JPH09257997A - Spectrometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate replacement of diffraction member and adjustment of optical axis by rotating a diffraction member retaining plate around the rotation axis which does not pass a crossing point between a virtual plane and incident optical axis, the diffraction member being retained at a virtual surface so that the diffraction surface of the diffraction member diffracting an incident electromagnetic wave may cross the incident surface of the incident electromagnetic wave. SOLUTION: The X-ray incident to crystal 11 is diffracted by a certain crystal lattice face of the crystal 11 and the diffraction light comes incident to the crystal 21 retained by a crystal retaining mechanism 20. A retaining mechanism 10 is provided with a crystal retaining plate 14, rotary mechanism 13, support member 15, and the crystal 11 is retained on the crystal retaining surface of the retaining plate 14. The member 15 can turn around the rotary axis 12 perpendicular to the plane including an incident light axis 33 and a going-out axis 34 and can move in parallel along a guide 19 parallel to the optical axis 33. The mechanism 20 is provided with a rotation mechanism 23 and support member 25, and the member 25 has the similar structure to the case of the mechanism 10. With these mechanisms 10, 20 interlocked, the spectral division of the incident X-ray is made possible with a detector 31 fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectroscope, and more particularly to a replacement mechanism for a diffractive member used in the spectroscope.

[0002]

2. Description of the Related Art FIG. 4 shows a crystal exchange mechanism of a conventional double crystal spectrometer. As shown in FIG. 4A, the incident optical axis 55
X-rays incident along the light are diffracted by the crystal 51A, and the diffracted light enters the crystal 61A. The diffracted light incident on the crystal 61A is diffracted again and emitted along the emission optical axis 56. Crystals 51A and 61A are crystal holding members 50 and 6, respectively.
It is held on the 0 crystal holding surface. The crystal holding members 50 and 60 are arranged in a vacuum container.

When the direction of the crystal 51A is changed and the incident angle of the X-ray with respect to the diffraction surface of the crystal 51A is changed, the crystal holding member 60 is arranged along the emission optical axis 56 so that the emission optical axis 56 does not move. The direction of the crystal 61A is changed while moving in parallel. In this way, by interlocking the crystal holding members 50 and 60, the optical axis of the emitted light can be kept constant even if the incident angle of the X-ray is variously changed.

The crystal holding member 50 has a rectangular prism shape, and
Crystals 51A to 51D are respectively held on two side surfaces. Similarly, the crystal holding member 60 also has a quadrangular prism shape, and
Crystals 61A to 61D are respectively held on two side surfaces. The crystal holding members 50 and 60 can rotate around a rotation axis perpendicular to a plane including the incident optical axis 55 and the outgoing optical axis 56 (a plane parallel to the paper surface). By rotating the crystal holding members 50 and 60, the crystal that diffracts X-rays can be exchanged. For example, when the crystal holding member 50 is rotated 90 ° in the direction of the arrow in the figure, the crystal 51B is irradiated with X-rays.

The wavelength interval in which light can be dispersed is limited by the lattice spacing of the crystal. By holding crystals having various lattice intervals in the crystal holding members 50 and 60, crystals having a lattice interval suitable for the wavelength region to be dispersed can be used. Only by rotating the crystal holding member, it is possible to perform spectroscopy in a wide wavelength range.

Further, by holding a plurality of the same crystals in the crystal holding members 50 and 60, the crystal damaged by the X-ray irradiation can be easily replaced with a new crystal while maintaining the vacuum. .

FIG. 4B shows another example of the structure of the crystal holding member. The rotation axes of the crystal holding members 50 and 60 are arranged in the same plane as the incident optical axis 55 and the outgoing optical axis 56. Furthermore, this axis of rotation is parallel to the crystal holding surface. Other configurations are the same as those of the double crystal spectroscope of FIG. Even with the configuration shown in FIG. 4B, the crystal holding member 50
By rotating 60 and 60, the crystal that diffracts X-rays can be easily replaced.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a spectroscope in which the diffractive member can be easily replaced. Another object of the present invention is to provide a spectroscope that can easily adjust the optical axis.

[0009]

According to one aspect of the present invention, a diffractive member for diffracting an incident electromagnetic wave is provided on a virtual plane such that a diffractive surface of the diffractive member and an incident optical axis of the incident electromagnetic wave intersect obliquely. Spectral having a diffraction member holding plate held on the top and a rotation mechanism that rotates the diffraction member holding plate about a rotation axis that is orthogonal to the virtual plane and does not pass through the intersection of the virtual plane and the incident optical axis. Vessels are provided.

By attaching a plurality of diffractive members to the diffractive member holding plate and rotating the diffractive member holding plate by a certain angle about the rotation axis, the diffractive member diffracting the incident electromagnetic wave can be replaced. By attaching a plurality of types of diffractive members in advance, it is possible to use the diffractive member most suitable for the wavelength of the electromagnetic wave to be dispersed. Further, when the rotation angle is reduced, the irradiation position of electromagnetic waves can be moved on the surface of one diffractive member. When a part of the surface of the diffractive member is damaged, the diffractive member can be effectively used by irradiating the other region with electromagnetic waves.

According to another aspect of the present invention, there is provided a spectroscope in which the diffractive member holding plate has a through hole for transmitting the incident electromagnetic wave. The optical axis of the incident electromagnetic wave transmitted through the through hole can be detected to adjust the optical axis. The optical axis of the incident electromagnetic wave can be adjusted without being affected by the arrangement of the diffractive member.

According to another aspect of the present invention, there is provided a spectroscope in which the rotating mechanism rotates the diffraction member holding plate by an ultrasonic motor. By using the ultrasonic motor, it is possible to reduce the size and weight of the spectroscope. When the power supply to the ultrasonic motor is stopped, the ultrasonic motor is automatically braked. Therefore, it is not necessary to constantly supply power to the motor even after adjustment, and power saving can be expected.

According to another aspect of the present invention, there is provided a spectrometer in which the incident electromagnetic wave is an X-ray and the diffractive member is a member having a crystal structure. According to another aspect of the present invention, a diffractive surface of the diffractive member of the other diffractive member for diffracting the incident electromagnetic wave and an optical axis of diffracted light of the incident electromagnetic wave by the diffractive member intersect obliquely. As other diffraction member holding plate to hold on another virtual plane, orthogonal to the other virtual plane, centering on a rotation axis that does not pass through the intersection of the other virtual plane and the optical axis of the diffracted light A spectrometer having another rotating mechanism that rotates the other diffraction member holding plate is provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described by taking a double crystal spectrometer as an example. FIG. 1 shows a schematic view of a double crystal spectrometer according to an embodiment. The two-crystal spectroscope according to the embodiment includes crystal holding mechanisms 10 and 20, and an X-ray detector 31.

The X-ray to be observed propagates along the incident optical axis 33 and enters the crystal 11 held by the crystal holding mechanism 10. The X-rays that have entered the crystal 11 are diffracted by the crystal lattice plane of the crystal 11, and this diffracted light is the crystal holding mechanism 20.
It is incident on the crystal 21 held by. Hereinafter, the crystal lattice plane that causes this diffraction is simply referred to as “crystal lattice plane”. Crystal 21
The diffracted light incident on is again diffracted by the crystal lattice plane of the crystal 21 and propagates along the output optical axis 34 parallel to the input optical axis 33. X-rays propagating along the emission optical axis 34 are X-rays.
It is incident on the line detector 31. The X-ray detector 31 measures the intensity of X-rays.

The crystal holding mechanism 10 comprises a crystal holding plate 14, a rotating mechanism 13 and a supporting member 15. The crystal 11 is held on the crystal holding surface of the crystal holding plate 14. The support member 15 can rotate about a rotation shaft 12 that is perpendicular to a plane including the incident optical axis 33 and the outgoing optical axis 34. Further, it can move in parallel along the guide 19 parallel to the incident optical axis 33.

By rotating the support member 15, the incident angle of the incident optical axis 33 with respect to the crystal lattice plane of the crystal 11 can be changed. The rotating mechanism 13 uses the incident optical axis 33.
Also, the crystal holding plate 14 can be rotated about a rotation axis that is parallel to the plane including the output optical axis 34 and that is perpendicular to the crystal holding surface. Usually, the crystal lattice plane is parallel to the crystal holding plane. In this case, the axis of rotation is perpendicular to the crystal lattice plane.

The crystal holding mechanism 20 comprises a crystal holding plate 24, a rotating mechanism 23, and a supporting member 25. The crystal 21 is held on the crystal holding surface of the crystal holding plate 24. The support member 25 can be rotated about the rotation axis 22 perpendicular to the plane including the incident optical axis 33 and the outgoing optical axis 34, as in the case of the crystal holding mechanism 10. In addition, the output optical axis 3
It is translatable along a guide 29 which is parallel to 4.

The crystal holding mechanism 20 replaces the crystal 21 with the crystal 11.
It is arranged on the optical axis of the diffracted light from. Further, even if the incident angle of the incident optical axis 33 on the crystal lattice plane of the crystal 11 changes, the crystal 2
In order to prevent the optical axis 34 of the diffracted light from 1 from changing, it moves along the guide 29 and rotates around the rotating shaft 22. In this way, by interlocking the crystal holding mechanisms 10 and 20, the incident X-ray can be dispersed while the detector 31 is fixed.

FIG. 2 is a schematic sectional view of the crystal holding mechanism 10. The crystal holding mechanism 20 has the same structure. The support member 15 shown in FIG. 1 includes support members 15A to 15C. The support member 15B is fixedly attached to the support member 15A, and the support member 15C is attached to the support member 15B via the fine adjustment motor 16. The rotation mechanism 13 is attached to the support member 15C, and the crystal holding plate 14 is attached to the rotation mechanism 13.

Crystals 11A are formed on the crystal holding surface of the crystal holding plate 14.
And 11C are retained. Although not shown in the figure, crystals 11B and 11D are held in other regions of the crystal holding surface. FIG. 2 shows a case where the crystal 11A is arranged at a position blocking the incident optical axis 33. Fine tuning motor 1
6 is driven to move the support member 15C to the support member 1C.
5B can be translated in the direction normal to the crystal holding surface.

When the rotating mechanism 13 is driven, the crystal holding plate 1
4 rotates about a central axis perpendicular to the crystal holding surface. By rotating the crystal holding plate 14 on its own axis, the crystals arranged on the incident optical axis 33 can be exchanged. For example, when the four crystals 11A to 11D are held so as to be rotated four times around the central axis, the crystal holding plate 14 is set to 9
By rotating at 0 °, the crystal that diffracts X-rays can be exchanged.

The crystal holding surface does not necessarily have to be a flat surface, and may be any structure capable of holding the crystals 11A to 11D on a virtual plane. At this time, the central axis of rotation is configured to be perpendicular to this virtual plane.

When the crystal holding plate 14 is rotated by an angle smaller than 90 °, it is possible to move the irradiation point on the surface of one crystal to be irradiated with X-rays. When a crystal is damaged by X-ray irradiation, a single crystal can be effectively used by slightly moving the X-ray irradiation point. When the central axis of rotation is perpendicular to the crystal lattice plane, the distance between the crystal lattice planes does not change even if the X-ray irradiation point is moved, so that the action of diffracting X-rays does not change.

The rotating mechanism 13 is composed of, for example, an ultrasonic motor. Since the ultrasonic motor is smaller and lighter than a DC motor or the like, it is possible to reduce the size and weight of the entire spectrometer. Further, when the power supply to the ultrasonic motor is stopped, the brake is automatically applied to the crystal holding plate 14
Is fixed. After the adjustment so that the lattice planes of the crystals 11 and 14 are parallel to each other, the power supply to the ultrasonic motor can be stopped, so that power saving can be expected.

FIG. 3 is a perspective view showing another example of the structure of the crystal holding plate 14. 4 with the central axis of the crystal holding surface as the axis of rotation
The crystals 11A to 11C are respectively held at three places among the four places to be rotated. In the remaining one,
A through hole 17 is formed. When the crystal holding plate 14 is rotated to stop at the position where the through hole 17 is arranged on the incident optical axis 33, the incident X-ray is not diffracted and goes straight on.
By detecting this straight traveling light, the optical axis of the incident X-ray can be adjusted regardless of the position where the crystal is installed.

After the optical axis of the incident X-ray is adjusted, the crystal is placed on the optical axis and the optical axes of the diffracted light and the emitted light are adjusted, so that the optical axis of the whole is relatively easily adjusted. It will be possible.

In the above embodiment, the case where four crystals are held in the crystal holding plate and the case where a through hole is provided at one place have been described, but the number of crystals held in the crystal holding plate is not limited to four. For example, the crystals may be held at the positions to be rotated six times, or the crystals may be arranged in a ring around the center of the crystal holding surface.

The plurality of crystals held on the crystal holding surface may be crystals of the same kind or two or more kinds of crystals. By holding a plurality of crystals of the same type, if the crystal surface is damaged, it can be easily replaced with a new crystal. If two or more kinds of crystals are held, they can be easily replaced with crystals having different crystal plane intervals. By changing the distance between the crystal planes, it becomes possible to disperse X-rays in a wider wavelength range than in the case where the distance between the crystal faces is fixed.

In the above-mentioned embodiment, the embodiment of the present invention has been described by taking the two-crystal spectroscope as an example, but the present invention can also be applied to a crystal spectroscope using only one crystal. Further, by replacing the crystal used in the above-mentioned embodiment with a diffractive member such as a multilayer film that diffracts electromagnetic waves, the present invention can be applied not only to the crystal spectroscope but also to other spectroscopes utilizing the diffraction phenomenon.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0032]

As described above, according to the present invention,
By rotating the diffractive member holding plate about its own axis, the diffractive member that radiates incident electromagnetic waves can be easily replaced. Further, by moving the irradiation point of the incident electromagnetic wave within the surface of one diffractive member, the diffractive member can be effectively used. By providing a through-hole in a part of the diffractive member holding plate and transmitting an incident electromagnetic wave, the optical axis can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a double crystal spectrometer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an outline of the crystal holding member shown in FIG.

FIG. 3 is a perspective view showing an outline of the crystal holding plate shown in FIG.

FIG. 4 is a schematic diagram of a double crystal spectrometer according to a conventional example.

[Explanation of symbols]

 10, 20 Crystal holding mechanism 11, 21 Crystal 12, 22 Rotating shaft 13, 23 Rotating mechanism 14, 24 Crystal holding plate 15, 25 Support member 16 Fine adjustment motor 17 Through hole 19, 29 Guide 31 X-ray detector 33 Incident Optical axis 34 Emission optical axis 50, 60 Crystal holding member 51A to 51D, 61A to 61D Crystal 55 Incident optical axis 56 Emission optical axis

Claims (5)

[Claims] 1. A diffractive member holding plate, which holds a diffractive member for diffracting an incident electromagnetic wave on a virtual plane such that a diffractive surface of the diffractive member and an incident optical axis of the incident electromagnetic wave intersect obliquely, A spectrometer having a rotation mechanism that is orthogonal to a plane and rotates the diffraction member holding plate about a rotation axis that does not pass through the intersection of the virtual plane and the incident optical axis. 2. The spectroscope according to claim 1, wherein the diffractive member holding plate has a through hole that allows the incident electromagnetic wave to pass therethrough. 3. The spectroscope according to claim 1, wherein the rotating mechanism rotates the diffraction member holding plate by an ultrasonic motor. 4. The incident electromagnetic wave is an X-ray, and the diffractive member is a member having a crystal structure.
The spectroscope according to any one of 3 above. 5. Another diffractive member for diffracting the incident electromagnetic wave is further provided such that the diffractive surface of the other diffractive member and the optical axis of the diffracted light of the incident electromagnetic wave by the diffractive member intersect at an angle. Another diffractive member holding plate held on a virtual plane, the other diffraction about the rotation axis that is orthogonal to the other virtual plane and does not pass through the intersection of the other virtual plane and the optical axis of the diffracted light. The spectrometer according to any one of claims 1 to 4, further comprising another rotation mechanism that rotates the member holding plate.