JPS6064239A - X-ray analyzing apparatus - Google Patents

Abstract

PURPOSE:To obtain the secondary electronic image of the surface of a sample without the effect of noises and to prevent the contamination of a sample observing window, by providing a shielding plate on the sample side of the sample observing window so that the plate is freely opened and closed. CONSTITUTION:An observing window 20 is formed at a part of the inside of a case 3, so that the state of a sample 2 in the case 3 can be visually observed. A scintillator PMT23' of the secondary electron detector is provided in the chamber 13 so that the minute structure of an analyzing surface 2a of the sample 2 can be observed, and the secondary electronic image of analyzing surface 2a can be obtained. A movable light shielding plate 25 is provided in order to prevent the input of external light into the chamber 13 from the window 20 and to prevent the decrease in transparency of lead glass 21 of the window 20 during the operation of the PMT23'.

Description

[Detailed description of the invention] The present invention relates to an X-ray analysis device.

2. Description of the Related Art Conventionally, X-ray analyzers have been widely used, which emit X-rays from a sample by irradiating the sample with an electron beam, and analyze elements contained in the sample based on the X-rays. In this X-ray analyzer, an observation window made of lead glass is installed in the main body case of the device so that the operator can monitor the condition of the sample with the naked eye. It is common practice to provide a photomultiplier tube (PMT) inside the main body case to obtain a secondary electron image.

However, X-ray analyzers that meet these requirements have the following problems.

In other words, sample vapor generated when the sample is irradiated with an electron beam and residual gas ionized by the electron beam, etc.7
The problem is that it adheres to the 5S glass window as a contaminant and obstructs visibility, and in the case of a device equipped with a PMT, the PMT is destroyed by external light from the observation window or noise is generated due to light blocking.

Therefore, an object of the present invention is to provide an X-ray analyzer equipped with a glass window for observation and a PMT for observing the sample surface, which can solve the above-mentioned conventional problems all at once.

The configuration of the X-ray analyzer according to the present invention is characterized in that a light shielding plate is attached to the sample side of the sample observation window provided in the wall of the sample chamber so as to be openable and closable. In this way, if a light shielding plate is provided and the sample observation window is closed with the light shielding plate closed,
No external light enters the PMT, and a secondary electron image of the sample surface can be obtained without the influence of noise due to stray light, and the sample observation window can be effectively prevented from becoming dirty. The condition of the sample can be visually observed through the sample observation window.

In addition, a switch is provided that operates in conjunction with the opening and closing of the light shielding plate.
When the sample is removed from the observation window, the PMT
The high-voltage power source may be turned off. With this configuration, when the light shielding plate comes off from the observation window, the high voltage power of the PMT is always turned off, so the light entering from the observation window
It is possible to reliably prevent the MT from being destroyed.

Hereinafter, the present 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 is a device that extracts X-rays emitted from a sample by scanning the sample with an electron beam and analyzes the components of the sample based on the X-rays. A case 3 for storing the sample 2 is provided. The sample 2 is placed on a sample holder 4 provided at the bottom of the case 3, and the case 5 has an opening 5a at the other end of the vacuum tube 5, which is closed at one end. They are connected airtight so that you can see through them. 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 sealed with a vacuum (not shown) so as not to interfere with the travel of the electron beam. It is evacuated by a pump, and the electron gun 6 and sample 2 are placed in the vacuum region.

An electron lens 8 for converging the electron beam 7 emitted from the electron gun 6 and a lens for scanning the surface 2a of the sample 2 with the electron beam 7 converged by the electron lens 8 are disposed around the outer periphery of the vacuum t-use 5. A scanning coil 9 is provided, and by passing a sawtooth wave current through the scanning coil 9, the sample 2 can be repeatedly scanned in a predetermined direction by the narrowly focused electron beam 7. Note that the reference numeral 10 indicates a cover 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 12 having a window 11 provided inside the case B
Accordingly, the inside of the case 6 is divided into a chamber 15 and a chamber 14, with the chamber 13 serving as a sample chamber. On the other hand, a spectroscopic crystal plate 15 and an X-ray detector 16 are housed in the chamber 14, and an electron beam 7 is applied to the sample 2 placed in the chamber 13.
X-rays 17 emitted from sample 2 when irradiated with
The light enters the spectroscopic crystal plate 15 through the window 11 and reaches the X-ray detector.

An observation window 20 is formed in a part of the case 5 so that the operator can visually observe the state of the sample 2 inside the case 3. A glass 21 is fitted. Near the window 20, there is a room 15.
A lamp 22 for illuminating the inside is provided as shown in the figure, so that when the operator looks into the inside of the case 6 through the window 20, the sample 2 can be clearly seen.

In order to be able to observe the fine structure of the analysis surface 2a of the sample 2, a mini-chillator 25' of a secondary electron detector is provided in the chamber 15, and the analysis surface 1a of the sample 2 is also emitted. A secondary electron image of the analysis surface 2a of the sample 2 can be obtained using the secondary electrons 24. The video output signal C' from the PMT23N is sent to a monitor television (not shown).

During use of the PMT 23j, external light is prevented from entering the chamber 16 through the window 2o, and residual gas ions and/or sample vapor adhere to the sample-side surface of the lead glass 21, reducing the transparency of the lead glass 21. In order to prevent a decline in
A movable light shielding plate 25 is provided.

In FIG. 2, the vicinity of the window 20 is enlarged and shown in detail. Explaining based on FIG. 2, the lead glass 21 has a window 20 cut out in a shape corresponding to the shape of the lead glass 21.
is provided with an inward flange 26, and the lead glass 2
1 is stopped by this inward flange 26, and is airtightly fixed via an O-ring 27 installed between the lead glass 21 and the inward flange 26.

Next to the window 20, attach the case 2 to the lamp assembly 28 including the knob 22 in the same manner as with the lead glass 21.
3, and the lamp 22 is configured to be supplied with electric power from a power source (not shown).

A light-shielding plate 25 is arranged in front of the window 20 and the lamp 22 on the sample side, and a support shaft 29, one end of which is fixed to the end of the light-shielding plate 25, is rotatably attached to the wall of the case 6. The other end of the support shaft 29 is fixed to an operating lever 30. Therefore, by operating the lever 30, the light shielding plate 25 can be rotated and the window 20 can be opened and closed.

Therefore, as shown in FIG. 3, when the lever 30 is in the closed position, the window 20 is closed by the light shielding plate 25, allowing outside light to enter the room.
At the same time, the lamp 22 is hidden from the sample 2 and the interior of the chamber 13 is illuminated by the lamp 22.
is prevented.

On the other hand, when the lever 30 is in the open position, the light shielding plate 25
0 and the lamp 22, the sample 2 is illuminated by the lamp 22, and the operator can visually observe the condition of the sample 2 through the window 20.

In order to reliably prevent the PMT from being damaged by light from the lamp 22 and incident light from the window 20 when the lever 30 is in the open position, the opening/closing control is performed using an operator 61 fixed to the lever 30. A microswitch 32 is fixed to the case 3, and the microswitch 62 controls the supply of high-voltage power to the PMT 23 and the power to the lamp 22.

As shown in FIG. 4, the microswitch 32 has two interlocking contacts 32a and 32b, and when one of these two contacts 32a, 321) is closed, the other is closed. It is configured to open and not close at the same time. High voltage is supplied to the PMT 23 from a high voltage power supply 33 via a contact 32, while power is supplied to the lamp 22 from a power supply 34 via a contact 32b. The micro switch 32 is the lever 30
is in the closed position shown by the solid line in FIG. 6, the contact 32a is closed, the contact 321) is open, and P
A high electric current FE is supplied to MT, and the lamp 22 is turned off. When the lever 30 is turned counterclockwise from the position indicated by the solid line in FIG. 3, and the operator rotor 1 is removed from the microswitch 32, the contact 32a is opened and the contact 321) is closed.

According to such a configuration, when the lever 60 is in the closed position, the chamber 13 is almost in a non-illuminated state, and P M T 2
3, it is possible to obtain an excellent secondary electron image with less noise caused by stray light, and the PMT 23 is not damaged by external light. Furthermore, the lead glass 21 and the lamp 22 are covered by the light shielding plate 25, so that the chamber 1! It is possible to effectively prevent ions of the residual gas in I, vapor of the sample 2, etc. from adhering to the lead glass 21 and the lamp 22.

On the other hand, in order to open the lever 50, when the lever 30 is slightly moved counterclockwise from the state shown by the solid line in FIG. 5, the high voltage is first supplied to the PMT 23 before the window 20 opens. The operation is stopped and the lamp 22 is turned on. Therefore, when the lever 30 is in the open position and the window 20 is fully opened, the operator can visually observe the sample 2 through the window 20, and the PMT 23 is protected from being destroyed by external light or the light from the lamp 22. can be reliably prevented.

According to the present invention, as described above, a light-shielding plate is provided, and normally the sample observation window is kept closed, so that no external light enters the PMT, and the secondary light on the sample surface In addition to being able to obtain an electronic image without the influence of noise caused by stray light, it is also possible to effectively prevent the sample observation window from becoming contaminated.And, if desired, by opening the light shielding plate, it is possible to remove the light from the sample observation window. This has an excellent effect of allowing you to visually check the condition of the sample.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is an enlarged detailed sectional view of the main parts of the device shown in Fig. 1, and Fig. 3 shows the external appearance of the main parts of the device shown in Fig. 1. A partial external view, FIG. 4 is a circuit diagram of a power supply control circuit including a microswitch. 1...X-ray analyzer, 2...sample, 3...case, 13.14...room, 20...window, 21...
・Lead glass, 22... Lamp, 26... Secondary electron multiplier type 24... Secondary electron, phototube, 25... Light shielding plate, 60... Operation lever, 61...
・Operator, 63... High voltage power supply, 32... Micro switch, Applicant Daini Seikosha Co., Ltd. Agent Patent Attorney Mogami Affairs Figure 3 Figure 4r7T

Claims (2)

[Claims] (1) In an X-ray analyzer that analyzes the sample based on X-rays obtained from the analysis surface by irradiating the analysis surface of the sample with an electron beam, a sample observation device installed on the wall of the sample chamber An X-ray analysis device characterized by having a light-shielding plate provided on the sample side of the window so that it can be opened and closed. (2) In an X-ray analyzer that analyzes the sample based on the X-rays obtained from the analysis surface by irradiating the analysis surface of the sample with an electron beam, secondary electrons emitted from the sample are In addition to installing a secondary electron detector in the sample chamber,
A light-shielding plate is provided on the sample side of the sample observation window provided on the wall of the sample chamber so as to be openable and closable, and high-voltage power is supplied to the photomultiplier tube of the secondary electron detector according to the opening and closing of the light-shielding plate. on·
An X-ray analyzer characterized in that it is turned off.