JPH10106799A - Radiation light beam line device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the irradiation range of a monochromic radiation light beam to an object without lengthening the distance between a spectral element and the object. SOLUTION: The scattering of a radiation light beam S to be emitted to a spectral element 22 is suppressed with a front mirror 21 having a parabolioidally curved concave reflecting surface, and the spectral element 22 which disperses an electromagnetic wave in an X-ray region in which a radiation light beam S is contained as a monochromic radiation light beam X1 is held so that a crystal surface 26 is curved in a convex state, and thereby, the dimension in the progressing direction of the radiation light beam S of the spectral element 22 is made small, the Darwin width of the spectral element is enlarged, and the enlarging ratio in the progressing direction of the beam cross section of the monochromic radiation light beam X1 emitted from the spectral element 22 is made large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation beam line device.

[0002]

2. Description of the Related Art When an electron moving at a speed close to the speed of light is bent by a magnetic field or an electric field, an electromagnetic wave (light) called a radiation is emitted in a tangential direction of an electron orbit.

FIG. 4 shows an example of a synchrotron radiation generating means, wherein 1 is a linear accelerator, which comprises an electron generator 2 for emitting electrons (charged particles) e, and one end having an electron. A straight tubular acceleration duct 3 connected to the generator 2;
A high-frequency accelerator 4 is provided to apply high frequency to the electrons e moving inside the acceleration duct 3 to accelerate the electrons e.

[0004] The other end of the acceleration duct 3 is connected to one end of a curved tubular deflecting duct 5.
A bending electromagnet 6 is provided to bend the trajectory of the electron e moving inside.

[0005] Reference numeral 7 denotes an electron storage ring. The electron storage ring 7 has an endless duct 8 for forming an orbit of electrons e. The other end of the deflection duct 5 is connected.

The bending portion of the endless duct 8 is provided with a deflecting electromagnet 9 for bending the trajectory of the electron e moving inside the endless duct 8. A high-frequency accelerator 10 is provided for applying a high frequency to the electrons e moving inside and accelerating the electrons e.

[0007] Further, in a curved portion at a required portion of the endless duct 8, a radiation light beam S emitted by bending the traveling direction of the electron e moving at a speed close to the speed of light in the curved portion is provided with an endless beam. One end of a beam line 11 for leading to the outside of the duct 8 is connected, and the other end of the beam line 11 is provided with an experimental device 12 for performing an experiment using the radiation light beam S as an irradiation light source.

When the radiation light beam S is emitted by the radiation light generating means shown in FIG. 4, the interior of the acceleration duct 3, the deflection duct 5, the endless duct 8, and the beam line 11 is depressurized to an ultra-high vacuum state. After the state in which the electrons e can move at a speed close to the speed of light, the electrons e are emitted from the electron generator 2.

The electrons e emitted from the electron generator 2 are:
The beam is accelerated by the high-frequency accelerator 4, and further enters the endless duct 8 by being bent by the bending electromagnet 6.

The electron e incident on the endless duct 8 is accelerated by the high-frequency accelerator 10 and its trajectory is bent at each bending portion by the bending electromagnet 9, whereby the tangent of the electron e to the trajectory of the electron e is obtained. A radiation light beam S is emitted in the direction.

A radiation light beam S emitted from a predetermined curved portion of the endless duct 8 enters a test device 12 via a beam line 11.

The radiated light beam S contains an electromagnetic wave having a wavelength ranging from the visible region to the X-ray region. In recent years, the radiated light beam S generated by the radiated light generating means as shown in FIG. It has been studied to spectrally disperse and use it as an irradiation light source for angiography (angiography / cardiovascular imaging).

On the other hand, the emitted light beam S generated by the emitted light generating means as shown in FIG. 4 is divergent light whose beam cross-section is enlarged in the traveling direction with the orbit of the electron e as a light emitting point. As a means for dispersing electromagnetic waves in the X-ray region from S, a synchrotron radiation beam line device as shown in FIG. 3 has been proposed.

The synchrotron radiation beam line apparatus shown in FIG. 3 has a front mirror 14 having a concave reflecting surface 13 which is parabolically curved.
And a spectroscopic element 17 formed by processing a single crystal such as silicon (Si) or germanium (Ge) having a characteristic of dispersing electromagnetic waves in the X-ray region such that the element surface 15 and the crystal plane 16 form an asymmetric angle of a predetermined angle. And inside the beam line.

The front mirror 14 is arranged so that the radiation light beam S can enter the concave reflection surface 13 and can emit the radiation light beam S from the concave reflection surface 13 as parallel light.

The spectroscopic element 17 disperses electromagnetic waves in the X-ray region included in the emitted light beam S by the asymmetrical reflection, in which the emitted light beam S emitted from the front mirror 14 can be incident on the element surface 15. It is arranged so as to emit a monochromatic radiation light beam X0 whose beam cross section expands in the traveling direction.

Further, the front mirror 14 and the spectral element 17
Is a holder 1 formed of a material having high thermal conductivity such as copper-free oxide and having a cooling medium flow path (not shown) therein.
8 and 19 respectively.

In the synchrotron radiation beam line apparatus shown in FIG. 3, when dispersing electromagnetic waves in the X-ray region from the synchrotron radiation beam S, the cooling medium must be continuously passed through the cooling medium flow paths of the holders 18 and 19. Thus, the emitted light beam S is emitted from the emitted light generating means (see FIG. 4) to the concave reflection surface 13 of the front mirror 14 while suppressing the thermal deformation of the front mirror 14 and the spectroscopic element 17.

The radiated light beam S incident on the concave reflection surface 13 of the front mirror 14 is emitted from the front mirror 14 as parallel light directed toward the element surface 15 of the spectral element 17, thereby entering the spectral element 17. A decrease in the intensity (density) of the power radiation beam S is suppressed.

The radiated light beam S emitted from the front mirror 14 enters the crystal plane 16 via the element surface 15 of the spectroscopic element 17, and the X-rays contained in the radiated light beam S from the spectroscopic element 17. The electromagnetic wave in the region is emitted as a monochromatic radiation light beam X0 whose beam cross section expands in the traveling direction,
The irradiation target is irradiated with the monochromatic radiation light beam X0.

[0021]

In the synchrotron radiation beam line apparatus shown in FIG. 3, it is necessary to irradiate a monochromatic radiant light beam X0 emitted from the spectral element 17 of the synchrotron radiation beam line apparatus over a wide range. By increasing the size of the spectroscopic element 17 with respect to the traveling direction of the radiation light beam S or by increasing the interval between the spectroscopic element 17 and the irradiation target, the beam of the monochromatic radiation light beam X0 incident on the irradiation target is increased. The cross section will be enlarged.

However, there is a limit in increasing the size of the spectroscopic element 17 with respect to the traveling direction of the radiated light beam S, and if the distance between the spectroscopic element 17 and the irradiation target is increased, the radiated light generating means (FIG. (See FIG. 3) and the radiation beam line device (see FIG. 3), and the area of the building equipment where the irradiation target is to be arranged tends to increase according to the irradiation range of the monochromatic radiation light beam X0 in the irradiation target.

The present invention has been made in view of the above circumstances, and without increasing the distance between the spectroscopic element and the irradiation target,
It is an object of the present invention to provide a radiation beam line device capable of irradiating an irradiation target with a monochromatic radiation light beam over a wide range.

[0024]

According to a first aspect of the present invention, there is provided a synchrotron radiation beam line apparatus having a concave reflection surface, and having a concave reflection surface incident thereon. A front mirror 21 that reflects the beam S so as not to diverge, and an electromagnetic wave in the X-ray region from the radiated light beam S that is kept in a state where the crystal surface 26 is convexly curved and enters the crystal surface 26 from the front mirror 21. And a single-crystal light-splitting element 22 that splits the light into a monochromatic radiation light beam X1.

Further, in the synchrotron radiation beam line device according to the second aspect of the present invention, the concave reflecting surface 20 parabolically curved is provided.
A front mirror 21 for reflecting the radiated light beam S incident on the concave reflecting surface 20 as parallel light, and a crystal surface 26 held in a convexly curved state, and the front mirror 21 A monocrystalline spectroscopic element 22 that splits an electromagnetic wave in the X-ray region from the incident radiation light beam S and emits a monochromatic radiation light beam X1.

In any one of the first and second embodiments of the present invention, the divergence of the radiation light beam S to be incident on the spectroscopic element 22 is controlled by the front mirror 21 having the concave reflection surface 20. Suppressed by
The spectroscopic element 22 for dispersing the electromagnetic wave in the X-ray region including the emitted light beam S as a monochromatic emitted light beam X1
Is held in a convexly curved state, thereby reducing the size of the spectroscopic element 22 with respect to the traveling direction of the emitted light beam S, increasing the Darwin width of the spectroscopic element 22, and exiting from the spectroscopic element 22. The rate at which the beam cross section of the monochromatic radiation light beam X1 expands in the traveling direction is increased.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an embodiment of a radiation light beam line device according to the present invention. The radiation light beam line device comprises a front mirror 21 having a parabolically curved concave reflection surface 20 and a front mirror 21. , Silicon (Si) or germanium (G) having a characteristic of dispersing electromagnetic waves in the X-ray region.
e) and a dispersive element 22 made of a single crystal, etc., are provided in a beam line.

The front mirror 21 is arranged such that the radiation light beam S can be incident on the concave reflection surface 20 and can emit the radiation light beam S from the concave reflection surface 20 as parallel light.

The spectroscopic element 22 is supported by the holder 24 so that the crystal surface 26 is curved in a convex shape, and is formed by a radiated light beam S incident on the crystal surface 26 from the front mirror 21 via the element surface 25 by X. It is arranged so as to emit a monochromatic radiation light beam X1 whose beam cross-section is enlarged in the traveling direction by dispersing the electromagnetic waves in the line region.

The front mirror 21 and the spectral element 22
Is a holder 2 made of a material having high thermal conductivity such as copper-free oxide and having a cooling medium flow path (not shown) inside.
3 and 24 respectively.

In the radiation beam line apparatus shown in FIG. 1, when the electromagnetic waves in the X-ray region are separated from the radiation light beam S, the cooling medium must be continuously passed through the cooling medium flow paths of the holders 23 and 24. Accordingly, the emitted light beam S is emitted from the emitted light generation means (see FIG. 3) to the concave reflection surface 20 of the front mirror 21 while suppressing the thermal deformation of the front mirror 21 and the spectral element 22.

The radiated light beam S incident on the concave reflection surface 20 of the front mirror 21 is emitted from the front mirror 21 as parallel light directed toward the element surface 25 of the spectral element 22, thereby entering the spectral element 22. A decrease in the intensity (density) of the power radiation beam S is suppressed.

The radiated light beam S emitted from the front mirror 21 enters the crystal plane 26 via the element surface 25 of the spectroscopic element 22, and the X-rays contained in the radiated light beam S from the spectroscopic element 22. The electromagnetic wave in the region is emitted as a monochromatic radiation light beam X1 whose beam cross section expands in the traveling direction,
The irradiation target is irradiated with the monochromatic radiation light beam X1.

In the synchrotron radiation beam line apparatus shown in FIG. 1, a spectroscopic element 22 for dispersing an electromagnetic wave in the X-ray region including the synchrotron radiation beam S as a monochromatic synchrotron radiation beam X1 has a crystal surface 26 curved in a convex shape. Since it is supported by the holder 24 so as to satisfy the following condition, compared with the spectroscopic element 17 (see FIG. 3) in the conventionally proposed synchrotron radiation beam line device,
The ratio of the beam cross section of the monochromatic radiation light beam X1 emitted from the spectroscopic element 22 in the traveling direction becomes smaller as the size of the monochromatic radiation light beam X1 emitted from the spectroscopic element 17 decreases. Is larger than the monochromatic radiation light beam X0.

Further, by bending the dispersive crystal 22, the dispersive crystal 22 becomes non-uniform, and the Darwin width of the single crystal applied to the dispersive element 22 increases.

The Darwin width is defined as a flat portion (a reflection intensity curve having a top hat-shaped profile representing the relationship between the reflection intensity of a single crystal and the incident angle θ of a light beam with respect to the single crystal) shown in FIG. As the Darwin width is increased, the intensity of the monochromatic light beam X1 emitted from the spectral element 22 becomes higher than the intensity of the monochromatic emitted light beam X0 emitted from the spectral element 17.

Therefore, in the radiation beam line apparatus shown in FIG. 1, it is possible to irradiate the irradiation target with the monochromatic radiation light beam X1 having high intensity over a wide range without increasing the distance between the spectroscopic element 22 and the irradiation target. And a synchrotron radiation generating means (see FIG. 3) and a synchrotron beam line device (FIG. 1).
(See FIG. 2) and the area of the building equipment where the irradiation target is to be arranged can be reduced as compared with the case where the conventionally proposed synchrotron radiation beam line device (see FIG. 2) is applied.

It should be noted that the radiation beam line device of the present invention is not limited to the above-described embodiment, but it is needless to say that various changes can be made without departing from the spirit of the present invention.

[0040]

As described above, in any of the radiation beam line devices according to the first and second aspects of the present invention, the divergence of the radiation light beam S to be incident on the spectral element 22 is concavely reflected. The spectroscopic element 22 for suppressing the electromagnetic wave in the X-ray region including the emitted light beam S as a monochromatic emitted light beam X1 is suppressed by the front mirror 21 having the surface 20 and the crystal surface 26 is curved in a convex shape. As a result, the dimension of the spectral element 22 in the traveling direction of the radiation light beam S can be reduced, and the beam cross section of the monochromatic radiation light beam X1 emitted from the spectral element 22 expands in the traveling direction. Increase the rate of
Further, since the Darwin width of the spectroscopic element 22 is increased, it is possible to irradiate the irradiation target with a high-intensity monochromatic radiation light beam X1 over a wide range without increasing the distance between the spectroscopic element 22 and the irradiation target. An excellent effect that the area of the building equipment where the light generating means and the radiation light beam line device are installed and the irradiation target is to be arranged can be reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of an embodiment of a synchrotron radiation beam line device according to the present invention.

FIG. 2 is a graph showing a Darwin curve.

FIG. 3 is a conceptual diagram showing an example of a conventionally proposed radiation light beam line device.

FIG. 4 is a conceptual diagram illustrating an example of a radiation light generating unit.

[Explanation of symbols]

 Reference Signs List 20 concave reflecting surface 21 front mirror 22 spectral element 26 crystal plane S radiation light beam X1 monochromatic radiation light beam

Claims (2)

[Claims] A front mirror (21) having a concave reflecting surface (20) and reflecting so as not to diverge a radiation light beam (S) incident on the concave reflecting surface (20); and a crystal surface (26). ) Is held in a convexly curved state and the front mirror (21)
From the radiation light beam (S) incident on the crystal plane (26), the electromagnetic wave in the X-ray region is separated to produce a monochromatic radiation light beam (X1)
And a single crystal spectroscopic element (22) that emits light. 2. A radiation beam (S) having a parabolically curved concave reflecting surface (20) and incident on said concave reflecting surface (20).
Mirror (21) that reflects the light as parallel light, and a radiation light beam (S) whose crystal surface (26) is held in a convexly curved state and is incident on the crystal surface (26) from the front mirror (21). A) a monocrystalline spectroscopy element (22) that emits a monochromatic radiation light beam (X1) by dispersing an electromagnetic wave in the X-ray region from the X-ray region.