JPS6062047A - X-ray analysis device - Google Patents

Abstract

PURPOSE:To strikingly reduce stain of a lead glass in comparison with the prior art by positioning the first mesh electrode held at the earth voltage and the second mesh electrode held at desired positive voltage in the front of the specimen side in a window glass for observing a specimen. CONSTITUTION:The first mesh electrode 23 and the second mesh electrode 24 are provided in the vicinity of surface of a lead glass 21 on the specimen side so as to prevent the sight through a lead glass 21 from being distorbed, with the influence of ionized contaminants attached to the inside of the lead glass 21. The first and the second mesh electrodes 23, 24 are fixed to the surface of inner wall of a case 3, mutually holding electrical insulation by means of a supporting member 25 made of electrical insulating material. The first mesh electrode 23 is connected to the negative electrode of a direct current power supply 26, and is earthed. On the other hand, the second mesh electrode 24 is connected to the positive electrode of the direct current power supply 26 and is held at fixed positive voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray analyzer, and particularly to an
The present invention relates to an X-ray analyzer that can effectively prevent a sample observation window from being contaminated by evaporated vapor from the sample.

The sample is irradiated with an electron beam, resulting in n emitted from the sample.
X-ray analyzers are widely used to analyze X-rays contained in a sample and to analyze the components contained in the sample. In this X-ray analyzer, in the 7th step to increase the resolution of analysis,
It is desirable to make the diameter of the electron beam that irradiates the sample as small as possible, but when the diameter of the electron beam is narrowed down in this way, the irradiated part of the sample becomes high temperature, and part of the sample evaporates.
Alternatively, the residual gas may be ionized by backscattered electrons, and these particles may adhere to the 2" lead glass sample observation window provided in the case, making it impossible for the operator to observe the sample tube adequately. The observation window was soiled from inside the case, and therefore cleaning had to be done from inside the case, so its maintenance was extremely thorough.

Therefore, an object of the present invention is to prevent contaminants from adhering to the sample observation glass window of an X-ray analyzer.
The inventor of the present invention, whose purpose is to provide a CX-ray analyzer, has observed and observed in detail the state of contamination of lead glass, and has confirmed that the contamination becomes worse as one approaches the center of the lead glass. I met. As a result of various experiments, we found that the cause of this staining was that the inner surface of the transparent glass plate that made up the entire observation window was negatively charged. It has been found that the residual gas ions, etc., which have been ionized and have a positive charge, are electrostatically attracted to the glass plate and attached thereto.

The configuration of the X-ray analyzer according to the present invention is such that a first mesh electrode, which is provided in a part of the main body case and which is maintained at the cross-segment position, is provided on the front surface of the sample observation window glass on the sample side, and The second mesh electrode is maintained at a positive potential of . The second mesh electrode is preferably disposed between the first mesh electrode and the window glass, and if the first and second mesh electrodes are provided in this way, the electron beam will ionize the electrodes and the window glass will be ionized. The accumulated contaminants are pushed down by the second mesh electrode to reach the lead glass, and are captured by the first mesh electrode and prevented from adhering to the lead glass. Therefore, only electrically neutral substances such as sample vapor adhere to the lead glass, and staining of the lead glass can be significantly reduced compared to the conventional method.

Hereinafter, the X invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows an embodiment of an X-ray analyzer according to the present invention. The X-ray analyzer 1 scans the sample with an electron beam to emit XIvi! from the sample. '
This is a device that extracts c and analyzes the components of the sample based on the XI, and is equipped with a case 3 for storing the sample 2. The sample 2 is placed on a sample holder 4 provided at the bottom of the case 3, and the case 3 has an opening 5α at the other end of the vacuum tube 5, which is closed at one end. They are connected airtightly so that the inside of the case 3 can be seen. An electron gun 6 is disposed at one end of the vacuum tube 5 so as to face the sample 2, and the inside of the case 3 and the vacuum tube 5 are vacuumed (not shown) so as not to interfere with the electron beam travel. A vacuum is drawn by the pump, and the electron gun 6
and the sample 2 is arranged in a vacuum region.

On the outer periphery of the vacuum tube 5, there is an electron lens 8 for converging the electron beam 7 emitted from the electron gun 6, and for scanning the surface 2α of the sample 2 with the electron beam 7 converged by the electron lens 8. By passing a sawtooth wave current through the scanning coil 9, the sample 2 can be repeatedly scanned in a predetermined direction by the narrowed electron beam 7. What is indicated by property 10 is a force tool for protecting the electron lens 8 and the scanning coil 9, and the space between the cover 10 and the vacuum tube 5 is in a state equal to atmospheric pressure.

A partition wall with a 2t window 11 provided inside the case 3 [
2, the inside of the case 3 is divided into a chamber 13 and a chamber 14, with chamber 13 serving as a sample chamber. On the other hand, room 1
Inside the room 4, a spectroscopic crystal plate 15, an X-ray detector 16, and a crab are stored. Released from sample 2
The configuration is such that L X-rays 17 enter the spectroscopic crystal plate 15 through the window 11 and reach the X-ray detector 16.

An observation window is formed in a part of the case 3 so that the operator can visually check the condition of the sample 2 inside the case 3 at any time! The window 20 is made of transparent lead glass 21.
Is it inset? in, being.

FIG. 2 shows an enlarged and detailed view of the vicinity of this window. As indicated by 11 in FIG. 2, the inner periphery of the window has an inward flange 20 (L
is provided protrudingly, and the lead glass 21 is airtightly fixed to the inwardly directed flange 2ocL via the O-ring 22. In order to prevent ionized RfC contaminants from adhering to the inside of the lead glass 21 and obstructing the view through the lead glass 21k, near the surface of the sample 4111 of the lead glass 21, A first mesh electrode and a second mesh electrode are provided. First and second mesh electrode fields, 2
-1 is fixed to the inner wall surface of the case 3 by a support member 5 made of an electrically insulating material while maintaining electrical insulation from each other, and the first mesh electrode is connected to the negative electrode of the DC power supply 26. Meanwhile, the second mesh electrode diagonal is connected to the positive terminal of the DC power supply 26 and maintained at a predetermined positive potential.

In this way, the first mesh electrode 2 is kept at the end position.
3 and a second mesh electrode 24 maintained at a predetermined positive position 1 are placed on the surface of a lead glass sample 21. As shown in FIG. Even if the residual gas ions 27 run toward the lead glass 21, they are repelled by n% to the first mesh electrode Z1 due to the positive potential applied to the second mesh electrode Z1. I will be arrested. In this way, the material having an electrically positive electrode is more likely to be trapped than the action of the first and second mesh electrodes, and most of the A is on the surface of the lead glass 21.
.

It won't stick to anything. Therefore, there is almost no adhesion to the surface of the lead glass 21. Therefore, simply by adhering electrically neutral substances such as sample vapor to the surface of the lead glass 21, the adhesion of dirt to the lead glass 21 is significantly improved compared to the conventional method. Ru. And each electrode B, 24
Since it is a mesh, visibility through the lead glass 21 is not obstructed.

According to the present invention, as described above, the number of times the window needs to be cleaned is reduced, which not only simplifies maintenance but also allows good observation of the sample at all times.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the X-ray analysis apparatus according to the present invention, and FIG. 2 is an enlarged detailed cross-sectional view showing essential parts of the apparatus shown in FIG. 1 in enlarged detail. 1°. Xi! ! i! Analyzer, 2. . Sample, 3°. Case, 7. . Electron beam, ribs. , window, 21°. lead glass,
23°. First mesh electrode, 24°, second mesh 1a
Pole, 26°. DC power supply. Applicant Daini Seikosha Co., Ltd. Representative Patent Attorney Tsutomu Mogami

Claims (1)

[Claims] 1. An apparatus for detecting X-rays emitted from a sample by irradiating the sample with an electron beam and analyzing the sample, the main body case having a lead glass for observing the sample. In an X-ray analyzer equipped with a glass plate, a glass plate was placed on the nt+ surface of the lead glass on the sample side, and was kept at
X characterized in that it has a first mesh electrode which is maintained at a required positive potential and a second mesh electrode which is maintained at a required positive potential.
Line analyzer.