JP2012088094A - X-ray diffraction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diffraction device which has exceedingly high resolution and also can acquire an X-ray diffraction image with high intensity, by enabling both cylindrical surface conversion processing and time delay integration processing to be performed in the same arithmetic control process.SOLUTION: An X-ray diffraction device 1 is constituted by installing a signal processing unit 21 comprised of a DSP (digital signal processor) on the outside of a computer comprised of a CPU 17, a memory 20 and the like. A measuring device 2 performs X-ray diffraction measurement. A two-dimensional pixel type detector 12 transmits a large data amount of two-dimensional diffraction data output from a plurality of pixels to the signal processing unit 21 via a camera link cable 24 of a high speed communication line. The signal processing unit 21 performs cylindrical surface conversion processing 26 and time delay integration processing 27 on the large amount of transmitted diffraction data, and transmits image data of a processing result to a bus 23 by each line data.

Description

  The present invention relates to an X-ray diffractometer that detects and measures diffracted X-rays emitted from a sample by a pixel-type X-ray detector in which a plurality of pixels are arranged.

  Conventionally, when scanning is performed using a flat two-dimensional detector, there are several methods of adding the outputs of adjacent detection elements at regular time intervals. For example, as one of them, the charge accumulated using the electrical characteristics of the CCD used in a two-dimensional detector using a CCD (Charge Coupled Device) is transferred to an adjacent device. (For example, refer to Patent Document 1).

  As another method, there is a method of calculating a count value by a digital circuit or a computer as performed by a detector using a photocounting element such as Si (silicon) (for example, see Patent Document 2).

  Any of these has the advantage that the sensitivity (that is, the count value per unit time) is improved as compared to a point detector such as a scintillation counter when used for measuring an X-ray diffraction pattern. On the other hand, there is a problem that the angular resolution is lowered.

  In order to solve the problem of a decrease in angular resolution, a technique of converting a flat plate image obtained from a detector into an image of a cylindrical surface is known (see, for example, Patent Document 3 and Patent Document 4). Cylindrical surface conversion is performed based on pixel data for one frame (one screen) obtained from the detector, but data for one frame obtained for each scan of the detector is integrated for each pixel. Such an integration method is generally called time delay integration (TDI).

  In order to realize cylindrical surface conversion and time delay integration, conventionally, an image obtained from a detector is sent directly to a computer and processed by software of the computer. However, in this method, since the amount of data received by the computer per unit time becomes enormous, there is a problem that the measurement speed decreases.

JP 2005-241509 A JP 2010-038722 A JP 2007-101247 A JP 2007-322384 A

  The present invention has been made in view of the above-mentioned problems in the conventional apparatus. In the X-ray diffractometer, it is possible to measure by reducing the amount of data received by the computer per unit time while preventing the decrease of the angle. The purpose is to prevent a decrease in speed.

  In general, the X-ray diffractometer according to the present invention is provided with a dedicated high-speed arithmetic circuit between a detector and a computer, where cylindrical surface conversion and time delay integration are performed, and the result is transferred to the computer. The above objective is achieved.

Specifically, the first X-ray diffractometer according to the present invention is:
(1) an X-ray source that generates X-rays irradiated on the sample;
(2) having a plurality of pixels arranged two-dimensionally, receiving X-rays emitted from the sample by those pixels, and outputting a received light amount as a signal for each pixel; An X-ray detector arranged at a predetermined camera length;
(3) Move at least one of the X-ray source, the sample, and the X-ray detector in the equator plane, and set an angle of the X-ray source with respect to the sample and an angle of the X-ray detector with respect to the sample. A goniometer to measure angles,
(4) an arithmetic control unit that controls the operation of the goniometer so that the X-ray detector can detect the X-rays emitted from the X-ray source and diffracted by the sample;
(5) Connected to the arithmetic control unit via the first communication line, receives the output signal of the X-ray detector via the second communication line, performs signal processing, and outputs the processed signal to the first communication line. A signal processing unit that transmits to the arithmetic control unit through a communication line,
(6) The signal processing unit
(A) Cylindrical surface conversion processing for mapping each of a plurality of one-frame image data obtained on the X-ray detector surface of the X-ray detector, which is a plane, onto a cylindrical surface having the radius of the camera;
(A) a time delay integration process for integrating a plurality of one-frame image data after the cylindrical surface conversion process while shifting each other by one pixel each;
A process of transmitting the two-dimensional data after the time delay integration process to the first communication line for each row data in the meridian direction that is a direction orthogonal to the equatorial plane is performed.

The second X-ray diffractometer according to the present invention is
(1) an X-ray source that generates X-rays irradiated on the sample;
(2) having a plurality of pixels arranged one-dimensionally, receiving X-rays emitted from the sample by those pixels, and outputting a received light amount as a signal for each pixel; An X-ray detector arranged at a predetermined camera length;
(3) Move at least one of the X-ray source, the sample, and the X-ray detector in the equator plane, and set an angle of the X-ray source with respect to the sample and an angle of the X-ray detector with respect to the sample. A goniometer to measure angles,
(4) an arithmetic control unit that controls the operation of the goniometer so that the X-ray detector can detect the X-rays emitted from the X-ray source and diffracted by the sample;
(5) Connected to the arithmetic control means via the first communication line, receives the output signal of the X-ray detector via the second communication line, performs signal processing, and outputs the processed signal to the first communication line. A signal processing unit that transmits to the arithmetic control unit through a communication line,
(6) The signal processing unit
(A) Cylindrical surface conversion processing for mapping each of a plurality of one-line image data obtained on the X-ray receiving surface of the X-ray detector, which is a plane, to a cylindrical surface having the radius of the camera length;
(A) a time delay integration process for integrating a plurality of one-line image data after the cylindrical surface conversion process while shifting each other by one pixel each;
(C) An X-ray diffractometer that performs processing for transmitting one-dimensional data after time delay integration processing to the communication line pixel by pixel.

  According to the first and second X-ray diffraction apparatuses, the signal processing unit is connected to the calculation control unit via the first communication line. That is, the signal processing unit is provided independently of the arithmetic control unit. The arithmetic control unit is a control unit responsible for controlling the operation of the goniometer and other devices. Usually, in addition to the control for the operation of the goniometer, etc., both the cylindrical surface conversion process and the time delay integration process are performed by the arithmetic control unit. It has been extremely difficult to perform the above because of the data processing capability. This is because the cylindrical surface conversion process and the time delay integration process must process a very large amount of data.

  In the present invention, a signal processing unit is independently provided outside the arithmetic control unit responsible for controlling the operation of the goniometer, etc., and cylindrical signal conversion processing and time delay integration processing are performed by the signal processing unit. Each line data of the line is transmitted to the calculation control unit. Therefore, processing that requires a large amount of data processing such as cylindrical surface conversion processing and time delay integration processing is performed without incurring a calculation delay by the calculation control unit included in the control computer for the goniometer or the like. Became possible. Since the time delay integration process can be performed in addition to the cylindrical surface conversion process, diffraction line data with high resolution and high intensity can be obtained.

  In the X-ray diffractometer according to the present invention, a signal for one frame accumulated in the plurality of pixels within a predetermined X-ray exposure time is sent from the X-ray detector to the signal processing unit. It is desirable to transmit in bulk via In this way, signal transmission from the X-ray detector to the signal processing unit can be smoothly performed in a short time.

In the X-ray diffractometer according to the present invention, the first communication line is preferably a communication line formed by connecting an internal bus of a computer or an internal bus of a computer and a communication line for a computer.
The computer communication line is, for example, a communication cable conforming to each protocol of TCP / IP, USB, and IEEE, or other network communication cable. Internal buses and communication lines for computers are high-performance communication lines themselves, but they must take charge of control of goniometers and other equipment. In addition to this control, cylindrical surface conversion processing and time delay integration processing It is very difficult to handle such a large amount of data. However, in the present invention, the cylindrical surface conversion process and the time delay integration process are performed by the signal processing unit, and the signal is transmitted to the first communication line after reducing the data amount. Therefore, even if a computer communication line or a computer internal bus is connected to the subsequent stage of the signal processing unit, there is no delay in signal transmission.

  In the X-ray diffraction apparatus according to the present invention, the second communication line is preferably a high-speed data communication line. The high-speed data communication line is, for example, a camera link cable that is a cable conforming to the camera link standard, or a communication cable having a data transmission capability equivalent to or higher than that of the camera link cable.

  The camera link is a standard for connecting a digital camera and an image recording device. The camera link is a communication standard specialized in transmitting digital signals at high speed, and is a communication system based on asynchronous serial transmission including a clock signal, for example. By using the communication form using this camera link, a large amount of data output from the X-ray detector (that is, a large amount of pixel data before cylindrical surface conversion processing and before time delay integration) can be reliably ensured within a short time. It can be transmitted to the signal processor.

  According to the first and second X-ray diffraction apparatuses according to the present invention, the signal processing unit is connected to the calculation control unit via the first communication line. That is, the signal processing unit is provided independently of the arithmetic control unit. The arithmetic control unit is a control unit responsible for controlling the operation of the goniometer and other devices. Usually, in addition to the control for the operation of the goniometer, etc., both the cylindrical surface conversion process and the time delay integration process are performed by the arithmetic control unit. It has been extremely difficult to perform the above because of the data processing capability. This is because the cylindrical surface conversion process and the time delay integration process must process a very large amount of data.

  In the present invention, a signal processing unit is independently provided outside the arithmetic control unit responsible for controlling the operation of the goniometer, etc., and cylindrical signal conversion processing and time delay integration processing are performed by the signal processing unit. Each line data of the line is transmitted to the calculation control unit. For this reason, it is possible to perform processing requiring a large amount of data processing such as cylindrical surface conversion processing and time delay integration processing without any problem without incurring a calculation delay by the calculation control unit. Since the time delay integration process can be performed in addition to the cylindrical surface conversion process, diffraction line data with high resolution and high intensity can be obtained.

1 is a block diagram showing an embodiment of an X-ray diffraction apparatus according to the present invention. It is a perspective view which shows the measuring apparatus which is the principal part of the X-ray-diffraction apparatus of FIG. It is a flowchart which shows the process performed by the control system of FIG. It is a figure which shows typically the mode of the mapping from the cylindrical surface to a plane in cylindrical surface conversion. It is a figure which shows typically the mode of distribution of the count value from the plane to a cylindrical surface in cylindrical surface conversion. It is a projection figure when the mode of the movement of the position at the time of cylindrical surface conversion is seen from the X-ray incident direction. It is a figure which shows the mode of distribution of the count value accompanying the movement of the pixel in cylindrical surface conversion. It is a figure which shows the movement distance of the point in cylindrical surface conversion. It is a figure which shows typically the mode of the image after cylindrical surface conversion. It is a figure which shows typically a mode that the image after cylindrical surface conversion is packed and stored within 1 frame (1 screen). It is a figure which shows typically the number of pixels which move in cylindrical surface conversion, and the distribution rate of a count value. It is a figure which shows typically the procedure of the integration of the image data in a time delay integration process. It is a perspective view which shows other embodiment of the measuring apparatus used with the X-ray-diffraction apparatus which concerns on this invention. It is a block diagram which shows other embodiment of the X-ray-diffraction apparatus which concerns on this invention. It is a block diagram which shows other embodiment of the X-ray-diffraction apparatus which concerns on this invention.

  Hereinafter, an X-ray diffraction apparatus 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 is a block diagram showing an embodiment of an X-ray diffraction apparatus according to the present invention. The X-ray diffractometer 1 includes a measuring device 2 that is a portion that performs a mechanical operation to realize measurement, and a control unit 3 that is a portion that controls the operation of the measuring device 2.

  For example, as shown in FIG. 2, the measuring device 2 includes a goniometer 4 that is a goniometer and a sample support device 5. The sample support device 5 supports the sample 7 to be measured at a sample support position that is a predetermined position. The sample 7 is a powder sample in this embodiment. The goniometer 4 supports an X-ray tube 9 by an incident side arm 8. The goniometer 4 also supports a two-dimensional pixel type detector 12 by a light receiving side arm 11. In FIG. 2, the sample support device 5 and the goniometer 4 are schematically shown instead of specific shapes.

  The incident side arm 8 is rotatable about an axis ω extending through the X-ray receiving surface (the upper surface in FIG. 2) of the sample 7. Hereinafter, this rotation is referred to as θ rotation. On the other hand, the light receiving side arm 11 can also rotate around the same axis ω. Hereinafter, this rotation is referred to as 2θ rotation. The incident side arm 8 and the light receiving side arm 11 can rotate independently of each other.

  An X-ray focal point 13 that is an X-ray source is provided inside the X-ray tube 9. The X-ray focal point 13 is formed on an anti-cathode arranged to face the cathode such as a filament. Specifically, the region where the electrons emitted from the filament collide with the surface of the counter cathode is the X-ray focal point 13. In the present embodiment, the counter-cathode is a rotating counter-cathode, the X-ray collision surface of the counter-cathode is formed of Cu (copper), and X-rays including CuKα rays are emitted from the X-ray focal point 13. To do.

  Usually, the X-ray focal point 13 is an elongated linear region, and the X-ray extracted from the longitudinal side of the X-ray focal point 13 to the outside of the X-ray tube 9 is an X-ray whose cross-sectional shape is a linear shape. It is called X-ray. On the other hand, the X-ray extracted from the short side of the X-ray focal point 13 to the outside of the X-ray tube 9 is an X-ray having a rectangular or almost circular cross section, and is called a point focus X-ray. In this embodiment, as shown in the figure, line focus X-rays are extracted.

  The two-dimensional pixel type detector 12 has a plurality of pixels (pixels) 14 arranged in a matrix in a plane, and a circuit board 15 provided on the back surface thereof. Each pixel 14 receives X-rays and generates an electrical signal corresponding to the amount of received light. The pixel 14 is a photocounting type pixel formed using, for example, a semiconductor. The circuit board 15 includes amplification elements connected to the pixels 14 in a matrix. As described above, the two-dimensional pixel type detector 12 transmits the X-ray intensity signals generated individually for the plurality of pixels 14 individually to the outside simultaneously. The number of pixels 12 can be freely set according to the type of measurement. In the present embodiment, it is assumed that vertical × horizontal = 512 × 512.

  The two-dimensional X-ray detector 12 can use any detector as long as the detector can detect X-rays for each pixel and output a signal for each pixel. For example, the two-dimensional pixel type detector 12 disclosed in JP-A-6-342098, JP-A-9-090048, JP-A 2010-038722, etc., a CCD image sensor, a C-MOS image sensor A two-dimensional pixel type detector such as can be used.

  By rotating the incident side arm 8 of the goniometer 4 by θ around the ω axis, the incident angle θ of the X-ray that exits the X-ray focal point 13 and enters the sample 7 can be changed. Further, the angle θ1 at which the central pixel of the two-dimensional pixel detector 12 looks at the central portion of the sample 7 can be changed by rotating the light receiving side arm 11 about the ω axis by 2θ. The angle θ1 at which the two-dimensional pixel type detector 12 looks at the sample 7 is an angle at which the central pixel of the pixel type detector 12 takes in the diffracted X-rays emitted from the sample 7 at the diffraction angle θ1.

  While the X-ray diffraction measurement is performed, the X-ray incident angle θ on the sample 7 is changed continuously or intermittently at a desired rotation speed. The goniometer 4 changes the X-ray incident angle θ in such a manner, and controls the diffraction line capture angle θ1 by the pixel detector 12 to always change to be the same as the X-ray incident angle θ. Therefore, the diffraction line capture angle 2θ of the pixel detector 12 with respect to the X-ray incident angle θ (that is, the line connecting the center of the pixel detector 12 and the center of the sample 7 is the center line of the X-ray incident on the sample 7). The angle formed by the extension is always maintained at twice the X-ray incident angle θ. That is, the pixel X-ray detector 12 continuously or intermittently in the opposite direction at the same angular velocity as the X-ray focal point 13 around the ω axis so as to maintain an angle twice as large as the X-ray incident angle θ. Moved by.

  The control unit 3 includes, for example, a CPU (Central Processing Unit) 17, a ROM (Read Only Memory) 18, a RAM (Random Access Memory) 19, a memory 20, and a signal processing unit 21. These elements are connected to each other by an internal bus 23 as a first communication line. In the internal bus 23, the instruction bus and the data bus may be common, or they may be different from each other. The electrical control system of the measuring apparatus 2 shown in FIG. 2 is connected to the internal bus 23 via the input / output interface 29. A display device 22 such as a display or a printer is connected to the internal bus 23 via an input / output interface 29.

  The output terminal of the pixel type detector 12 in the measuring device 2 is connected to the input terminal of the signal processing unit 21 by a high-speed communication line as a second communication line, for example, a camera link cable 24. The camera link is an asynchronous input / output interface with a simple communication protocol, and is a communication method capable of transmitting data at high speed because it is simple. This camera link is, for example, a communication method using a 24-bit serial signal including a clock signal at the head, and is a method for synchronizing with the head clock signal.

  The signal processing unit 21 includes a digital signal processor (DSP) that is a microprocessor specialized in digital signal processing, a microcomputer, a signal processing circuit having a hardware configuration, and the like. In this embodiment, Vertex 6 (trade name), which is a DSP manufactured by XILINX, is used. The DSP 21 has a memory 25 inside, and in accordance with the program software stored in the memory 25, two processes are performed according to the program software, in this embodiment, a cylindrical surface conversion process 26 and a time delay integration process 27. It has become. These processes will be described later. The memory 25 includes a storage area for storing data after processing by the cylindrical surface conversion processing 26 and the time delay integration processing 27.

  The memory 20 in the control unit 3 stores a diffraction measurement program 30 that is program software for realizing X-ray diffraction measurement using the measurement apparatus 2 shown in FIG. 2 and raw data obtained by the measurement. A data storage area 31 is provided. The diffraction measurement program 30 also includes an analysis program for realizing various analyzes based on raw data obtained by measurement. The data storage area 31 also includes an area for storing analysis data that is a result of analysis realized according to the analysis program.

  As shown in FIG. 3, the diffraction measurement program 30 includes a process for controlling the generation of X-rays (step S2), a process for controlling the operation of the goniometer (step S3), a process for managing the safety of the apparatus (step S4), Measurement such as a process of reading data from the signal processing unit 21 (step S5), a process of performing image processing on necessary data and displaying the data on a display, or printing with a printer (steps S7 and S8) Various processes for performing are performed.

Hereinafter, cylindrical surface conversion processing and time delay integration processing realized by the signal processing unit 21 shown in FIG. 1 will be described.
(Cylinder conversion method)
In FIG. 2, the plane including the center line R0 of the incident X-ray and perpendicular to the ω axis is the equator plane. A line L0 where the X-ray receiving surface of the pixel type detector 12 intersects the equator plane is an equator line on the detector. A line L1 orthogonal to the equator line L0 is a meridian. The distance N1 from the ω axis that is the center of rotation to the meridian L1 of the pixel-type detector 12 is the camera length.

  The process of mapping the image obtained by the two-dimensional pixel type detector 12 which is a plane onto the cylindrical surface M0 which is in contact with the detection surface at the meridian L1 and whose radius is equal to the camera length N1 is cylindrical surface conversion processing. The image obtained by the conversion is required to be the same as that obtained by a detector in which pixels having the same size as the actual detector are arranged on a cylindrical surface. FIG. 4 shows a state in which the detection surface of the detector 12 and the cylindrical surface M0 in FIG. 2 are viewed from the direction of arrow A (an arrow extending from the meridian L1). As shown in FIG. 4, X-rays irradiated onto an area corresponding to one pixel on the cylindrical surface M0 spread on a plane and are irradiated to a plurality of pixels. The numbers are different. For this reason, it is impossible to strictly obtain a two-dimensional image on the cylindrical surface M0.

  For the cylindrical surface conversion, a memory area (reference numeral 25 in FIG. 1) having the same number of cells as the number of pixel elements and having an initial value of 0 (zero) is prepared. Then, the count value obtained by the pixel is distributed to and around the memory cell at the position corresponding to the position (see FIG. 5) where the X-ray irradiated to the center of the pixel passes through the cylindrical surface M0. A cylindrical surface conversion process is realized.

(Distribution method)
When the cylindrical surface conversion is performed, as shown in FIG. 6, the point P1 on the plane is mapped to the point Q1 on the cylindrical surface. Since the moving distance of the point is independent of the size of the pixel, not all the count values are distributed to a specific pixel on the cylindrical surface, but are distributed to four neighboring pixels as shown in FIG. It will be. The distribution ratio to those pixels is calculated from the distance of movement of the points.

(Point moving distance)
FIG. 8A and FIG. 8B show the relationship between the point P1 on the plane and the point Q1 on the cylindrical surface when the camera length N1 is “R”. “A” indicates the distance in the equator direction of the point P1 from the direct beam position P0 of the detector, and “b” indicates the distance in the meridian direction of the point P1 from the direct beam position P0. “R” indicates the length of the arc on the cylindrical surface from the direct beam position P0 to the point Q1.

であることから、赤道方向の移動距離をΔＬとすると、
ΔＬ＝ａ−ｒ
＝ａ−ＲΔ２θ ……（２）
である。 By converting the image to a cylindrical surface, the point P1 is
In the equator direction, a-r
In the meridian direction, Δb
Just move. The relationship between these moving distances and the coordinates of the point P1 and the camera length R is

Therefore, if the movement distance in the equator direction is ΔL,
ΔL = ar
= A-RΔ2θ (2)
It is.

となる。 Further, the movement distance Δb in the meridian direction is

It becomes.

(Converted image)
When the cylindrical surface conversion is performed, the image obtained from the detector is deformed as shown in FIG. Therefore, when the time delay integration process is performed in the next processing step, if the same addition is performed as in the case where the cylindrical surface conversion is not performed, a correct image cannot be obtained. Therefore, as shown in FIG. 10, the memory area for storing the converted image is packed in the reverse direction of the scan, the length in the meridian direction is the same as the original image, and the width is narrowed by the conversion and correct addition is performed. An image is created by filling in 0 (zero) in a portion where the result of (1) is not obtained. At this time, if the number of pixels in the equator direction necessary to store the image shortened by the conversion is Lt, one column of image data in the time delay integration process is created by adding Lt images.

(Determining where to allocate the count value)
In the cylindrical surface conversion, the count value of the two-dimensional image obtained from the detector is distributed to the memory area for the cylindrical surface. At this time, to which memory cell the count value is distributed is determined by the moving distance of the pixel by the conversion. On the other hand, since the converted image is stored in the reverse direction of the scan of the memory area, the determination of the cell to which the count value is allocated is performed in consideration thereof.

Now, the number of pixels in the equator direction of the detector is “M”, the number of pixels in the meridian direction is “N”, and the pixel and pixel coordinates are determined as shown in FIG. Also, the coordinates of the position where the direct beam is irradiated

_{(M c + ε m, n} c + ε n) 0 ≦ ε m, ε n ≦ 1

If the pixel size is “s”, the center is the coordinate on the plane.

(M + 0.5, n + 0.5)

If the amount of movement of the pixel in the cylindrical surface transformation is considered in the pixel coordinate system, from equations (2) and (3),

となる。ここで、関数floor(x)を、ｘを超えない整数を返すものと定義すると、この画素の計数値を配分する先の画素の（隅の）座標は、円筒面上では、

It becomes. Here, if the function floor (x) is defined as returning an integer not exceeding x, the coordinates of the pixel to which the count value of this pixel is allocated are (on the cylindrical surface)

で得られるｍ_ｒ，ｎ_ｒを使って、

Using m _r and n _r obtained from

(M _r , n _r )
(M _r + 1, n _r )
(M _r , n _r +1)
(M _r +1, n _r +1)
It can be expressed as. The length Lt of the cylindrical surface in the equator direction is

となる。

It becomes.

移動する画素数と計数値の配分率は図１１のようになる。これらの式を全てのｍについて事前に計算し表にしておけば、赤道方向の移動距離に関してはその表から直接求めることができる。また、同じことをｎについて行えば子午線方向の移動距離も表から求めることができる。しかしながら、それを行うと表があまりにも大きくなるため、本実施形態での円筒面変換は、

（ｎ_ｃ＋ε_ｎ−ｎ−０．５），（１−ｃｏｓΔ２θ）

のみの表を作成しておき、子午線方向の移動距離に関しては変換の実行時にその表の値とｎの値から、画素の移動先と計数値の配分率を計算する。 (Counting rate distribution)
When the decimal part of the amount of movement of the pixel accompanying the conversion represented by the equations (4) and (5) is defined as follows,

The number of moving pixels and the distribution ratio of the count values are as shown in FIG. If these equations are calculated and tabulated in advance for all m, the movement distance in the equator direction can be directly obtained from the table. Moreover, if the same thing is done about n, the movement distance of a meridian direction can also be calculated | required from a table | surface. However, when doing so, the table becomes too large, so the cylindrical surface transformation in this embodiment is

( _Nc + [epsilon] _n- n-0.5), (1-cos [Delta] 2 [theta])

As for the movement distance in the meridian direction, the pixel movement destination and the distribution ratio of the count value are calculated from the value of the table and the value of n for the movement distance in the meridian direction.

(Time delay integration processing)
In the present embodiment picture, two-dimensional image data for one frame, that is, one screen is collectively output from the pixel-type detector 12 of FIG. 2 every predetermined time, for example, every 5 ms. The image data for one frame is subjected to the cylindrical surface conversion process. As a result, as schematically shown in FIG. 12, a plurality of image data D that has undergone the cylindrical surface conversion processing is stored in the memory 25 of FIG.

  The time delay integration processing unit 27 integrates the data in each pixel while shifting the image data D for one frame after the cylindrical surface conversion by one pixel. Thereby, diffracted X-ray intensity data having the same diffraction angle 2θ is integrated, that is, added or accumulated, and as a result, it is possible to obtain diffraction line data having a high intensity. The image data after the time delay integration processing is sent out from the signal processing unit 21 to the bus 23 for each row data (data corresponding to reference numeral 32 in FIG. 12) in accordance with a command from the CPU 17 and transmitted to the RAM 19 or the memory 20. Remembered.

  The computer of FIG. 1 used in the present embodiment is a computer constituted by a CPU 17, a bus 23, and the like. This computer is responsible for various types of arithmetic control shown in FIG. 3, and directly processing image data consisting of a large amount of data sent out from the pixel type detector 12 is based on the data processing structure or the data transfer structure. It is extremely difficult in view of the restrictions.

  However, in this embodiment, a signal processing unit 21 configured by a DSP is provided outside the computer, and the signal processing unit 21 receives image data with a large amount of data and performs both cylindrical surface conversion processing and time delay integration processing. Thus, only one line of image data is sequentially transmitted from the signal processing unit 21 to the computer. For this reason, the computer can process the image data from the pixel-type detector 12 at high speed without any trouble after performing the arithmetic control of FIG. 3, and if necessary, performs image processing in step S7 of FIG. Visual display can be performed by the display device 22 of FIG. 1, for example, a display or a printer.

  As described above, in this embodiment, the signal processing unit 21 is provided outside the computer that is the arithmetic control unit, and the image processing unit 21 is responsible for image data with a large amount of data, and the computer has an image with a small amount of data. Since data is transmitted, both cylindrical conversion processing and time delay integration processing, which are processing in which the amount of data to be processed becomes very large, can be realized using a computer.

  And, by realizing both cylindrical surface conversion processing and time delay integration processing, it was possible to obtain diffraction line data with extremely high resolution and high intensity in X-ray powder diffraction measurement.

  In the present embodiment, necessary information such as an angle measurement range and an angle measurement speed is sent to the goniometer 4 from the computer to the firmware. The firmware that has received the information drives the goniometer 4 according to the instruction. The two-dimensional pixel type detector 12 installed in the goniometer 4 transmits the acquired X-ray intensity data to the computer via the signal processing unit 21.

  In addition to the goniometer 4, the computer sends an instruction to an X-ray generator including the X-ray tube 9 and other devices. Further, the computer receives information from the security mechanism and, in some cases, performs data processing in parallel with the measurement during the measurement. Therefore, the computer used in this embodiment is a high-performance computer, and is a computer that performs multi-faceted arithmetic control simultaneously. Even if the computer of this embodiment is high-performance, since multi-faceted control and analysis are performed at the same time, applying a higher load will slow down the movement of the computer and affect the speed of measurement, etc. .

  On the other hand, cylindrical surface conversion is indispensable to maintain high angular resolution. If the cylindrical surface conversion is not performed, the data is blurred and broad. In the case of performing cylindrical surface conversion, conventionally, it has been necessary to send all data for one frame to a control computer for a goniometer or the like and process it by the computer.

  However, in order to increase the measurement speed and improve the angular resolution, it is necessary to send a large amount of data for a plurality of frames from the detector, and such a large amount of data is required on a normal net (that is, a signal line). Therefore, the measurement speed could not be increased.

  In this embodiment, for example, assuming that the number of pixels is 512 × 512, the amount of data is 4 bytes per pixel, and the measurement is performed at a measurement interval of 5 ms, the transfer speed is about 210 Mbytes / second. At present, the speed of a LAN (Local Area Network) that is normally used is 100 base. Even in the latest 1000base standard, the effective speed is actually considered to be about 200 Mbytes / second. This is because of the hardware and TCP / IP protocol problems, and the application layer actually has only a fraction of the speed. Therefore, it is impossible to transmit a large amount of data such as 210 Mbytes / second through the current communication line.

  In the conventional X-ray diffractometer, unless the problem of the communication speed as described above is solved, it is impossible to perform the measurement with the cylindrical surface converted and the speed increased in order to obtain blur-free data. .

  In this embodiment, the amount of data sent to the computer is reduced by performing cylindrical surface conversion processing on the detector side and using a time delay integration technique for a plurality of one-frame data after the cylindrical surface conversion processing. It became possible. As a result, a huge amount of X-ray intensity data output from the detector can be processed without any trouble by a conventionally used computer.

  In this embodiment, the above-described communication speed problem for a huge amount of data is solved by connecting the detector 12 and the signal processing unit 21 with a camera link cable 24 capable of high-speed communication. It can be considered that the relationship between the communication speeds can be fundamentally solved by connecting all of the detector 12 and the computer with the camera link cable 24. However, the camera link standard has a limitation on the length of the cable to be used. For this reason, it is impossible in reality to connect everything between the detector 12 and the computer with the camera link cable 24.

  In this regard, in the present embodiment, a signal processing unit 21 is provided between the detector 12 and the computer, and X-ray intensity data having an enormous amount of data is transmitted to the signal processing unit 21 through the camera link cable 24 to perform signal processing. The data amount is reduced by the unit 21 and the data is transmitted to the computer. For this reason, the signal line connecting the signal processing unit 21 and the computer can be used without any trouble by using a conventional communication line such as a LAN. According to the conventional communication line, the length limitation is not a problem.

(Other embodiment 1)
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.

  For example, in the above-described embodiment, the photo counting type two-dimensional pixel X-ray detector 12 in which a plurality of pixels formed of a semiconductor are arranged in both the vertical direction and the horizontal direction is used. As shown in FIG. 13, a one-dimensional pixel type detector 33 in which a plurality of pixels 14 are linearly arranged along the 2θ rotation direction can also be used.

  Even when this one-dimensional pixel type detector 33 is used, a cylindrical surface conversion process for obtaining a mapping on the cylindrical surface M0 is performed, and a plurality of one-frame image data after the cylindrical surface conversion process is processed for one pixel. Both time delay integration processing for integrating pixel data while shifting is performed.

  When the two-dimensional pixel type detector 12 shown in FIG. 2 is used, image data is transmitted for each row data 32 from the signal processing unit 21 of FIG. 1 as schematically shown in FIG. When the one-dimensional pixel type detector 33 shown in FIG. 13 is used, data transmission is performed for each piece of pixel data instead of row data.

(Other embodiment 2)
In the embodiment of FIG. 1, the signal processing unit 21 is stored inside the control unit 3 configured by a computer. That is, the signal processing unit 21 is connected to the CPU 17 that is an arithmetic processing unit through the internal bus 23. Instead, as shown in FIG.
(1) The signal processing unit 21 is arranged outside the control unit 3,
(2) The pixel type detector 12 and the signal processing unit 21 are connected by a high-speed data communication line such as a camera link cable 24,
(3) The signal processing unit 21 and the control unit 3 may be connected by a communication line formed by connecting the internal bus 23 and a LAN cable 28 that is a computer communication line. The LAN cable 28 is a communication cable that complies with a communication protocol such as TCP / IP, USB, IEEE1394, or the like.

  In this embodiment, a high-speed data communication line such as the camera link cable 24 functions as the second communication line, and a communication line formed by connecting the internal bus 23 and the LAN cable 28 that is a computer communication line is the first communication line. It functions as a communication line.

(Other embodiment 3)
Furthermore, as shown in FIG. 15, the pixel type detector 12 and the signal processing unit 21 are stored inside the detector 16, and the pixel type detector 12 and the signal processing unit 21 are connected at a high speed like a camera link cable 24. The data communication line may be connected, and the signal processing unit 21 and the control unit 3 may be connected by a communication line formed by connecting the LAN 28 and the internal bus 23. The LAN cable 28 is a communication cable conforming to a communication standard such as TCP / IP, USB, IEEE1394, or the like.

  Also in this embodiment, the high-speed data communication line such as the camera link cable 24 functions as the second communication line, and the communication line formed by connecting the internal bus 23 and the LAN cable 28 that is a computer communication line is the first communication line. It functions as a communication line.

1. 1. X-ray diffractometer, 2. measuring device; Control unit, 4. 4. Goniometer, 6. sample support device; Sample, 8. 8. incident side arm; X-ray tube, 11. 12. Light receiving side arm, 12.2D pixel type detector (X-ray detector), X-ray focal point, 14. A plurality of pixels, 15. Circuit board, 16. Detector, 20. Memory, 21. 21. signal processing unit Display device, 23. Internal bus, 24. Camera link cable, 25. Memory, 26. Cylindrical surface conversion processing unit, 27. Time delay integration processing section, 28. LAN, 32. Row data, 33.1 dimensional pixel-type detector, a. Equatorial distance, b. Distance in meridian direction; D. Image data, L0. Equatorial line, L1. Meridian, M0. Cylindrical surface, N1. Camera length, P0. Direct beam position, P1. Points on the plane, Q1. A point on the cylindrical surface, R0. The center line of incident X-rays, θ. X-ray incident angle, θ1. Detector expected angle (diffraction angle capture angle), ω. Axis of rotation

Claims (6)

An X-ray source for generating X-rays irradiated on the sample;
A plurality of pixels arranged two-dimensionally, receiving X-rays emitted from the sample by the pixels, outputting a received light amount as a signal for each pixel, and a predetermined camera for the sample An X-ray detector arranged in a length;
At least one of the X-ray source, the sample, and the X-ray detector is moved in the equator plane, and an angle of the X-ray source with respect to the sample and an angle of the X-ray detector with respect to the sample are measured. Goniometer,
An arithmetic control unit that controls the operation of the goniometer so that the X-ray detector can detect X-rays diffracted from the X-ray source and diffracted by the sample;
It is connected to the arithmetic control unit via a first communication line, receives the output signal of the X-ray detector via the second communication line, performs signal processing, and passes the processed signal through the first communication line. A signal processing unit that transmits to the arithmetic control unit,
The signal processing unit
Cylindrical surface conversion processing for mapping each of a plurality of one-frame image data obtained on the X-ray detector surface of the X-ray detector that is a plane onto a cylindrical surface having a radius of the camera length;
A time delay integration process for integrating a plurality of one-frame image data after the cylindrical surface conversion process while shifting each other by one pixel;
An X-ray diffractometer that performs processing for transmitting two-dimensional data after time delay integration processing to the first communication line for each row data in a meridian direction that is a direction orthogonal to the equator plane. An X-ray source for generating X-rays irradiated on the sample;
A plurality of pixels arranged one-dimensionally, receiving X-rays emitted from the sample by the pixels, outputting a received light amount as a signal for each pixel, and a predetermined camera for the sample An X-ray detector arranged in a length;
At least one of the X-ray source, the sample, and the X-ray detector is moved in the equator plane, and an angle of the X-ray source with respect to the sample and an angle of the X-ray detector with respect to the sample are measured. Goniometer,
An arithmetic control unit that controls the operation of the goniometer so that the X-ray detector can detect X-rays diffracted from the X-ray source and diffracted by the sample;
It is connected to the calculation control means via a first communication line, receives the output signal of the X-ray detector via the second communication line, performs signal processing, and passes the processed signal through the first communication line. A signal processing unit that transmits to the arithmetic control unit,
The signal processing unit
A cylindrical surface conversion process for mapping each of a plurality of one-line image data obtained on the X-ray detector surface of the X-ray detector, which is a plane, to a cylindrical surface having a radius of the camera length;
A time delay integration process for integrating a plurality of one-line image data after cylindrical surface conversion processing while shifting each other by one pixel each;
An X-ray diffractometer which performs processing for transmitting one-dimensional data after time delay integration processing to the communication line pixel by pixel.   A signal for one frame accumulated in each of the plurality of pixels within a predetermined X-ray exposure time is collectively transmitted from the X-ray detector to the signal processing unit via the second communication line. The X-ray diffraction apparatus according to claim 1, wherein the X-ray diffraction apparatus is characterized.   4. The communication line according to claim 1, wherein the first communication line is a communication line formed by connecting an internal bus of a computer or an internal bus of a computer and a communication line for a computer. X-ray diffractometer.   The X-ray diffraction apparatus according to claim 1, wherein the second communication line is a high-speed data communication line.   6. The X-ray diffraction apparatus according to claim 5, wherein the high-speed data communication line is a camera link cable that is a cable conforming to a camera link standard.

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