JP2003008088A - Superconducting magnet unit for x-ray diffraction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting magnet unit for an X-ray diffraction having a small X-ray transmission attenuation rate. SOLUTION: The superconducting magnet unit for the X-ray diffraction comprises superconducting magnets 5a, 5b disposed at upper and lower stages in a vacuum heat insulation container 3, an X-ray incident passage S1, and an X-ray diffraction passage formed between the magnets of the upper and lower stages. The superconducting magnet unit further comprises an inner cylinder 3a formed toward a center of the magnets along a centerline of the container 3 to form an inside wall of the container 3 to dispose a sample for an X-ray diffraction disposed at a center of the upper and lower magnets from out of the container 3, a pair of sector spaces as the X-ray incident passage S1 and the X-ray diffraction passage spreading toward a peripheral wall 3b of the container 3 from the cylinder 3a, and a cover member 15 fixed airtightly to the container 3 and having X-ray passage windows 15b at outside surfaces of the sector spaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnet device for X-ray diffraction, and more particularly to a superconducting magnet device for an X-ray diffraction device which can minimize X-ray attenuation.

[0002]

2. Description of the Related Art Conventionally, since a superconducting magnet device can generate a strong magnetic field, it has been proposed to be applied to various purposes, and is actually used for NMR and other physical property measuring devices.

As an example in which a superconducting magnet device is applied to an X-ray diffractometer in the above-mentioned conventional application fields, Japanese Patent Application Laid-Open No. 7-58 is known.
There is a 365 publication. As shown in FIG. 5, the apparatus described in this publication has a vacuum heat insulation container 3 held on a base 2 and is surrounded by a radiation shield 4 arranged in the vacuum heat insulation container 3 in a vacuum space. A pair of upper and lower superconducting magnets 5a,
5b, a holding frame 11 for holding the same, a current lead 6 formed of a high-temperature superconducting material such as bismuth-based metal, a first-stage cooling stage 7a and a second-stage cooling stage 7b of the regenerative refrigerator 7. It has a structured structure. The radiation shield 4 is thermally contacted with and fixed to the first cooling stage 7a, and the superconducting magnets 5a, 5 inside the radiation shield 4 are fixed.
b is prevented from entering the current lead 6 and the current lead 6.
The current lead 6 is connected to an external power source (not shown) via the lead 12 and the external connection terminal 13.

The superconducting magnets 5a and 5b are composed of an upper magnet 5a and a lower magnet 5b, and superconducting coils are wound around annular winding frames 9a and 9b, respectively, and their outer circumferences are made of copper having good heat conductivity. It is held by the holding frame 11. The holding frame 1
1 is a side frame 11a arranged on the outer peripheral surfaces of the upper and lower superconducting magnets 5a and 5b, and a superconducting coil winding frame 9a and the side frame 1 arranged on the upper surface of the upper magnet 5a.
An upper frame 11b bolted to 1a and a lower superconducting coil winding frame 9 arranged on the lower surface of the lower magnet 5b.
b and a lower frame 11c bolted to the side frame 11a. Also, the upper and lower superconducting magnets 5a, 5
A copper support member 8 for supporting an electromagnetic force (attracting force) acting between both magnets is interposed between b.

Further, in the vacuum heat insulating container 3, an inner cylindrical portion 3a which forms an inner wall of the vacuum heat insulating container 3 along the central axis of the vertical direction and communicates with the atmosphere is provided with the superconducting magnets 5a, 5a.
The inner cylinder portion 4a of the radiation shield is arranged so as to pass through the center of 5b so as to surround the outer surface of the inner cylinder portion 3a, and a sample for X-ray diffraction is The center of the inner cylinder 3a between the superconducting magnets 5a and 5b can be inserted and removed from the outside.

The support member 8 disposed between the upper and lower superconducting magnets 5a and 5b has the upper and lower superconducting magnets 5a and 5a, as shown in FIG. 6 which is a sectional view taken along line AA of FIG.
5b is not arranged in the entire area, and a first fan-shaped space S1 fanned out from the center at an angle α and a second fan-shaped space S2 fanned out at an angle β are formed. Is a space opened to the outside of the vacuum heat insulating container 3 by side walls 3b and 3c forming part of the outer wall of the vacuum heat insulating container 3, and the first fan-shaped space S1 and the second fan-shaped space S2 are , X-ray entrance passages and X-ray diffraction passages are formed, respectively.

[0007]

In the superconducting magnet device for an X-ray diffractometer having such a structure, the sample 10 is inserted from the outside into the center position of the upper and lower superconducting magnets 5a and 5b in the inner cylindrical portion 3a. , An X-ray beam emitted from an X-ray generator (not shown) is applied to the sample 10 through an X-ray entrance passage S1 which is an atmospheric space, and the diffracted X-rays diffracted by the sample 10 are in the atmosphere. The X-ray image is received by an X-ray image receiving device (not shown) through the X-ray diffraction path S2, and it is inevitable that the X-rays are attenuated while passing through the atmosphere. Therefore,
It was not always a sufficient apparatus for X-ray diffraction in which a slight difference was a problem.

The position of the sample 10 in the inner cylinder 3a is confirmed by visual observation from above the inner cylinder 3a, but only by visual observation from the vertical direction in a narrow cylinder. In position determination, an appropriate determination is not always always made, and there is a problem that the operator must rely on the intuition of the operator.

The present invention is to solve the above problems,
The first purpose is to minimize the attenuation of X-rays, and the second purpose is to enable accurate determination of the sample position in the inner cylindrical portion.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, in which a superconducting magnet is arranged in upper and lower two stages in a vacuum heat insulating container, and the upper and lower superconducting magnets are arranged in two stages. In a superconducting magnet device for an X-ray diffraction device, wherein an X-ray incident passage and an X-ray diffraction passage are formed between the magnets, the superconducting magnet is formed along a center line of the vacuum heat insulating container toward a central portion of the superconducting magnet. And an inner cylinder for forming an inner wall of the vacuum heat insulating container, and an X-ray diffraction sample from the outside of the vacuum heat insulating container to be placed in the central portion of the upper and lower superconducting magnets, and the vacuum from the inner cylinder. A pair of fan-shaped spaces serving as the X-ray incident passage and the X-ray diffraction passage that spread toward the peripheral wall of the heat insulating container, and an outer surface of the fan-shaped space are airtightly fixed to the vacuum heat insulating container and an X-ray passage window. A cover member having
In addition, the inside of the X-ray entrance passage and the X-ray diffraction passage is not a vacuum space or a space that is airtightly separated from the inside of the vacuum heat insulating container and is filled with a gas having a smaller X-ray transmission attenuation factor than the atmosphere. The X-ray passage window of the cover member is formed of a metal material or a polymer material having a smaller X-ray transmission attenuation factor than the atmosphere.

By adopting such a configuration, X-rays are incident and diffracted through a passage formed so that the attenuation rate is smaller than that in the atmosphere. It has a high resolution and precision. still,
Beryllium or a polyimide resin is preferable as the material having a smaller X-ray transmission attenuation factor than the atmosphere used in the present invention.

Further, in addition to the above structure, it is formed between the upper and lower superconducting magnets independently of the X-ray incident passage and the X-ray diffraction passage, and is vacuum insulated from the inner cylindrical portion. If a pair of cylindrical X-ray transmission passages for observing the sample position are linearly arranged toward the peripheral wall of the container,
It is possible to observe the installation state of the sample by X-rays through the X-ray transmission passage, which makes it extremely easy to properly place the sample.

Incidentally, the inside of the X-ray transmission passage for observing the sample installation state is also evacuated or filled with a gas having a smaller X-ray transmission attenuation factor than the atmosphere, like the X-ray incident passage and the diffraction passage. Although it is possible to do so, since it is not required to be as precise as that, it is possible to use an X-ray passage open to the atmosphere.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the drawings of the embodiments. FIG. 1 is a cross-sectional view of essential parts showing a superconducting magnet device for an X-ray diffraction device according to the present invention, and the same components as those of the device of FIG. 5 are designated by the same reference numerals. In the figure,
The vacuum heat insulating container 3 is held on the base 2, and the vacuum heat insulating container 3 is held.
Inside the vacuum space surrounded by the radiation shield 4, the upper and lower superconducting magnets 5a and 5b, a holding frame 11 for holding them, and a first stage cooling stage 7a of the regenerator 7
And the second cooling stage 7b are arranged, and the radiation shield 4 is heated by the material 14 having a high thermal conductivity such as a copper plate or a copper wire on the first cooling stage 7a. The radiant heat from the outside is prevented from entering the superconducting magnet 5 and the like inside thereof. The superconducting magnet 5 is composed of a pair of upper and lower superconducting magnets 5a and 5b, each of which has an annular winding frame 9a.
The superconducting coil is wound around a and 9b, and the outer periphery thereof is held by a holding frame 11 made of copper having good heat conductivity.
Since the structure of the holding frame 11 is substantially the same as that of the case of FIG. 5, detailed description thereof will be omitted. In addition, a point that a copper support member 8 for supporting an electromagnetic force (attracting force) acting between both magnets is interposed between the upper and lower superconducting magnets is basically the same as that of FIG. It is the same. In the apparatus of the present invention, the lid member 22 is detachably attached to the cylindrical portion 3a by the bolts 23 on the upper portion of the cylindrical portion 3a, and further, the vacuum pump for degassing the inside of the cylindrical portion 3a. Is attached to the nozzle 24.

Next, FIG. 2 is a Q-Q sectional view of FIG. 1 which is a cross section between the upper and lower superconducting magnets, and FIG.
FIG. As shown in both figures, the structure of this cross-section is completely different from the conventional one shown in FIGS. That is, in the device according to the present invention, the structure of the vacuum heat insulating container 3 between the upper and lower superconducting magnets has a cylindrical outer peripheral wall 3b and a central inner cylindrical portion 3a.
And a pair of radial side walls 3c forming a first fan-shaped space S1 having a predetermined inner angle α and a pair of upper and lower bottom walls 3e of the first fan-shaped space S1, and similarly a second fan-shaped space S2 having a predetermined inner angle β.
A pair of side walls 3d in the radial direction and a pair of upper and lower bottom walls 3f of the second fan-shaped space, both sides of the inner cylindrical portion 3a, and independently of the first and second fan-shaped spaces S1 and S2. Cylindrical walls 3g and 3g 'for forming a pair of linearly arranged cylindrical spaces (first cylindrical space T1 and second cylindrical space T2)
It consists of In addition, the first and second fan-shaped spaces S1,
The upper and lower bottom walls 3e and 3f of S2 are both formed in a trumpet shape so that the width in the vertical direction expands from the inside to the outside.

Furthermore, the first and second fan-shaped spaces S1 and S2.
A cover member 15 is attached to the outer peripheral surface of each of the bolts 1 by means of bolts 1 mounted on brackets 16 arranged at appropriate positions on the outer surface of the vacuum heat insulating container 3.
The two fan-shaped spaces S1 and S2, which are internal spaces, are fixed to each other by an airtight structure so as to have an airtight structure against the outside air. Further, the cover member 15 is a support plate formed of a stainless steel material or the like having an opening 15b serving as an X-ray transmission window in the central portion, as shown in FIG. 15a has a structure in which the periphery of 15a is fixed to the bracket 16 by a bolt 17, and the entire surface including the opening 15b in the central portion is a thin plate 18 formed of a material having an X-ray transmission attenuation factor smaller than that of the atmosphere. It is covered, whereby the opening 15b is hermetically sealed.

The material used in the present invention having a lower X-ray transmission attenuation factor than the atmosphere is typically beryllium or a polyimide resin. The usage of this material is
It goes without saying that, as shown in the figure, in addition to bonding so as to cover the entire surface of the support plate 15a including the opening 15b, a plate member formed of these materials may be airtightly mounted in the opening 15b.

Further, an opening is formed in a boundary portion 21 of the cylindrical portion 3a with the first and second fan-shaped spaces S1 and S2. Similarly, an opening is also formed in the boundary portion 20 between the cylindrical space 3a and the cylindrical spaces T1 and T2 that serve as X-ray passages for observing the installation position of the sample.
A window member 19 is airtightly attached to the outside air on the outer side surface of T2. As a result, the inside of the cylindrical portion 3a and the first,
The second fan-shaped spaces S1 and S2 and the cylindrical spaces T1 and T2 have a structure in which they communicate with each other.

Next, the operation of carrying out the X-ray diffraction analysis of the sample by the apparatus of the present invention will be explained.
Remove the lid member 22 on the top of the sample 10 from the top opening.
And installed on the same plane as the two fan-shaped spaces S1 and S2.

Next, the lid member 22 is attached to the upper opening of the cylindrical portion 3a and hermetically sealed, and subsequently, the deaeration nozzle 24 arranged in the lid member 22 is connected to a vacuum pump (not shown). The inside of the cylindrical portion 3a is deaerated. Then, the cylindrical spaces T1 and T2 and the fan-shaped spaces S1 and S2 communicating with the cylindrical portion 3 are also deaerated to a vacuum.

In this state, first, the first cylindrical space T1
The sample 10 is irradiated with X-rays or neutrons from an X-ray irradiator or neutron irradiator (not shown) disposed outside the second tubular space T2, and X-rays or By arranging a neutron image receiving device and observing an X-ray image of the sample, it is observed whether or not the sample is arranged at an appropriate position. If it is not in the proper position, the upper lid member 22 of the inner cylindrical portion 3a is removed and the sample position and orientation are adjusted again and the sample is placed in the proper position.

When the proper arrangement of the sample 10 is confirmed in this manner, the opening 15b serving as an X-ray transmission window of the cover member 15 in the first fan-shaped space S1 serving as an X-ray irradiation passage.
An X-ray irradiator (not shown) is arranged on the outside of the cover, and an X-ray image receiver (not shown) is arranged on the outside of the opening 15b of the cover member 15 in the second fan-shaped space S2 serving as an X-ray diffraction passage. Then, a predetermined X-ray diffraction operation is performed.

As described above, since the X-ray irradiation passage S1 and the diffraction passage S2 are maintained in a vacuum state in which the X-ray transmission attenuation rate is lower than that of the atmosphere, the X-axis between the two fan-shaped spaces S1 and S2 is maintained. The attenuation of the X-rays is minimized, and the X-ray transmission window 15b of the cover member 15 through which the X-rays are irradiated when the irradiation passage S1 is irradiated and when an image is received also has an X-ray transmission attenuation rate from the atmosphere. Since it is formed of a material having a low X, the attenuation of X-rays at this portion can also be suppressed. Therefore, it becomes possible to minimize the total attenuation rate of X-rays as compared with the conventional case where the X-ray passage is open to the atmosphere, and it is possible to obtain a clearer image as a diffraction image. Become.

Here, in the present embodiment, the insides of the first and second fan-shaped spaces S1 and S2 are also maintained in a vacuum state in which the X-ray transmission attenuation rate is lower than that of the atmosphere, and outside the fan-shaped spaces S1 and S2. The cover member 15 is also characterized in that beryllium or a polyimide resin having a smaller X-ray transmission attenuation factor than the atmosphere is arranged also in the X-ray passage window portion, but the present invention is not limited to this. However, there are various modifications as described below.

First, instead of forming a vacuum inside the fan-shaped spaces S1 and S2 and the cylindrical portion 3a, a gas having a smaller X-ray transmission attenuation factor than the atmosphere, such as helium gas, is enclosed in the space. There is also. In this case, the helium gas is supplied after the inside of the space is evacuated from the nozzle 24 formed in the lid member 22. In the case of this method, the action time of the vacuum stress acting on the opening 15b of the cover member 15 when the fan-shaped space is in a vacuum state can be shortened, and beryllium or polyimide attached to the opening 15b can be shortened. It has the effect of suppressing damage to the resin.

Further, in any of the above methods, the fan-shaped spaces S1 and S2 and the cylindrical space T when the sample 10 is taken in and out.
1 and T2 must be evacuated and helium must be supplied, but the cylindrical part 3a is necessary for taking in and out the sample.
Therefore, the cylindrical portion 3a and both fan-shaped spaces S1 and S2 are
Beryllium or a polyimide resin, which has a lower X-ray transmission attenuation factor than the atmosphere described above, is airtightly arranged in the boundary portion 21 with the space T1 and the boundary portion 20 with the cylindrical spaces T1 and T2.
1, S2 and the cylindrical spaces T1, T2 and the cylindrical portion 3a have an airtight structure, and the fan-shaped spaces S1, S2 and the cylindrical space T1,
It is also possible to always keep the inside of T2 in a vacuum state or a helium gas filled state. If you do like this,
When the sample is taken in and out, only the cylindrical portion 3a may be opened to the atmosphere, deaerated, or filled with helium gas, so that the operation time is shortened.

Since the two cylindrical spaces T1 and T2, which are X-ray passages for observing the installation position of the sample, are X-ray passages for confirming the position of the sample, the attenuation rate is not so much. Since there is no need to consider it, there is no problem even if it is open to the atmosphere. Therefore, the X-ray transmission window made of beryllium or polyimide resin is hermetically attached to the boundary portion 20 of the cylindrical portion 3a with the cylindrical spaces T1 and T2,
It is also possible to make the outer end part of the structure open to the atmosphere.

Further, although it is inevitable that the inside of the inner cylindrical portion 3a is communicated with the atmosphere for loading and unloading the sample,
Since the air layer in the inner cylindrical portion 3a is extremely shorter than the fan-shaped spaces S1 and S2, the X-ray transmission attenuation amount can be ignored even when the atmosphere is open. Therefore, the boundary portion 21 with the first and second fan-shaped spaces S1 and S2, which is an X-ray passing portion, is formed airtightly with beryllium or polyimide resin as described above, and both fan-shaped spaces S1 and S2 are It is also possible to always maintain the vacuum state or the helium gas filled state. In particular, in the case of a system in which both fan-shaped spaces S1 and S2 or the cylindrical spaces T1 and T2 are constantly maintained in vacuum,
It is also possible to communicate these spaces with the inside of the vacuum heat insulating container 3.

[0029]

As described above in detail, according to the present invention, X
Both the fan-shaped spaces S1 and S2, which are X-ray irradiation passages or X-ray diffraction passages that are passages for X-rays, are filled with a gas having a smaller X-ray transmission attenuation factor than vacuum or the atmosphere. Since a beryllium or a polyimide resin having a smaller X-ray transmission attenuation factor than the atmosphere is also arranged in the opening 15b serving as an X-ray passage of the cover member that defines the fan-shaped space and the outside, the X-ray is irradiated. Most of the X-ray passage while being diffracted and received has a smaller X-ray transmission attenuation factor than the atmosphere, and the X-ray attenuation is greatly suppressed compared to the conventional method using the atmosphere as the X-ray passage. As a result, it will be possible to obtain more precise diffraction data, and it is expected that this will greatly contribute to the progress of science and technology in Japan.

Further, if the linear X-ray transmission passages T1 and T2 for observing the sample position are formed independently of both the fan-shaped spaces S1 and S2 that are the X-ray irradiation passage and the X-ray diffraction passage, It is possible to confirm the position of the sample by irradiating X-rays or neutron rays from the passages T1 and T2.
It becomes easy to take a line diffraction image.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of essential parts showing an example of a superconducting magnet device for X-ray diffraction according to the present invention.

FIG. 2 is a sectional view taken along line QQ of FIG.

FIG. 3 is a view on arrow S-S in FIG.

FIG. 4 is a view on arrow RR in FIG.

FIG. 5 is a conceptual diagram of an essential part showing an example of a conventional superconducting magnet device for X-ray diffraction.

6 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols] 3 vacuum insulation container 3a Inner tube part 4 Radiation shield 5 Superconducting magnet 7 Cold storage cooler 8 Support members 9 reels 10 samples 11 holding frame 15 Cover member 15b Cover member opening (X-ray transmission window) 19 Window member for cylindrical space 20 Boundary between the inner cylindrical part and the cylindrical space 21 Boundary of inner cylinder with fan-shaped space S1 First fan-shaped space (X-ray irradiation passage) S2 Second fan-shaped space (X-ray diffraction passage) T1 First cylindrical space (X-ray transmission passage for sample position observation) T2 Second cylindrical space (X-ray transmission passage for sample position observation)

Claims (11)

[Claims] 1. Superconducting magnets (5a, 5b) are arranged in upper and lower two stages in a vacuum heat insulating container (3), and an X-ray entrance passage (S1) and an X-ray are provided between the upper and lower superconducting magnets. Diffraction path (S
2) in the superconducting magnet device for X-ray diffractometer, wherein the vacuum insulating container (3) is formed along the center line of the vacuum insulating container (3) toward the center of the superconducting magnet. An inner cylinder part (3a) for forming an inner wall and for disposing an X-ray diffraction sample (10) from the outside of the vacuum heat insulating container (3) in the central part of the upper and lower superconducting magnets, and the inner cylinder part. A pair of fan-shaped spaces as the X-ray incident passage (S1) and the X-ray diffraction passage (S2) extending from (3a) toward the peripheral wall (3b) of the vacuum heat insulating container (3), and the outside of the fan-shaped space. The vacuum insulation container (3) is provided on each of the side surfaces.
A cover member (15) that is airtightly fixed to the X-ray passage window (15b) and has the X-ray entrance passage (S1) and the X-ray diffraction passage (S).
The inside of 2) is a vacuum space or a space that is airtightly partitioned from the inside of the vacuum heat insulating container (3) and is filled with a gas having a smaller X-ray transmission attenuation factor than the atmosphere, and X of the cover member (15). The superconducting magnet device for an X-ray diffraction device, wherein the ray passage window (15b) is formed of a metal material or a polymer material having a smaller X-ray transmission attenuation factor than the atmosphere. 2. The superconducting magnet device for an X-ray diffraction apparatus according to claim 1, wherein the X-ray passage window (15b) is made of beryllium or polyimide resin. 3. The X-ray entrance passage (S1) and the X-ray diffraction passage (S2) are vacuum spaces that are hermetically defined from the inside of the vacuum heat insulating container (3). Item 1
Alternatively, the superconducting magnet device for an X-ray diffractometer according to item 2. 4. The X-ray diffraction apparatus according to claim 1, wherein the X-ray entrance passage (S1) and the X-ray diffraction passage (S2) are filled with helium gas. Superconducting magnet device. 5. An X-ray transmission window is provided in a portion of the inner tubular portion (3a) facing the X-ray incidence passage (S1) and the X-ray diffraction passage (S2), and the atmosphere is provided in the X-ray transmission window. The superconducting magnet for an X-ray diffractometer according to any one of claims 1 to 4, wherein a window member (21) made of a metal material or a polymer material having a smaller X-ray transmission attenuation factor is arranged. apparatus. 6. The X-ray entrance passage (S1) and the X-ray diffraction passage (S2) are formed such that the width in the height direction thereof widens from the inside to the outside. Item 7. A superconducting magnet device for an X-ray diffraction device according to any one of items 1 to 5. 7. The superconducting magnets (5a, 5) in the upper and lower two stages.
b) between the X-ray entrance passage (S1) and the X-ray diffraction passage (S2) and between the inner cylindrical portion (3a) and the peripheral wall (3) of the vacuum heat insulating container (3). 7. A pair of cylindrical sample position observing X-ray transmission passages (T1, T2) formed toward 3b) are linearly arranged. Superconducting magnet device for X-ray diffractometer. 8. A window member (19) is provided on the outer surface of the X-ray transmission passage (T1, T2) so as to be airtight to the outside air, and the X-ray transmission passage (T1, T2) is provided. In T2),
A vacuum space or a space in which the inside of the vacuum heat insulating container (3) is airtightly sealed and a gas having a smaller X-ray transmission attenuation factor than the atmosphere is enclosed, and the window member (19) is separated from the atmosphere. The superconducting magnet device for an X-ray diffractometer according to claim 7, which is also formed of a metal material or a polymer material having a small X-ray transmission attenuation factor. 9. The superconducting magnet device for an X-ray diffraction device according to claim 8, wherein the window member (19) is made of beryllium or polyimide resin. 10. The X-ray transmission passages (T1, T2) are
The superconducting magnet device for an X-ray diffraction device according to claim 7, wherein the superconducting magnet device is in communication with the atmosphere. 11. An X-ray transmission window is provided in a portion of the inner cylindrical portion (3a) facing the X-ray transmission passages (T1, T2), and the X-ray transmission attenuation factor is higher than that of the atmosphere in the X-ray transmission window. The superconducting magnet device for an X-ray diffractometer according to any one of claims 7 to 10, characterized in that a window member (20) made of a metal material or a polymer material having a small size is arranged.