member 28 on one end side in the Y direction. And a bracket portion 32 having a guided portion (not shown) that is guided while being held by the guide member 29, and being guided while being held by the guide member 30 on the other end side in the Y direction. A bracket portion 33 having a guide portion (not shown) is provided.
[0018]
In the sample transfer stage 14 having the above-described configuration, by operating the stepping motor 22, the sample stage holder 23 is moved to a position on the sample chamber inlet 10 side (hereinafter referred to as a sample placement position) and directly below the X-ray conduit 6. The stepping motor 31 can be operated when the sample stage holder 23 is at the X-ray irradiation position while being movable in the Y direction connecting with the irradiation position of the primary X-ray a (hereinafter referred to as the X-ray irradiation position). Thus, the sample stage 12 can be moved in the X direction.
[0019]
In the sample transfer stage 14, the fluorescent X-ray b and the transmitted X-ray c generated when the sample 13 on the sample stage 12 is irradiated with the primary X-ray a are not shielded or attenuated. Needless to say, each member is constructed and assembled.
[0020]
In FIG. 1 again, reference numeral 33 denotes, for example, a semiconductor detector for detecting the fluorescent X-ray b generated in the sample 13 when the sample 13 on the sample stage 12 located at the X-ray irradiation position is irradiated with the primary X-ray a. This fluorescent X-ray detector is provided at the tip of a housing 35 connected to a tank 34 containing a cooling medium. Reference numeral 36 denotes a transmission X-ray detector that detects a transmission X-ray c transmitted through the sample 13 when the sample 13 is irradiated with the primary X-ray a, and is provided below the sample transfer stage 14.
[0021]
1 to 3, reference numeral 37 denotes a line image sensor provided above the sample transfer stage 14, more specifically, in the middle of the conveyance path between the sample placement position and the X-ray irradiation position. 12 is provided at a height position that does not come into contact with the sample 13 on the sample stage 12 along the X direction orthogonal to the Y direction in which the 12 moves. The line image sensor 37 has a length at least equal to the length of the sample table 12 in the X direction. As this line image sensor 37, a commercially available one (210 mm in length) can be suitably used.
[0022]
In FIG. 1, 38 is a controller for controlling the X-ray generator 3 , 39 is a controller for controlling the vertical drive mechanism 16 and the stepping motors 22 and 31 of the sample transfer stage 14, and 40 is a signal with the controllers 38 and 39. It is a data processing unit that exchanges and outputs predetermined control signals to these, and processes detection output of the fluorescent X-ray detector 33 and the transmission X-ray detector 36. Reference numeral 41 denotes a computer that performs overall control of the entire apparatus. The computer 41 includes, for example, a personal computer. The computer 41 exchanges signals with the data processing unit 40 and inputs reading contents of the line image sensor 37. The personal computer 41 is connected to a color display 42 as an output device and a keyboard 43 and a mouse 44 as input devices.
[0023]
The operation of the X-ray analysis apparatus having the above configuration will be described with reference to FIG. 3. The internal space 5 is set to 0.1 Torr or less, for example, and the sample chamber 9 is set to atmospheric pressure. The open / close door 11 is opened, and the sample 13 is inserted into the sample chamber 9 from the sample chamber inlet 10 and placed on the sample stage 12 at the sample placement position. Then, the vertical drive mechanism 16 is operated to adjust the height of the base member 15 so that the sample 13 does not come into contact with the ceiling portion of the sample chamber 9 during movement, and then the door 11 is closed.
[0024]
The stepping motor 22 is rotated in a predetermined direction, and the sample stage holder 23 at the sample placement position is moved in the X-ray irradiation position direction . By this movement , the sample 13 placed on the sample table 12 on the sample table holder 23 passes through the lower part of the line image sensor 37 and is transferred by the line image sensor 37. Captured synchronously. When the sample 13 reaches the X-ray irradiation position, an optical image of the entire sample 13 is taken into the personal computer 41, and an image 45 of the sample 13 is displayed on the screen 42a of the color display 42.
[0025]
Therefore, the person in charge of measurement (or the operator) searches the sample image 45 on the display screen 42a by enlarging the part to be measured, and designates the measurement position with the mouse 44, for example. The sample stage holder 23 is moved so that the position on the sample 13 corresponding to the position designated on the screen 42a is located at the point where the primary X-ray a is irradiated. This movement is performed by appropriately operating the stepping motors 22 and 31. In this state, the desired measurement can be performed by irradiating the primary X-ray a from the X-ray generator 3 .
[0026]
In the X-ray analyzer, an optical image of the entire sample is captured as image data into the personal computer 41 while the sample stage 12 on which the sample 13 is placed is transferred from the sample placement position to the X-ray irradiation position. Therefore, by specifying the position in the sample image 45 on the display screen 42a of the personal computer 41 without searching for the measurement position again, the measurement location on the sample 13 can be easily identified and confirmed .
[0027]
Since the optical image of the sample 13 is captured by the line image sensor 37, it is not affected by lens aberration, and the positional accuracy is better than that using a lens like a CCD camera.
[0028]
Further, during the measurement, since illumination for observing the sample is unnecessary, the inside of the sample chamber 9 is shielded from the outside, so that light shielding is necessary as a window material of the fluorescent X-ray detector 33, but Be ( A window material (for example, resin) having a higher transmittance of low energy X-rays than a beryllium film can be used, and so-called light element detection sensitivity is improved.
[0029]
The present invention is not limited to the above-described embodiment. For example, it is not always necessary to partition the internal space 5 and the sample chamber 9 with the thin diaphragm 8. When the thin diaphragm 8 is not provided, it is necessary to make the internal space 5 and the sample chamber 9 high vacuum each time measurement is performed.
[0030]
In place of the stepping motors 22 and 31 in the sample transfer stage 14, other motors such as a servo motor with an encoder may be used. Further, the data processing unit 40 may be provided in the personal computer 41.
[0031]
【The invention's effect】
As described above, in the present invention, the optical image of the entire sample is taken into the computer by the line image sensor in synchronization with the transfer from the sample placement position of the sample stage on which the sample is placed to the X-ray irradiation position . Since the image data is displayed as the sample image on the display screen, the X-ray irradiation location on the sample can be easily and efficiently confirmed.
[0032]
In addition, by specifying the position to be measured from the sample image displayed on the display screen , the sample transfer stage is placed so that the measurement position in the sample corresponding to the specified position becomes the X-ray irradiation position. Even in the case of samples with different heights , movement control is performed in three directions: the direction connecting the mounting position and the X-ray irradiation position, the direction orthogonal to the direction, and the height direction of the sample. The X-ray irradiation location can be set quickly and accurately, and efficient measurement can be performed. Light elements can also be measured with high sensitivity.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an overall configuration of an X-ray analyzer according to the present invention.
FIG. 2 is a diagram schematically showing a planar configuration of a sample transfer stage of the X-ray analyzer.
FIG. 3 is an operation explanatory diagram.
FIG. 4 is an explanatory diagram of a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Sample stand, 13 ... Sample, 14 ... Sample transfer stage, 37 ... Line image sensor, 39 ... Movement control controller, 41 ... Computer, 42a ... Display screen, a ... X-ray , b ... X-ray fluorescence, c ... Transmission X-ray .

Claims (1)

In an X-ray analyzer configured to detect a fluorescent X-ray and / or transmitted X-ray generated when X-rays are irradiated on a sample placed on a sample stage and analyze the sample , the direction and the sample perpendicular to the sample stage, the direction and the direction connecting between the X-ray irradiation position where the irradiation of the sample stage position and X-ray for mounting a sample on a sample stage is carried out both as having the configured sample transfer stages in the height direction so as to be movable respectively, above the sample transfer stage, during transfer path between said sample stage position and the X-ray irradiation position a sample line image sensor for capturing an optical image of the entire sample in synchronization with the transfer from the sample mounting position of the sample stage of mounting the X-ray irradiation position is provided, and is taken up by the line image sensor Light of the whole sample Captures the image as image data, the image data on a display screen on a computer display is provided as a sample image by specifying the to be measured positions from the display screen the displayed sample images, is the designated An X-ray analyzer comprising: a controller for controlling movement of the sample transfer stage in the three directions so that a position in the sample corresponding to the position becomes an X-ray irradiation position .

Images