JPH0446227Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an energy dispersive X-ray analyzer.

Generally, an X-ray detector used in an energy dispersive X-ray analyzer or the like uses a silicon semiconductor in which lithium is diffused, and therefore the detector is cooled with liquid nitrogen before use. This is because at room temperature, lithium atoms diffuse and performance deteriorates. Figure 1 shows a conventional example of this type of equipment, where 1 is a cooling tank containing liquid nitrogen;
For example, it is made of aluminum. A heat insulating material 2 is placed between the outer and inner walls of the cooling tank 1, and the space where the heat insulating material is placed is evacuated to approximately 10 ^-5 Torr so that the temperature of the inner wall is not transmitted to the outer wall. There is. 3 is liquid nitrogen, and 4 is a plug for putting the liquid nitrogen 3 into the cooling tank 1. A protection pipe 5 is connected to the cooling tank 1 by a flange 6 and has a vacuum inside, and one end of the pipe 5 penetrates the lens barrel 7 while maintaining the vacuum. Reference numeral 8 denotes a heat conduction rod that penetrates inside the protection pipe 5. One end of the heat conduction rod 8 is in close contact with one end of the cooling tank 1, and an X-ray detector 9 made of, for example, a silicon semiconductor is attached to the other end.
are in close contact. 10 is a sample placed in a vacuum chamber, and the sample 10 is irradiated with an electron beam 11. When the surface of the sample 10 is irradiated with this electron beam 11, characteristic X-rays 12 are emitted from that part due to electron transfer in the sample due to the incident electrons. This characteristic X-ray 12 is converted into an electric signal by the X-ray detector 9, and qualitative and quantitative analysis of the sample 10 is performed using an amplifier (not shown in the figure), a multi-channel pulse height analyzer, and the like.

By the way, in a device configured in this way,
The line detector 9 and the heat conductive rod 8 are vacuum-sealed in the protective pipe 5 and have an integral structure. This is to prevent the X-ray detector 9 from being damaged by condensation when it is exposed to the atmosphere in a cooled state.

However, in the conventional apparatus configured in this way, the distance between the objective lens (not shown) for focusing the electron beam 11 onto the sample 10 and the sample 10, the so-called working distance (hereinafter abbreviated as WD) ) changed and the sample 10 moved on the optical axis, the X-ray detector 9 could not be moved or tilted toward the sample. As a result, X-rays could only be detected with a fixed WD, and since the direction of the X-ray detector was fixed, there was no compatibility when changing models.

The present invention was developed in view of the above points, and includes an X-ray detector for detecting X-rays rather than a sample, and
a thermal conductor for connecting the line detector to the cooling bath;
In an apparatus that vacuum-seals the X-ray detector and the thermal conductor and includes a protective pipe for supporting and inserting the X-ray detector and the thermal conductor into the sample chamber, at least a portion of the protective pipe that is inserted into the sample chamber is The X
It is characterized in that means are provided for moving or tilting the line detector.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 is a schematic cross-sectional view showing an embodiment of the present invention. It should be noted that the same components as in FIG. 1 are given the same numbers and their explanations will be omitted. In FIG. 2, 20 is a protection pipe having a telescopic bellows 21 in a part thereof, and 22 is a heat conduction rod having a wire 23 as a heat conduction member in a part thereof. 24 is a metal fitting fixed to the protection pipe 20, and the metal fitting 24 is provided with a rotatable arm 25. 26 is a detector moving rod connected to the arm 25, and the detector moving rod 26 is connected to the lens barrel 7.
It holds a vacuum and is movable through it.

In the apparatus configured as described above, as shown in FIG. 3, when the sample 10 indicated by the broken line is moved by a distance W by a sample moving mechanism (not shown) to the position of the sample 10' indicated by the solid line. By moving the detector moving rod 26 in the direction of the arrow, the protective pipe 20 is bent at the stretchable bellows 21, and the heat conducting rod 22 is also bent by the wire 2.
Since it is bent at the portion 3, the X-ray detector 9 can be moved or tilted in the direction of the sample 10 shown by the solid line. Therefore, even when the WD is varied, the position of the X-ray detector 9 can be easily varied by simply moving the detector moving rod 26.

As described above, in the present invention, in an X-ray detector that is used after being cooled to liquid nitrogen temperature, the X-ray detector can be moved or tilted toward the sample, so that X-rays can be detected with any WD. The present invention provides an energy dispersive X-ray detection device that can be used and is compatible with model changes.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional device, FIG. 2 is a sectional view of an embodiment of the present invention, and FIG. 3 is a diagram for explaining the operating state. 1...Cooling tank, 2...Insulating material, 3...Liquid nitrogen, 4...Plug, 5...Protection pipe, 6...Flange, 7... Lens barrel, 8...Heat conduction rod, 9... X-ray detector, 10...sample, 11...electron beam, 12...
Characteristic X-ray, 20... Protective pipe, 21... Bellows, 22... Heat conduction rod, 23... Wire, 24
...Metal fittings, 25...Arm, 26...Detector moving rod.

Claims (1)

[Scope of utility model registration request] An X-ray detector for detecting X-rays from a sample, a thermal conductor for connecting the X-ray detector to a cooling tank, and vacuum sealing of the X-ray detector and the thermal conductor. and a protective pipe for supporting and inserting into the sample chamber, wherein at least a portion of the protective pipe inserted into the sample chamber is formed of a bellows, and at least a portion of the thermal conductor is formed of a bellows. An energy dispersive X-ray detection device, characterized in that the X-ray detector is made of a flexible member and includes means for moving or tilting the X-ray detector.