JPH03165300A - X-ray spectroscope inspecting device - Google Patents

Abstract

PURPOSE:To detect the twist of a holding base of a spectroscopic crystal and the deviation of the kinetic locus of an outlet slit from the ideal locus by determining the condensing position of the light emitted from a light emitting element from the output signal of a line sensor. CONSTITUTION:The center of curvature 0 of a cylindrical mirror 2 having the curved surface, the radius of which is the diameter of a Rowland circle, the reference position P of the line sensor and the position Q of the outlet slit exist on the circumference of the Rowland circle R and an arc P0=arc Q0 is obtd. from a disposition relation when the cylindrical mirror 2 is disposed and a light emitting element 4 is disposed behind the outlet slit 3 and further, the reference position of the line sensor 1 is disposed in the position to be irradiated with X-rays. The incident light from the light emitting element 4 on a scanner A from the output slit position Q is, therefore, reflected by the cylindrical mirror 2 and is condensed to the reference position P of the line sensor 1. The adjustment of the spectral crystal angle and position of the scanner A, the position adjustment of the outlet slit 3 and the inspection of the positional deviation of the outlet slit 3 in the entire scanning wavelength region are easily executed in this way.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an X-ray spectrometer inspection device.

[Conventional technology]

BACKGROUND ART A concentrated wavelength scanning X-ray spectrometer (hereinafter referred to as a scanner) using a curved crystal as a spectroscopic element is used in an X-ray microanalyzer (EPMA), a fluorescent X-ray analyzer, and the like. This scanner has an X-ray scanner entrance point P, a cylindrical curved spectroscopy crystal 2', and a position Q of the X-ray exit slit, with the diameter being the radius of curvature of the spectroscopy crystal, as shown in The center 0' is on the center normal of the spectroscopic crystal 2', and the spectroscopic crystal 2' is positioned symmetrically with the normal line 00'' of the spectroscopic crystal as the center on a circle (Rowland circle) passing through the surface center 0'' of the spectroscopic crystal. The structure is such that ffQ is driven by the exit slit. Even if the driving accuracy of the scanner is high, the angle and position of the spectroscopic crystal and the position of the exit slit must be properly positioned at all scanning wavelengths, that is, the X-rays must be arranged so that they are focused on the exit slit. Furthermore, even if the angle and position of the spectroscopic crystal are adjusted according to a certain wavelength so as to focus the light on the exit slit, if the wavelength is different from the adjusted wavelength, the focusing position may be slightly shifted from the exit slit. Although this is a problem with the spectroscopic crystal itself, it is necessary to correct the position of the exit slit for each spectral wavelength so that the X-rays are focused on the exit slit for each spectral wavelength. For this purpose, the spectral accuracy of the scanner is inspected and adjusted.
To inspect and adjust the scanner using X-rays while the scanner is in the air, you can either prepare a large number of vacuum-sealed XH tubes with minute focuses that generate X-rays of the desired wavelength, or switch the wavelength to obtain the desired wavelength. A vacuum-sealed X-ray tube with a minute focus that can generate X-rays of the same wavelength must be prepared. Since this is very effective, a method has been adopted in which the EPMA itself is used as an X-ray generator. Therefore, after the scanner is attached to the device, the inside of the device is evacuated and then the inspection is performed. Therefore, in order to perform the above inspection and adjustment, while adjusting the angle and position of the spectroscopic crystal and the position of the exit slit,
Since it is necessary to measure the signal intensity from the detector, it requires 4 to 10 hours of work time, so there is a problem in that it takes a long time to inspect and adjust the scanner.

[Problem to be solved by the invention]

An object of the present invention is to make it possible to easily adjust the angle and position of the spectroscopic crystal of a scanner, adjust the position of the exit slit, and inspect the positional deviation of the exit slit in the entire scanning wavelength range.

[Means to solve the problem]

In a wavelength-scanning X-ray spectrometer using a curved crystal, a means for inputting light to either the X-ray incident point or the X-ray exit point on the Rowland circle of the spectrometer is arranged, and the above-mentioned X A cylindrical mirror whose radius is the diameter of the Rowland circle of the line spectrometer and whose center of curvature is on the Rowland circle is installed, and the center is placed on the Rowland circle of the spectrometer at the X-ray emission point or incidence point that corresponds to the incident point of the light. A line sensor capable of detecting the amount of incident light and having positional resolution is arranged as a line sensor, and a means for calculating the center point of the incident light from the output signal of the line sensor is provided, and the center point of the incident light is calculated for each wavelength position of the X-ray spectrometer. 6 with a means to output points

[For use]

The present invention aims to enable the spectral characteristics of the scanner to be inspected and adjusted in the atmosphere by taking out the scanner from a measuring device such as an X-ray microanalyzer, and installing the scanner in a dark room or dark box where optical measurements can be performed. In a scanner installed in a dark room or dark box, a cylindrical mirror with a curved surface whose radius is the diameter of the Roland circle is used instead of the spectroscopic crystal, a light emitting element is placed behind the exit slit, and a line is placed at the X-ray irradiation position. When the reference position of the sensor is arranged, as shown in FIG. From arc PO = arc QO
Therefore, the light from the light emitting element that enters the scanner from the output loss slit position IFQ is reflected by the cylinder M2 and focused on the reference position P of the line sensor. This optical path follows the opposite path in the scanner, where the X-rays are separated from the X-ray incident point by the spectroscopic crystal and reach the exit slit, and the optical path taken by the inspection mechanism using a cylindrical mirror follows the opposite path. The arrangement of the measuring mechanism using the spectroscopic crystal can be examined by investigating whether the spectroscopic crystal passes through the . Therefore, the present invention uses the above-mentioned inspection mechanism to calculate the condensing position of the light emitted from the light emitting element from the detection results of the light intensity distribution on the line sensor. The deviation of the motion trajectory of the slit from the ideal trajectory can be determined. Since light is used instead of X-rays, -
Since there is no need to evacuate the vacuum chamber every time, the spectroscopic crystal and exit slit of the scanner can be easily moved in a short time. It goes without saying that the positional relationship between the light source and the light receiving element may be reversed.

【Example】

FIG. 1 shows an embodiment of the present invention.
is a line sensor placed at the place where the sample is set during measurement, and has 600 12 μm square photosensitive areas arranged in a row at a 14 μm pitch on a silicon substrate.
It is installed next to the wL adjustment machine. 2 is a circle l! whose radius is the diameter of the Rowland circle of the scanner and whose center of curvature is on the Rowland circle. The li mirror is held in a spectroscopic crystal holding part (not shown). 3 is an exit slit, and 4 is a light emitting element (LED) arranged behind the exit slit 3. During measurement, an X-ray detector is placed in place of the light emitting element 4. The cylindrical mirror 2, exit slit 3 and ED4 are
It is identified on the mechanism that performs wavelength scanning drive under two consecutive constant conditions, and constitutes the scanner A. Scanner A +, t
It is removed from a measurement device such as an X-ray microanalyzer and placed in the atmosphere in a dark room or dark box (not shown) where optical measurements can be made, and then installed in the measurement device after the spectral characteristics have been inspected and adjusted. It will be done. The scanner A uses a cylindrical mirror 2 and an exit slit 3 by driving a wavelength scanning motor 5.
L) ED 4 is the predetermined spectral wavelength ff1s1.52
Moved to s3. 6 is a driver and wavelength scanning motor 5
control. Reference numeral 7 denotes an interface that appropriately converts detection signals and control signals so that communication between the microcomputer 10 and each connection element can be properly performed. Reference numeral 8 denotes an A/D converter that converts the output signal of the line sensor 1 into digital data. Reference numeral 69 denotes a bit converter that controls the positions of the output signal of the line sensor 1. The microcomputer 10 receives the light intensity (P) and bit position (
X value) is stored as set data, and a light intensity distribution diagram as shown in Figure P1 is displayed. By statistically processing the data of the light intensity distribution map P1 with the microcomputer 10 and finding the X value at the center of gravity of the light intensity distribution, ± which is the required accuracy of the scanner is obtained.
The position Xc of the light source image can be determined with an accuracy of about 3 μm. Next, the wavelength scanning motor 5 is driven to wavelength scan the scanner A, the position Xc of the light source image with respect to the wavelength λ is measured, and a functional relation diagram (P2) between the light source image position and the wavelength is created. This functional relationship diagram between the light source image position and wavelength shows the positional shift of the focal point in wavelength scanning, so
It can be used not only to check scanner accuracy but also to analyze the cause of scanner failure. In the above embodiment, the line sensor is placed at the X-ray entrance point of the scanner, and the light source is placed behind the X-ray exit slit of the scanner, but even if this arrangement is reversed, the same effect as in the above embodiment can be obtained.

【effect】

According to the present invention, the angle and position of the spectroscopic crystal and the position of the exit slit, which determine the spectral accuracy of the scanner, can be optically inspected in all wavelength ranges, so scanner adjustment and accuracy inspection can be performed without vacuum work. This makes it possible to quickly and easily measure the angle and position adjustment of the scanner's spectroscopic crystal and the positional deviation of the exit slit over the entire wavelength scan range, as well as to inspect the accuracy of the scanner and identify the causes of scanner defects. Analysis has also become easier.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of the optical path of the above embodiment, and FIG. 3 is an explanatory diagram of the optical path of the scanner. 1... Line sensor, 2... Cylindrical mirror, 3... Exit slit, 4... LED, 5... Wavelength scanning motor, 6...
...Driver, 7...Interface, 8...
A, D converter 9...Bit converter, 10...Microcomputer, A...Scanner, SL, S2. S3...Scanner wavelength scanning position, Pl...Light intensity distribution diagram, P2.
...Functional relationship diagram between light source image position and wavelength.

Claims (1)

[Claims] In a wavelength-scanning X-ray spectrometer using a curved crystal, a means for inputting light to either the X-ray incident point or the X-ray exit point on the Rowland circle of the spectrometer is arranged, and the above-mentioned X A cylindrical mirror whose radius is the diameter of the Rowland circle of the line spectrometer and whose center of curvature is on the Rowland circle is installed, and the center is placed on the Rowland circle of the spectrometer at the X-ray emission point or incidence point that corresponds to the incident point of the light. A line sensor capable of detecting the amount of incident light and having positional resolution is arranged as a line sensor, and a means for calculating the center point of the incident light from the output signal of the line sensor is provided, and the center point of the incident light is calculated for each wavelength position of the X-ray spectrometer. An X-ray spectrometer inspection mechanism characterized by being provided with means for outputting a point.