JPH05113415A - Controlling apparatus for x-ray spectroscope - Google Patents

Abstract

PURPOSE:To obtain means for improving the reliability of the measuring result for each kind of measurement by automatically and sequentially controlling one or both of the wavelength and the optical axis of X-rays thereby to eliminate the fear that the wavelength and the optical axis are shifted during the measurement in a controlling apparatus for an X-ray spectroscope utilizing the diffraction phenomenon of a crystal plate. CONSTITUTION:The title controlling apparatus is so constituted as to include an X-ray spectroscope 3 for dividing X-rays by the diffraction phenomenon of crystal plates 4, 5, a slit plate 7 with a slit set at the downstream of the X-ray spectroscope 3, an outgoing X-ray detector 8 provided at the upstream of the slit plate 7 the measure the intensity of the outgoing X-rays, an outgoing X-ray detector 10 provided at the downstream of the slit plate 7 to detect the intensity of the outgoing X-rays, and a controlling system 11 mutually connecting the spectroscope 3, an incoming X-ray detector 8 and outgoing X-ray detector 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a controller for an X-ray spectroscope utilizing the diffraction phenomenon of a crystal plate.

[0002]

2. Description of the Related Art Conventionally, in a measuring device or the like using X-rays, the X-ray spectroscope is controlled by adjusting the orientation of the crystals to form a spectroscopic X-ray.
Even if the optical axis and wavelength of the rays are set to desired values, the portion of the dispersive crystal plate irradiated with the X-rays becomes hot during the operation of the measuring device, so that the portion is thermally expanded and the dispersive crystal is dissipated. Since the plate is distorted, the optical axis of the X-ray may fluctuate, and it is always necessary to fine-tune the dispersive crystal to restore the optical axis. However, there was a problem that the wavelength of the X-rays would be shifted when it was returned to.

On the contrary, when the X-ray wavelength is continuously swept by changing the orientation of the X-ray spectroscope crystal plate, the X-ray irradiation position on the X-ray crystal plate changes for each wavelength. Therefore, there is also a problem that the optical axis changes due to thermal distortion of the dispersive crystal. Conventionally, the wavelength and the optical axis are manually adjusted, and it is extremely difficult to always adjust them. Therefore, the actual condition is to allow the deviation after the adjustment to some extent.

[0004]

However, in recent years,
Since it has become necessary to perform highly accurate measurement in semiconductor technology and the like, realization of means capable of automatically controlling the wavelength or optical axis of X-rays has been strongly desired. The present invention automatically and sequentially controls one or both of the X-ray wavelength and the optical axis to eliminate the risk of the X-ray wavelength and the optical axis being displaced during measurement, and The purpose is to provide means for improving reliability.

[0005]

In an X-ray spectroscope control device according to the present invention, an X-ray spectroscope that disperses X-rays by a diffraction phenomenon of a crystal plate, and is installed downstream of the X-ray spectroscope. A slit plate having a slit, an incident X-ray detector installed upstream of the slit plate for measuring the intensity of incident X-rays, and an outgoing X-ray detection installed downstream of the slit plate for measuring the intensity of outgoing X-rays. And a controller for connecting the X-ray spectroscope, the incident X-ray detector, and the outgoing X-ray detector to each other.

In the above case, at least one of the incident X-ray detector and the outgoing X-ray detector is connected to an ionization chamber, a semiconductor X-ray detector,
Alternatively, it can be a photoelectron detector. And
By the control system, the intensity of the emitted X-ray emitted from the slit plate is gradually increased so that the intensity of the emitted X-ray becomes constant or constant.
The optical axis of the line spectrometer can be controlled. and again,
X that can detect the wavelength of X-rays as an X-ray spectrometer
The X-ray detector is adopted, and the X-ray emitted by controlling the orientation of the crystal plate of the successive X-ray spectrometer by the detection signal of the X-ray detector.
The wavelength of the line and the optical axis can be controlled.

[0007]

When the X-ray emitted from the X-ray spectroscope that disperses the X-ray by the diffraction phenomenon of the crystal plate is shaped by passing through the slit of the slit plate as in the present invention,
The intensity of X-rays is measured by the X-ray detectors installed upstream and downstream of this slit plate, and the X-ray spectroscope is controlled by the measured values to adjust the optical axis. By removing the influence of thermal strain of the crystal, it is possible to always obtain X-rays of maximum intensity or constant intensity.

Further, by installing an X-ray photon energy detector in the apparatus and controlling the orientation of the crystal plate of the X-ray spectrometer by the measured value, the wavelength of X-ray can be kept constant. .. Further, by simultaneously adjusting the X-ray intensity and the optical axis of the X-ray, the intensity of the X-ray and the optical axis can be made constant at all times, and the reliability of various measurements using the X-ray is improved. can do.

[0009]

EXAMPLES Examples of the present invention will be described below.

(First Embodiment) FIG. 1 is an explanatory diagram of an X-ray spectroscope control apparatus according to the first embodiment of the present invention. In this figure, 1 is an electron storage ring, 2 is synchrotron radiation, 3 is an X-ray spectroscope, 4 is a first dispersive crystal plate, 5 is a second dispersive crystal plate, and 6 is X.
Line, 7 slit plate, 8 photon energy detector,
Reference numeral 9 is an excited X-ray, 10 is an ionization chamber, and 11 is a controller.

In the X-ray spectroscope control device of the present invention, the radiated light 2 including the electromagnetic waves having wavelengths from the X-rays to the ultraviolet rays radiated from the electron storage ring 1 is the first dispersive crystal plate of the X-ray spectroscope 3. 4 and the second dispersive crystal plate 5 to diffract and select a wavelength, and an X-ray 6 having a wavelength suitable for a specific measurement is extracted.

The wavelength-selected X-ray 6 is shaped into a cross section of an appropriate size by the slit of the variable slit plate 7 and becomes an excited X-ray 9. The excited X-rays 9 pass through an ionization chamber 10 installed downstream of the excited X-rays 9 and are emitted toward, for example, a sample to be measured for fluorescence analysis.

When the excited X-rays that have passed through the slits of the variable slit plate 8 pass through the ionization chamber 10, the gas in the ionization chamber 10 is ionized to generate a signal representing the intensity of the excited X-rays 9, and this signal is generated. Is guided to the controller 11, and controls the optical axis of the X-ray spectrometer 3 by the control signal output from the control signal 11,
The intensity of the emitted X-ray can be maintained at the maximum or constant.

In the vicinity of the slit of the variable slit plate 7, a photon energy detector 8 such as a semiconductor detector capable of detecting the photon energy of dispersed X-rays is installed, and the separated X-rays are separated. The photon energy of the line is always detected. Then, the controller 11 converts the photon energy into a wavelength and controls the first dispersive crystal plate 4 and the second dispersive crystal plate 5 of the X-ray spectroscope 3 to keep the X-ray wavelength constant.
Alternatively, the wavelength of X-ray can be swept according to the purpose of measurement. A photoelectron detector utilizing the photoelectron emission phenomenon can be used as the X-ray detector.

X passing through the slit of the variable slit plate 7
A method of controlling the optical axis of the line by the ionization chamber 10 will be specifically described in the following examples.

(Second Embodiment) FIG. 2 is an explanatory diagram of an X-ray spectroscope control apparatus according to a second embodiment of the present invention. In this figure, 21 is an ionization chamber, 22 is an incident side ionization chamber, 23 is an emission side ionization chamber, 24 is a variable slit plate, 25 is an incident X-ray, 26
Is output X-ray, 27 and 29 are amplifiers, 28 and 30 are V / F
A converter, 31 and a variable slit controller, 32 is an X-ray spectroscope, 33 is a photon energy detector, and 34 is a controller.

The configuration of this embodiment is as shown in the figure,
The principle box 21 includes an incident side ionization chamber 22 and an emission side ionization chamber 23, and a variable slit plate 24 having an adjustable slit between them. Then, the incident X-ray 25 is made incident on the incident side ionization chamber 22, passes through the slit of the variable slit plate 24, is guided to the emission side ionization chamber 23, and is emitted as the emitted X-ray 26 toward the measured sample surface. Is becoming

As for the control system, the X-ray intensity signal of the incident X-ray 25 detected by the incident side ionization chamber 22 is amplified by the amplifier 27, converted into a frequency signal by the V / F converter 28, and controlled. To the vessel 34. On the other hand, the emission X-ray 26 detected by the emission side ionization chamber 23
Is amplified by the amplifier 29, converted into a frequency signal by the V / F converter 30, and guided to the controller 34.

A signal representing the photon energy of the X-ray detected by the photon energy detector 33 installed at an appropriate place is also introduced to the controller 34.

The controller 34 compares the intensity signal of the incident X-ray 25 detected by the incident side ionization chamber 22 and the intensity signal of the emitted X-ray 26 detected by the emission side ionization chamber 23 with a control signal. The optical axis of the X-ray spectroscope 32 is controlled so that the emitted X-rays 26 are maximized. In this case, depending on the measurement mode, the output X
Rather than maximizing line 26, it can be constant.

Further, the direction of the dispersive crystal plate of the X-ray spectroscope 32 is controlled by a signal representing the photon energy of the X-rays detected by the photon energy detector 33, and the X-ray spectroscope 32 is controlled.
The wavelength of the line can be constant. In this case,
Instead of keeping the X-ray wavelength constant, it is possible to operate so as to sweep the wavelength. Further, when the optical axis of the X-ray spectroscope 32 is controlled by the control signal obtained by comparing the intensity signal of the incident X-ray 25 and the intensity signal of the outgoing X-ray 26 as described above, the position of the slit of the variable slit plate 24 is controlled. The shape and shape can also be controlled.

The above-mentioned control of the X-ray intensity and control of the wavelength can be performed simultaneously without separately performing them.

(Third Embodiment) FIG. 3 is an explanatory diagram of an X-ray spectrometer controller according to a third embodiment of the present invention. In this figure, 41 is an ionization chamber, 42 is a variable slit plate, 43 is a two-dimensional X-ray detector, 44 is an incident X-ray, 45 is an outgoing X-ray, and 46.
Is a variable slit controller, 47 and 49 are V / F converters, 4
8 is an amplifier, 50 is an X-ray spectroscope, 51 is a photon energy detector, and 52 is a controller.

The X-ray irradiation apparatus of this embodiment is the X-ray irradiation apparatus of the first embodiment.
The main difference from the radiation irradiator is that a two-dimensional X-ray detector 43 is used instead of the ionization chamber as a means for detecting incident X-rays.

The structure is as shown in the figure, but a variable slit plate 42 is arranged on the X-ray incident side of the ionization chamber 41, and a two-dimensional X-ray detector or a plurality of photo detectors are arranged on the incident side of the variable slit plate 42. An X-ray detector 43 in which diode elements are arranged two-dimensionally is formed, and an incident X-ray 44 having a cross section larger than the slit of the slit plate 42 is incident,
A part thereof passes through the slit of the slit plate 42, passes through the ionization chamber 41, and is emitted as an emitted X-ray 45 toward the sample to be measured.

Then, the signal representing the X-ray intensity detected by the two-dimensional X-ray detector 43 formed on the incident side of the variable slit plate 42 is converted into a frequency signal by the V / F converter 47 and is then sent to the controller 52. Be guided. Further, the signal representing the passing X-ray intensity detected by the ionization chamber 41 is the amplifier 48.
Is amplified, converted into a frequency signal by the V / F converter 49, and guided to the controller 52. It is also possible to use an A / D converter instead of the V / F converter 49 and process it with a digital signal.

A signal detected by the photon energy detector 51 installed at an appropriate location for receiving X-ray irradiation is also guided to the controller 52. The photon energy detector 51 may be the two-dimensional X-ray detector 43 formed on the incident side of the variable slit plate 42. Then, in the controller 52, the signal of the two-dimensional X-ray detector 43 and the signal of the ionization chamber 41 are processed, and the variable slit plate 42 is processed.
The optical axis of the X-ray spectroscope 50 is controlled so that the X-rays that have passed through the slits become the emission X-rays 45 and the intensity of emission is maximized.

Further, by processing the signal from the photon energy detector 51 and controlling the orientation of the dispersive crystal plate of the X-ray spectroscope 50, it is possible to prevent the photon energy of the emitted X-rays 45, that is, the wavelength from varying. Alternatively, the wavelength of the emitted X-ray 45 can be swept while monitoring the wavelength by the photon energy detector 51. In the present embodiment, since the two-dimensional X-ray detector 43 is formed on the X-ray incident side of the ionization chamber 41, it is possible to detect the exact position of the incident X-ray and control the optical axis of the X-ray more accurately. You can

In this embodiment, since the two-dimensional X-ray detector 43 is formed on the X-ray incident side of the variable slit plate 42, the X-rays are incident through the atmosphere and the molecules in the atmosphere are incident. Even if an intensity distribution is generated which is scattered by the X-rays and the intensity of the surrounding X-rays is reduced, the intensity distribution is detected by the two-dimensional X-ray detection element 43 and the optical axis of the X-ray spectroscope is controlled to obtain the maximum intensity. It is possible to control so that the distributed X-rays always pass through the slits of the variable slit plate 42.

An X-ray of a desired intensity is slit by the variable slit controller 46 by the signal of the two-dimensional X-ray detector 43 formed on the X-ray incident side of the variable slit plate 42. It is also possible to control the shape and area of the slit of the variable slit plate 42 so as to pass through. In each of the above embodiments, the variable slit plate 42 is used, but it goes without saying that even a fixed slit plate has an effect commensurate with its configuration.

[0031]

According to the present invention, since the wavelength and the optical axis of the excited X-ray can be controlled separately or both of them, and the automatic control can be successively performed, the X-ray is always kept at the maximum or constant intensity.
Alternatively, it is possible to irradiate a specific narrow region on the sample to be measured with a constant wavelength or by sweeping the wavelength, and the fluorescence X
In the line analysis, the in-plane distribution of the sample to be measured can be easily measured, and the intensity or wavelength shift due to the thermal strain of the dispersive crystal can be prevented, so that the reliability of the measurement result is improved.

Further, even when the wavelength is swept, the optical axis of the excitation X-ray can be kept constant, so that the fluorescence EXAFS (ExteX) which directly reflects the atomic structure around the absorbing atom.
Nded X-ray Absorption Fin
The in-plane distribution of the sample can be accurately measured even in measurement such as e Structure).

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an X-ray spectrometer controller according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an X-ray spectrometer controller according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of an X-ray spectrometer controller according to a third embodiment of the present invention.

[Explanation of symbols]

 1 electron storage ring 2 synchrotron radiation 3 X-ray spectroscope 4 first dispersive crystal plate 5 second dispersive crystal plate 6 X-ray 7 slit plate 8 photon energy detector 9 excited X-ray 10 ionization chamber 11 controller

Claims (6)

[Claims] 1. An X-ray spectroscope that disperses X-rays by a diffraction phenomenon of a crystal plate, a slit plate having a slit installed downstream of the X-ray spectroscope, and an incident X-axis installed upstream of the slit plate. Incident X-ray detector for measuring the intensity of X-rays, outgoing X-ray detector installed downstream of the slit plate for measuring the intensity of outgoing X-rays, the X-ray spectroscope, incident X-ray detector and outgoing X-rays
An X-ray spectrometer control device, comprising: a control system that connects the line detectors to each other. 2. The X-ray spectroscope control apparatus according to claim 1, wherein at least one of the incident X-ray detector and the outgoing X-ray detector is an ionization chamber. 3. The X-ray spectroscope control apparatus according to claim 1, wherein at least one of the incident X-ray detector and the outgoing X-ray detector is a semiconductor X-ray detector. 4. The X-ray spectrometer controller according to claim 1, wherein at least one of the incident X-ray detector and the outgoing X-ray detector is a photoelectron detector. 5. The control system controls the X-ray so as to maximize the intensity of the emitted X-ray emitted from the slit of the slit plate.
The X-ray spectroscope control device according to claim 1, wherein the optical axis of the line spectroscope is controlled. 6. An X-ray spectroscope that disperses X-rays by a diffraction phenomenon of a crystal plate, and an X-ray detector that can detect the wavelength of the X-rays dispersed by the X-ray spectroscope, An X-ray spectroscope control device characterized by controlling the orientation of a crystal plate of a successive X-ray spectroscope by a detection signal of the X-ray detector to control the wavelength and optical axis of the emitted X-ray.