JPH0714960Y2 - X-ray spectrometer - Google Patents

Description

[Detailed Description of Device] a. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal straight advance type X-ray spectrometer.

B. 2. Description of the Related Art A crystal linear X-ray spectroscope used in an electron beam microanalyzer or the like has a positional relationship between both the entrance and exit slits and the spectroscopic crystal depending on the type of spectroscopic element (spectroscopy crystal or diffraction grating) and curvature used. The structure is mechanically connected so as to maintain a certain relationship, and it is impossible to exchange and use spectroscopic elements having different curvatures. A relatively small Rowland diameter spectroscope using a dispersive crystal is used for X-ray spectroscopy in the short wavelength range, but a long wavelength X-ray spectroscope for light element analysis uses a diffraction grating as a spectroscopic element. It is a device with a large Roland diameter, and it is not possible to cover a wide wavelength range with one spectroscope, and a plurality of X-ray spectroscopes with different Roland circle diameters are arranged around the sample. .

C. DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention aims to extend the wavelength range that can be covered by one device by enabling wavelength scanning using spectroscopic elements with different curvatures with one spectroscope. To do.

D. Means for Solving the Problems In an X-ray spectroscope, a spectroscopic element driving device that moves a spectroscopic element straight, and an integrated unit of an X-ray emission slit of the spectroscope and a detector are independently moved in the X-axis direction and the Y-axis direction. An X, Y drive device, a regulating means for regulating the directions of the spectroscopic element and the X-ray emission slit, and a plurality of spectroscopic elements having different Rowland circle diameters are arranged on a predetermined diameter about a predetermined rotation axis, and these are arranged. Exchange means for exchanging a spectroscopic element having a different Rowland circle diameter by rotationally driving, and the spectroscopic element, the X-ray emission slit, and the detection according to the detection wavelength on the Roland circle corresponding to the curvature of the exchanged spectroscopic element. Drive for giving instructions to the spectroscopic element driving device, the X, Y driving device, and the regulating means so as to drive and control the position of the integrated body of the vessel and the directions of the spectroscopic element and the X-ray emission slit. And a device.

E. The wavelength driving mechanism of the spectroscopic element needs to be changed depending on the type of spectroscopic element or the curvature of the spectroscopic element.
The rotation position and installation position of the spectroscopic element can be controlled by a sliding device that is slidable in the detection direction of the excitation line and equipped with a rotation drive device for the spectroscopic element at the tip, and the exit slit and the detector are integrated. Equipped with a device that controls movement of the rotation drive device that controls rotation with an XY drive device to an arbitrary position.Based on the spectroscopic element used for analysis, the arrangement of the spectroscopic element and detector corresponding to each wavelength position is obtained in advance by a computer. Remember
The wavelength scanning is to be performed based on the stored data.

Regarding the arrangement of the spectroscopic element and detection corresponding to each wavelength position, either a method by function calculation or a method of creating a control table of each control element corresponding to the wavelength position may be used. By preparing a plurality of correspondence tables, it becomes possible to perform wavelength scanning according to each dispersive crystal with one driving device.

F. Embodiment FIG. 1 shows an embodiment of the present invention. In FIG. 1, S
Is a sample, and 1 is a spectroscopic element that disperses X-rays emitted from a sample S excited by an electron beam. 2 is exit slit, 3 is X
The X-ray transmitted through the slit 2 is detected by the line detector. Reference numeral 5 is an L for driving the spectroscopic element 1 in the arrow L direction (wavelength scanning direction).
It is a direction drive device. M1 is a pulse motor that drives the L-direction drive device 5. M2 is a pulse motor that rotates the spectroscopic element 1 around the center line (spectral center) passing through the center of the spectroscopic element and along the surface of the spectroscopic element. Reference numeral 6 denotes a holding table that integrally holds the slit 2 and the detector 3, which is attached to the deceleration shaft of the motor M5, and the incident direction is controlled by the motor M5. The motor M5 is mounted on a table 6 which is held on a Y drive shaft 7 so as to be movable in the Y direction, and is driven by the motor M4 in the Y axis direction. Both ends of the Y drive shaft 7 are movably connected to the X drive shaft 8. The X drive shaft 8 is connected to the motor M3, and the Y drive shaft 7 is moved in the X direction by the rotation of the motor M3. The drive shaft is a screw shaft and is screwed and connected to the female screw of the connecting portion, and the connecting portion moves along the drive shaft due to the rotation of the drive shaft. Further, two X drive shafts 8 are provided perpendicularly to the Y drive shaft 7. The two X drive shafts 8 are connected by a timing belt (not shown) so as to rotate in the same direction at the same time, or the motor M3 is used. By connecting the connecting part of the drive shaft rotated by the screw connection and connecting with the other drive shaft by slidable fitting connection, and by making either one of the connecting parts longer in the axial direction, the Y-axis X drive shaft 7
The structure is such that the drive direction is not displaced when the Y drive shaft 7 is driven in the direction, and the axial direction of the Y drive shaft 7 deviates from the Y direction. That is,
The spectroscopic element 1 is controlled by the motor M1 in the L direction and the incident angle θ ₁ is controlled by M2, and the slit 2 and the detector 3 are controlled by the motor M3.
Driven in the X direction by the motor M4 in the Y direction, an arbitrary trajectory can be drawn in the plane of the drawing, and the detection direction is controlled by the motor M5. It can be set. The control device 4 stores, as a table, the orientations of the spectroscopic elements corresponding to the respective wavelength positions of the spectroscopic elements and the positions and the orientations of the slits 2 of the motors M1 to M5 depending on the type of the spectroscopic element 1, and stores them in a table. The rotation position of each motor M1 to M5 corresponding to the wavelength position is read from the table by inputting the type of, and the control of each motor M1 to M5 is performed so that the slit, the spectroscopic element, and the detector are positioned at the wavelength position by wavelength scanning. To do.

When the X-rays emitted from the sample S are separated by a dispersive crystal,
As shown in FIG. 3, the electron beam irradiation point O, the spectral center Q of the dispersive crystal 1, the exit slit 2 central point K, and the curvature center O ″ of the dispersive crystal 1 are located on one circumference (Roland circle R). In addition, the spectroscopic element 1 and the slit 2 (including the detector 3) must be moved so that the incident angle and the outgoing angle have the same value. M5 must be controlled, so the positions of the spectroscopic element 1 and the slit 2 with respect to the wavelength position are obtained in advance as follows and a wavelength correspondence table is created.

In FIG. 3, a circle W whose center is the irradiation point O and whose radius is the radius of curvature 2R of the spectroscopic element is drawn. Since the radiation angle is determined in the L direction, the incident angle θ ₁ = α with respect to the L direction. Draw a line from the O point at the angle of, find the intersection point P with the circle W, draw the circle R whose diameter is OP, and let the intersection point between the circle R and the straight line L be Q, and obtain the line QK with ∠OQK = 2α. Point K at the intersection with the pulling circle R
Then, Q becomes the spectral center of the spectroscopic element 1, and K becomes the center of the slit 2. When the spectroscopic element is moved along the straight line L, the locus of the position of the slit 2 determined in this way is a curve like C connecting the point d and the point O where the straight line L and the 45 ° straight line intersect the circle W, Using the variable t representing the center position of the dispersive crystal on the straight line L and the radius of curvature 2R of the dispersive element as parameters,
It is expressed in the form of x = f (t, R) and y = g (t, R). f
Although the mathematical expression of (t) and g (t) is complicated, the relationship table between t and x, y can be created in advance for the curvatures of some spectroscopic elements used. The values of t on the table are discontinuous, but by setting the interpolation calculation program in the CPU, x, x
y can be determined. The positional relationship between the spectroscopic element 1 and the slit 2 is obtained by the above method.

FIG. 2 shows an example in which the spectroscopic element is replaced with another spectroscopic element having a different Roland circle diameter, and a plurality of spectroscopic elements 1, 1'are arranged on the spectroscopic element installation base 10 symmetrical with respect to the rotation axis of the switching motor M6. When the motor holding stand 9 for mounting the switching motor M6 is connected to the wavelength drive motor M2 so that the spectral center of the spectroscopic element coincides with the axial center of the wavelength drive motor M2,
By rotating the switching motor M6, the spectral centers of the respective spectral elements can be set at the rotational centers of the wavelength drive motor M2, which eliminates the need to replace the spectral elements, which is more efficient.

G. Effect of the Invention Conventionally, when using spectrometers with different Rowland circle diameters, the equipment configuration was such that multiple spectrometers with different Rowland circles were placed around the sample, so the utilization rate was low for one spectrometer. Although it is uneconomical, according to the present invention, one spectroscope can be used as a spectroscope for different Roland circles, so that the operating rate is improved and the price / function value of the device is significantly improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a configuration diagram of a spectroscope driving device of the second embodiment, and FIG. 3 is an explanatory diagram of arrangement of a spectroscopic element and a detector. S ... Sample, M1-M5 ... Pulse motor, 1 ... Spectroscopic element, 2 ... Slit, 3 ... Detector, 4 ... Control device,
5 ... L-direction drive device, 6 ... holding base, 7 ... Y drive shaft, 8 ... X drive shaft.

Claims (1)

[Scope of utility model registration request] 1. A spectroscopic element driving device for linearly moving a spectroscopic element, an X, Y driving device for independently moving an X-ray emission slit of a spectroscope and a detector independently in the X-axis direction and the Y-axis direction, and a spectroscopic device. A restricting means for restricting the direction of the element and the X-ray emission slit, and a plurality of spectroscopic elements having different Rowland circle diameters are arranged on a predetermined diameter around a predetermined rotation axis, and these are rotationally driven to rotate the Rowland circle diameter. Exchange means for exchanging a different spectroscopic element, a position of the spectroscopic element, an integrated unit of the X-ray emission slit and the detector according to the detection wavelength on the Rowland circle corresponding to the curvature of the exchanged spectroscopic element, and It is characterized by comprising: the spectroscopic element drive device, the X, Y drive device, and a drive control device for giving an instruction to the regulating means so as to drive and control the directions of the spectroscopic element and the X-ray emission slit. X-ray spectrometer.