JP3739036B2 - X-ray small angle scattering system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an X-ray small angle scattering apparatus that measures changes in the intensity of scattered X-rays in a small angle region centered on the optical axis of incident X-rays.
[0002]
[Prior art]
Depending on the substance, scattered X-rays may be generated in a small angle region centered on the optical axis of incident X-rays, for example, an angle region of about 0 ° to 5 ° when X-rays are irradiated to the substance. For example, if fine particles of about 10 to 1000 mm or a non-uniform region having a size corresponding to this exists in the substance, diffuse scattering in the incident line direction, so-called center scattering occurs. This central scattering is independent of the internal structure of the particle and spreads as the particle becomes smaller.
[0003]
The above scattering exists regardless of crystalline or amorphous, and is observed in a small angle region where the scattering angle, that is, the angle from the optical axis of incident X-rays is about 0 ° to 5 °. In addition to the above-mentioned center scattering, Bragg reflection when the lattice spacing is very large, such as protein crystals, and crystalline and amorphous are periodically arranged in the fiber sample in the small angle region. X-ray diffraction in the case of a so-called long-period structure is observed. Including the center scattering, Bragg reflection and X-ray diffraction as described above, X-rays observed in a small angle region are generally called small angle scattering.
[0004]
The X-ray small angle scattering apparatus according to the present invention is an apparatus for measuring such small angle scattering. Since this X-ray small-angle scattering apparatus measures weak scattered X-rays generated from a sample, it is necessary to eliminate as much as possible parasitic scattering that lowers the resolution and the S / N ratio.
[0005]
Here, the resolution may be a small-angle resolution indicating how small a scattered X-ray can be measured and an angular resolution necessary to separate and measure adjacent diffraction lines. Then, both resolutions need to be kept high. Parasitic scattering refers to X-rays observed when a sample is removed from the X-ray measurement system, and is excited by diffuse scattering or white X-rays from optical elements exposed to the scattered X-rays. X-ray fluorescence and the like are considered to be the main cause.
[0006]
Conventionally, various types of X-ray small angle scattering devices are known in order to realize the above-described measurement with high accuracy. For example, as shown in FIG. 3, a so-called three-slit X-ray small angle scattering apparatus using three slits, a first slit 51, a second slit 52, and a third slit 53, is known. In this X-ray small angle scattering apparatus, the X-rays radiated from the X-ray source F are formed into a parallel X-ray beam using the first slit 51 and the second slit 52, and the parasitic generated by the second slit 52 The progress of scattered X-rays is blocked by the third slit 53, and the sample S is irradiated with X-rays excluding the parasitic scattered X-rays.
[0007]
Thus the parallel X-ray beam on the sample S is irradiated, scattered X-ray R _S is generated in small angle regions depending on the nature of the sample S, a two-dimensional X-ray detector 54 is exposed by the scattered X-ray The X-ray detector 54 forms an X-ray latent image corresponding to the scattered X-rays. After making this X-ray latent image visible, the crystal structure of the sample S is determined by observing the visible image.
[0008]
[Problems to be solved by the invention]
In the conventional 3-slit X-ray small angle scattering apparatus, each of the first slit 51, the second slit 52, and the third slit 53 is supported by an individual holder, and the sample S is also supported by a dedicated sample holder. .
[0009]
There is also known an X-ray small angle scattering apparatus in which the first slit 51, the second slit 52, and the third slit 53 are integrally supported by one holder and the sample S is supported by a dedicated sample holder. .
[0010]
In FIG. 3, a symbol E indicates a region where the parasitic scattered X-ray generated at the second slit 52 reaches the X-ray detector 54 without being blocked by the third slit 53. This region E is a so-called non-measurable region where the scattered X-rays that are the measurement target generated from the sample S cannot be read due to the influence of the parasitic scattered X-rays.
[0011]
In the conventional X-ray small angle scattering apparatus, the distance L0 between the third slit 53 and the sample S cannot be reduced due to the mechanical size of the sample holder, the slit holder, and the like. The fact that the distance L0 cannot be reduced means that the region E of the parasitic scattered X-ray that passes through the third slit 53 and reaches the X-ray detector 54 cannot be reduced. This means that the non-measurable area in the detector 54 becomes wide, and the wide area of the X-ray detector 54 cannot be the object of observation.
[0012]
In the meantime, in the Japanese Patent Application Laid-Open No. 09-119905, the applicant of the present application is concerned with the third slit, the sample, We proposed a structure that integrally supports However, what is mainly described in this document is a so-called transmission type X-ray small angle scattering apparatus, and it is difficult to divert the configuration shown here to a reflection type X-ray small angle scattering apparatus as it is.
[0013]
The present invention has been made in view of the above problems, and an object of the present invention is to reduce a non-measurable region generated due to parasitic scattered X-rays in a reflective X-ray small angle scattering apparatus. .
[0014]
[Means for Solving the Problems]
To achieve the above Symbol purpose of, X-ray small-angle scattering apparatus according to the present invention includes a first slit and a second slit for shaping the X-rays emitted from the X-ray source into a parallel X-ray beam, said second slit A third slit that guides the parallel X-ray beam to the sample while preventing the progress of the parasitic scattered X-rays generated at the sample, and an X-ray detection means for detecting the measured scattered X-rays generated from the sample, The first slit and the second slit are arranged at a low angle with respect to the sample so that diffracted X-rays can be generated in the reflection state in the sample, and the X-ray detection means diffracts in the reflection state from the sample. In the X-ray small angle scattering apparatus arranged at a position where X-rays can be detected, the third slit is open to the outside at the side edge of the X-ray shielding portion that shields the progress of the X-ray and the X-ray shielding portion. With X-ray passage holes Has a third further a slit support means for supporting said third slit, said third slit support means, said third slits supports the third slit so that it can be pressed against the sample, said The three slits are arranged such that the side end where the X-ray passing hole is open to the outside is brought into close contact with the sample, and the X-ray shielding part protrudes from the sample.
[0015]
According to the X-ray small angle scattering apparatus of this configuration, the first slit and the second slit are arranged at a low angle position with respect to the sample so that diffracted X-rays can be generated in the reflected state in the sample, Since the X-ray detection means is disposed at a position where X-rays diffracted from the sample in a reflected state can be detected, a so-called reflection-type X-ray small angle scattering apparatus can be realized.
[0016]
In addition, the third slit is arranged so that the side edge where the X-ray passage hole is open to the outside adheres closely to the sample, and the X-ray shielding part protrudes from the sample. Compared with the conventional X-ray small angle scattering apparatus having a structure arranged away from the X-ray detector, the non-measurable area on the X-ray detector can be remarkably reduced. Therefore, a wide area of the X-ray detector can be used. Scattering measurements can be made.
[0017]
In the following, Oite the engagement Ru X-ray small angle scattering equipment to the present invention, the third slit relative to the specimen, it is desirable to disposed substantially at a right angle.
[0018]
In the following, Oite the engagement Ru X-ray small angle scattering equipment to the present invention, the X-ray passing holes of the third slit is preferably formed in a semicircular shape. According to this configuration, parasitic scattered X-rays generated from the second slit can be reliably blocked by the third slit.
[0019]
In the following, it engages Ru X-ray small angle scattering equipment to the invention further comprises a third slit support means for supporting said third slit, said third slit support means, said third slit presses the sample The third slit is supported so as to be able to do so. According to this configuration, the third slit can be accurately brought into close contact with the sample, so that the parasitic scattered X-rays from the second slit can be reliably shielded.
[0020]
In the following, the engagement Ru X-ray small-angle scattering apparatus in the present invention, the third slit supporting means, it is preferable that the third slit for supporting the third slit so as to be able to press the sample by its own weight. According to this configuration, a special device that applies force to the third slit is not required, and the structure is simplified. Further, it is possible to prevent unnecessary force from being applied to the sample.
[0021]
In the following, the engagement Ru X-ray small-angle scattering apparatus in the present invention, the third slit, said X-ray passing hole is arranged to be positioned to coincide with the X-ray incident point is desirable. According to this configuration, the third slit can be arranged at the most preferable position without blocking the progress of the scattered X-ray from the sample but blocking the progress of the parasitic scattered X-ray from the second slit.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of a small-angle X-ray scattering apparatus according to the present invention. This X-ray small angle scattering apparatus includes an X-ray source F that generates X-rays, a collimator 3 constituted by the first slit 1 and the second slit 2, and a downstream side of the collimator 3 (on the right side in the structure of FIG. 1). The sample support 4 is disposed, the third slit 6 is disposed so as to face the sample support 4, and the two-dimensional X-ray detector 7 is disposed on the downstream side of the sample support 4.
[0023]
The two-dimensional X-ray detector 7 is an X-ray detector that can capture X-rays in a plane, and can be constituted by, for example, an X-ray film, a storage phosphor, or the like. An X-ray film is a flat film that can be exposed to X-rays to form a latent image on the portion, and that can be developed by a development process. By observing this visible image visually, the incident position and intensity of X-rays contributing to the exposure of the X-ray film can be measured.
[0024]
On the other hand, the stimulable phosphor is an energy storage-type radiation detection element also called a stimulable phosphor, and a stimulable phosphor, for example, BaFBr: Er ²⁺ microcrystals, a flexible film, a flat film, The film is formed on the surface of another member by coating or the like. This storage phosphor is an object that can store X-rays and the like in the form of energy, and can emit the energy as light to the outside by irradiation of stimulating excitation light such as laser light.
[0025]
That is, when the stimulable phosphor is irradiated with X-rays or the like, energy is accumulated as a latent image inside the stimulable phosphor corresponding to the irradiated portion, and further, the stimulable phosphor such as laser light is emitted. When the excitation light is irradiated, the latent image energy is emitted to the outside as light. By detecting the emitted light with a phototube or the like, the diffraction angle and intensity of X-rays that contributed to the formation of the latent image can be measured. This stimulable phosphor has a sensitivity 10 to 60 times that of a conventional X-ray film, and further has a wide dynamic range of 10 ⁵ to 10 ⁶ .
[0026]
The 1st slit 1 and the 2nd slit 2 which comprise the collimator 3 are comprised by the pinhole, for example. Further, the diameter of the first slit 1 is, for example, about φ0.1 mm, and the diameter of the second slit 2 is, for example, about φ0.05 mm.
[0027]
In FIG. 1, the sample S to be measured is fixed to the tip of the sample support 4. The third slit 6 is fixed to the tip of an arm 9 extending from the third slit support device 8. The third slit support device 8 has a built-in mechanism that can move the arm 9 up and down. In particular, the lowering movement of the arm 9 toward the sample S is performed by its own weight. As a result, in FIG. 1, the third slit 6 presses the sample S by its own weight, and one end of the third slit 6 is placed in close contact with the surface of the sample S without any gap, that is, in contact.
[0028]
The third slit 6 has an X-ray passing hole 11 at the side edge that is in close contact with the sample S. In the present embodiment, the hole 11 is formed in a semicircular shape, and the diameter of the semicircle is larger than the pinhole diameter of the second slit 2, and is set to about φ0.15 to φ0.25 mm, for example. Further, the peripheral shape of the hole 11 is set so as to be slightly larger than the X-ray beam diameter at the incident point P of the X-rays that are regulated by the second slit 2 and enter the sample S. Portions other than the hole 11 of the third slit 6 function as an X-ray shield that does not allow X-rays to pass through.
[0029]
X-rays radiated from the X-ray source F are incident on the sample S at an incident angle θ expected by the first slit 1 and the second slit 2. The incident angle θ is set to an angle at which X-rays incident on the sample S can be diffracted by the sample S in a reflected state, and are set to a low angle, for example, 0.1 ° to 0.2 °. The two-dimensional X-ray detector 7 is arranged at a position where X-rays diffracted from the sample S in a reflected state can be detected.
[0030]
Since the X-ray small angle scattering apparatus of the present embodiment is configured as described above, in FIG. 1, the X-ray emitted from the X-ray source F is shaped into a parallel X-ray beam having a small diameter by the collimator 3 and is low. The light enters the sample S from the angle θ. At this time, in FIG. 2, the incident X-ray emitted from the second slit 2 passes through the hole 11 of the third slit 6 and enters the sample S.
[0031]
Since the hole 11 is formed to have a diameter slightly larger than the beam diameter of the incident X-ray beam at the incident point P, the parasitic scattered X-ray generated from the second slit 2 is prevented from advancing by the shielding portion of the third slit 6. Thus, the X-ray detector 7 is not reached, and therefore the X-ray detector 7 is exposed only by the scattered X-rays from the sample S to be measured without being disturbed by the parasitic scattered X-rays. Reference numeral 13 denotes a direct beam stopper for preventing an X-ray direct beam from entering the X-ray detector 7.
[0032]
Further, in the present embodiment, the third slit 6 is in close contact with the surface of the sample S at the side edge where the hole 11 is provided, and the shielding portion protrudes from the sample S in a direction perpendicular to or close thereto, so in FIG. The diffraction angle 2θ _L2 corresponding to the region E ′ of the parasitic scattered X-rays generated from the two slits 2 and passing through the third slit 6 and reaching the X-ray detector 7 is the same as that of the conventional apparatus shown in FIG. In this case, the diffraction angle 2θ _L1 corresponding to the region E is significantly narrower. As a result, a wide area of the X-ray detector 7 can be used as an area for detecting scattered X-rays from the sample S.
[0033]
(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
[0034]
For example, in the embodiment of FIG. 1, the third slit 6 is supported by the support device 8 so that it can be moved up and down, and can be lowered by its own weight. However, the third slit 6 can be lowered by a force other than its own weight. Further, the third slit 6 can be bonded to the surface of the sample S instead of being supported by a special support device.
[0035]
【The invention's effect】
As described above, according to the X-ray small angle scattering apparatus according to the present invention, the third slit makes the X-ray shielding portion close to the sample with the side edge where the X-ray passage hole is open to the outside. Is arranged so as to protrude from the sample, so that the non-measurable area on the X-ray detector is significantly smaller than that of a conventional X-ray small angle scattering apparatus having a structure in which the third slit is arranged away from the sample. Therefore, X-ray small angle scattering measurement can be performed using a wide area of the X-ray detector.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a small-angle X-ray scattering apparatus according to the present invention.
FIG. 2 is a diagram schematically showing an optical arrangement state of the X-ray small angle scattering apparatus of FIG. 1;
FIG. 3 is a diagram showing an example of a conventional X-ray small angle scattering apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st slit 2 2nd slit 3 Collimator 4 Sample support stand 6 3rd slit 7 X-ray detector 8 3rd slit support apparatus 9 Arm 11 X-ray passage hole

Claims (5)

A first slit and a second slit for shaping an X-ray emitted from an X-ray source into a parallel X-ray beam;
A third slit for guiding the parallel X-ray beam to the sample while preventing the progress of parasitic scattered X-rays generated in the second slit;
X-ray detection means for detecting measured scattered X-rays generated from the sample,
The first slit and the second slit are arranged at a low angle position with respect to the sample so that diffracted X-rays can be generated in a reflected state in the sample,
In the X-ray small angle scattering apparatus, the X-ray detection means is disposed at a position where X-rays diffracted from the sample in a reflected state can be detected.
The third slit has an X-ray shielding part that shields the progression of X-rays, and an X-ray passage hole formed to open to the outside at the side edge of the X-ray shielding part,
And further comprising third slit support means for supporting the third slit,
The third slit support means supports the third slit so that the third slit can press the sample.
The third slit is disposed so that the side end where the X-ray passage hole is open to the outside is brought into close contact with the sample, and the X-ray shielding portion protrudes from the sample. Small angle scattering device. According to claim 1, wherein the third slit for the sample, X-rays small-angle scattering apparatus characterized by being arranged at right angles. According to claim 1 or claim 2, wherein the X-ray passing holes of the third slit X-ray small-angle scattering apparatus characterized by being formed in a semicircular shape. 4. The method according to claim 1, wherein the third slit support means supports the third slit so that the third slit can press the sample by its own weight. X-ray small angle scattering device. In claims 1 one claim 4 Neu Zureka, said third slit, X-rays, wherein the X-ray passing hole is arranged to be positioned to coincide with the X-ray incident point Small angle scattering device.

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