JP3593605B2 - X-ray spectroscopy element - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an X-ray spectroscopy device capable of generating divergent X-rays.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in X-ray diffraction analysis, as shown in FIG. 2, an X-ray emitted from a linear X-ray source (linear focus on a target of an X-ray tube) 20 is emitted using a divergence slit 22. The divergence angle γ is narrowed down so as to irradiate the sample surface 23a of the sample 23 as widely as possible.
[0003]
[Problems to be solved by the invention]
Here, the divergence angle γ is a minute angle of, for example, about 1 degree, and uses only a small part 21 of the X-rays emitted from the X-ray source 20, so that the intensity of the X-rays 21 irradiated on the sample surface 23a is However, accurate analysis is sometimes not enough. On the other hand, when the divergence angle γ is increased, the parallelism of the X-rays 21 applied to the sample surface 23a is weakened, and the analysis becomes inaccurate.
[0004]
The present invention has been made in view of the above-described conventional problems, and has as its object to provide an X-ray spectroscopic element capable of generating a divergent X-ray having a small divergence angle and sufficient intensity.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the X-ray spectroscopy element according to claim 1 is an X-ray spectroscopy element in which a multilayer film is deposited on a substrate. First, x ² / a ² −y ² / b with respect to orthogonal coordinates xyz. A part on one side of the focal point on one of the two hyperbolic cylindrical surfaces represented by ² = 1 is defined as a diffraction surface. Then, at an arbitrary point on the diffraction surface, the periodic length of the multilayer film is surrounded by the hyperboloid surface to which the diffraction surface belongs out of two linear focal points extending in the z direction of the two-lobe hyperboloid surface. It is set so that X-rays of a wavelength to be diffracted, which are emitted perpendicularly in the z direction from one focal point, are diffracted by the diffraction surface and diverged as if emitted perpendicularly in the z direction from the other focal point. And
[0006]
According to the X-ray spectroscopy element of the first aspect, the X-rays are emitted from a linear X-ray source placed at one focal point, and are diffracted by receiving X-rays narrowed to a divergence angle of about 2 to 5 degrees, for example. Since the light is diverged as if emitted from the other focal point at a divergence angle of about 1 degree, a divergent X-ray having a small divergence angle and sufficient intensity can be generated.
[0007]
The X-ray spectroscopy element according to claim 2 is an X-ray spectroscopy element in which a multilayer film is deposited on a substrate. First, x ² / a ² −y ² / b ² −z ² / b ² = xyz of the orthogonal coordinates xyz. A part on the side surrounding the focal point in one of the two hyperboloids of revolution represented by 1 is defined as a diffraction surface. Then, at any point on the diffraction surface, the periodic length of the multilayer film is emitted from one focal point surrounded by the rotation hyperboloid to which the diffraction surface belongs out of two point-like focal points of the two-leaf rotation hyperboloid. X-rays of a wavelength to be diffracted are set to be diffracted on a diffraction surface and diverged as if they were emitted from the other focal point.
[0008]
According to the X-ray spectroscopic element of the second aspect, the light is emitted from a point-like X-ray source placed at one focal point, and is diffracted by receiving X-rays whose divergence angle is, for example, about 2 to 5 degrees, Since the light is diverged as if emitted from the other focal point at a divergence angle of about 1 degree, a divergent X-ray having a small divergence angle and sufficient intensity can be generated.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the X-ray spectroscopy device according to the first embodiment of the present invention will be described. As shown in FIG. 1, this X-ray spectroscopy element 1 has the same structure as that of X-ray spectroscopy element 1 in which a multilayer film 3 is deposited on a substrate 2. (Forward), one of two hyperbolic cylindrical surfaces H ₁ , H ₂ extending in the direction perpendicular to the plane of the paper represented by x ² / a ² −y ² / b ² = 1, on the side surrounding the focal point F ₁ at H ₁ . A part is a diffraction surface 1a. The period length _{d 0} of the multilayer film 3, at any point on the diffraction surface 1a, the hyperbolic cylindrical surface _H 1 of the 2 leaf, linear bifocal _F 1 extending in the z direction of _{H 2, F 2} from the one focal point F ₁ of the diffraction surface 1a is surrounded by the hyperbolic cylindrical surface H ₁ belonging perpendicular to the z-direction (e.g., along the paper surface) X-ray 4A of wavelengths to be diffracted emitted, the 4B, the diffraction of and diffracted by the surface 1a, it is configured so as to diverge from the other focal point F ₂ as emitted perpendicular to the z-direction. Such an artificial multilayer film 3 can be formed, for example, by alternately depositing a tungsten layer and a silicon layer, and the sum of the thicknesses of one set of the tungsten layer and the silicon layer is equal to the period length d _{0 of the} multilayer film 3. It becomes. In FIG. 1, only three sets of layers of the multilayer film 3 are shown for ease of illustration.
[0010]
That is, the multilayer film 3, at any point on the diffraction surface 1a forming part of the hyperbolic cylindrical surface H _1, the wavelength λ emitted from one of the linear X-ray source placed at the focal F ₁ X The line 4 is set so as to be received at an incident angle θ and diffracted and reflected at a reflection angle θ of the same angle. Here, the shape of the diffraction surface 1a, since the position of the focal point F ₁ is known, the incident angle (reflection angle) at each arbitrary point on the diffraction surface 1a theta geometrically unambiguously determined, The diffraction Since the wavelength λ of the X-ray 4 to be obtained is also known, the so-called d value that characterizes the period length of the multilayer film 3 satisfies the Bragg condition of the following equation (1).
[0011]
2d sin θ = nλ (n is a positive integer in the diffraction order) (1)
[0012]
Sin θ in the equation (1) is derived from the equation of the hyperbolic cylinder surface indicating the shape of the diffraction surface 1a, and when this is substituted into the expression (1) and n = 1, the d value becomes At an arbitrary point P (x ₁ , y ₁ , z ₁ ) of the following equation (2).
[0013]
_{^{d = λ (x 1 2 +}} y 1 2 -a 2 + b 2) 1/2 / 2b ... (2)
[0014]
Since the d value can be controlled by changing conditions such as a deposition time and masking when the multilayer film 3 is formed on the substrate 2, the X-ray spectroscopic element 1 of the first embodiment has the focus F ₁ described above. It can be manufactured by finding and adjusting the conditions for forming the multilayer film 3 that causes a diffraction phenomenon of diffracting the X-rays 4 having a wavelength λ emitted from the multilayer film 3.
[0015]
However, it is known that this d value does not strictly coincide with the actual period length d ₀ of the multilayer film 3 due to the refraction phenomenon of X-rays, and has a relationship of the following equation (3).
[0016]
d = d ₀ [1- (2δ−δ ² ) / sin ² θ] ^1/2 (3)
[0017]
That is, as described above, if the X-ray spectroscopy device 1 of the first embodiment is manufactured by adjusting the formation conditions of the multilayer film 3 so as to cause a desired diffraction phenomenon, the actual period length d of the multilayer film 3 can be obtained. ₀ satisfies Expression (3). In the expression (3), δ is a refractive index determined by the composition of the multilayer film 3 and the like.
[0018]
According to the X-ray spectroscopy device 1 of the first embodiment, as shown in FIG. 1, the light is emitted from a linear X-ray source placed at _one focal point F1 and has a divergence angle の of, for example, about 2 to 5 degrees. diffracted by receiving X-rays 4 that focused on, it is possible to diverge as emitted from the other focal point F ₂ by 1 degrees of divergence angle gamma. That is, for example, when irradiating the sample with X-rays having a divergence angle γ of about 1 degree, the angle at which the X-rays emitted from the X-ray source are narrowed may be about 2 to 5 degrees instead of 1 degree. X-rays emitted from the source can be used with an efficiency of about 2 to 5 times that of the related art. Therefore, a divergent X-ray with a small divergence angle γ and sufficient intensity can be generated.
[0019]
Next, an X-ray spectroscopy device according to a second embodiment of the present invention will be described. As shown in FIG. 1, this X-ray spectroscopy element 11 has a structure in which a multilayer film 13 is deposited on a substrate 12, first, x ² / a ² −y ² / b with respect to the orthogonal coordinates xyz. the part of the side surrounding the focal point _{F 3} in one of ² -z ² / ^b 2 = 1 rotation of the 2 leaf represented by hyperboloid _H 3, _{H 4} and the diffractive surface 11a. That is, in the X-ray monochromator 11 of the second embodiment, a hyperbola indicated by a two-dot chain line in FIG. 1, a portion of the hyperboloid of revolution H ₃ is rotated about the x-axis and the diffraction surface 11a, FIG. 1 is a sectional view. Then, at an arbitrary point on the diffraction plane, the periodic length d ₀ of the multilayer film 13 is the diffraction plane 11a among the point-like bifocals F ₃ , F ₄ of the two-leaf rotation hyperboloids H ₃ , H _4. X-ray 14A of wavelengths to be diffracted emitted from the focal point F ₃ of the one that is surrounded by the rotating hyperboloid H ₃ which belongs to 14B, and diffracted by the diffraction surface 11a, to diverge as emitted from the other focal point F ₄ It is set as follows.
[0020]
That is, the multilayer film 13, the rotation at any point on the diffraction surface 11a forming a part of the hyperboloid H _3, X-rays of a wavelength λ emitted from one point-like X-ray source placed at the focal F ₃ 14 is set to be received at an incident angle θ and diffracted and reflected at a reflection angle θ of the same angle. Here, the shape of the diffraction surface 11a, since the position of the focal point F ₃ is known, the incident angle (reflection angle) at each arbitrary point on the diffraction surface 11a theta geometrically unambiguously determined, The diffraction Since the wavelength λ of the X-rays 14 to be obtained is also known, the so-called d value characterizing the period length of the multilayer film 13 is the same as the X-ray spectroscopic element 1 of the first embodiment, and the Bragg condition of the above equation (1) is used. Meet.
[0021]
Sin θ in the expression (1) is derived from the expression of the hyperboloid of revolution showing the shape of the diffraction surface 11a, and when this is substituted into the expression (1) and n = 1, the d value on the diffraction surface is At an arbitrary point P (x ₁ , y ₁ , z ₁ ), it is represented by the following equation (4).
[0022]
_{^{d = λ (x 1 2 +}} y 1 2 + z 1 2 -a 2 + b 2) 1/2 / 2b ... (4)
[0023]
X-ray monochromator 11 of the second embodiment also, by adjusting found a forming condition of the multilayer film 13 that causes a diffraction phenomenon that diffracts X-rays 14 of a wavelength λ that has been emitted from the focal point F _3, to prepare be able to. However, similarly to the X-ray spectroscopy device 1 of the first embodiment, the d value does not exactly match the actual period length d ₀ of the multilayer film 13 due to the refraction phenomenon of X-rays, and the d-value is given by the formula (3) ) Have a relationship. That is, if the X-ray spectroscopy element 11 of the second embodiment is manufactured by adjusting the forming conditions of the multilayer film 13 so as to cause a desired diffraction phenomenon, the actual period length d ₀ of the multilayer film 13 is expressed by the following equation. (3) is satisfied.
[0024]
According to the X-ray monochromator 11 of the second embodiment, one emitted from a point-like X-ray source placed at the focal F ₃ for example twice to X-ray was focused on ψ divergence angle of about 5 degrees 14 receiving diffracted, it is possible to dissipate as emitted from the other focal point F ₄ in 1 degrees of divergence angle gamma. That is, for example, when irradiating the sample with X-rays having a divergence angle γ of about 1 degree, the angle at which the X-rays emitted from the X-ray source are narrowed may be about 2 to 5 degrees instead of 1 degree. X-rays emitted from the source can be used with an efficiency of about 2 to 5 times that of the related art. Therefore, a divergent X-ray with a small divergence angle γ and sufficient intensity can be generated.
[0025]
【The invention's effect】
As described above, according to the present invention, a divergent X-ray having a small divergence angle and sufficient intensity can be generated.
[Brief description of the drawings]
FIG. 1 is a front view or a sectional view showing an X-ray spectroscopy element according to a first or second embodiment of the present invention.
FIG. 2 is a perspective view showing a conventional X-ray diffraction analyzer.
[Explanation of symbols]
1, 11 ... X-ray monochromator, 1a, 11a ... diffraction surface, 2, 12 ... substrate, 3,13 ... multilayer, 4, 14 ... X-ray wavelength to be diffracted emitted from one focal point, _{d 0} ... Period length of the multilayer film, F ₁ , F ₂ … linear focus, F ₃ , F ₄ … point focus, H ₁ , H ₂ … hyperboloid, H ₃ , H ₄ … rotation hyperboloid

Claims (2)

In an X-ray spectroscopy device having a multilayer film deposited on a substrate,
With respect to the rectangular coordinates xyz, a part of one of the two hyperboloidal surfaces of the two leaves represented by x ² / a ² −y ² / b ² = 1 on the side surrounding the focal point is defined as a diffraction surface,
At any point on the diffraction surface, the periodic length of the multilayer film is one of two linear focal points extending in the z direction of the two-lobe hyperbolic cylinder surface and surrounded by the hyperbolic cylinder surface to which the diffraction surface belongs. X-rays of a wavelength to be diffracted, which are emitted perpendicularly in the z direction from the focal point, are diffracted by the diffraction surface, and are set to diverge as if emitted perpendicularly in the z direction from the other focal point. X-ray spectroscopy element. In an X-ray spectroscopy device having a multilayer film deposited on a substrate,
For rectangular coordinates ^xyz, and ^{x 2 / a 2 -y 2 /} b 2 -z 2 / b 2 = some diffractive surface on the side surrounding the focus in one of the hyperboloid of revolution of 2 leaf represented by 1,
At an arbitrary point on the diffraction surface, the periodic length of the multilayer film is different from the diffraction intensity emitted from one focal point surrounded by the rotation hyperboloid to which the diffraction surface belongs among the two point-like focal points of the two-lobe rotation hyperboloid. An X-ray spectroscopy element characterized in that X-ray spectroscopy elements are set to diffract an X-ray of a power wavelength by a diffraction surface and diverge as if emitted from the other focal point.

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