JP3823146B2 - X-ray fluorescence analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescent X-ray analysis apparatus that performs fluorescent X-ray analysis of, for example, river water, blood, body fluid, semiconductor cleaning liquid and other liquid samples or fine solids.
[0002]
[Prior art]
Conventionally, when this type of sample is subjected to fluorescent X-ray analysis, it is known to support the sample with a polymer thin film having a small background in order to perform accurate analysis with as little scattered X-rays as possible. In the conventional apparatus shown in FIG. 5, the excitation (primary) X-ray B1 from the X-ray source 24 is irradiated to the sample S on the polymer thin film 2 provided in the holder H, and the fluorescence X generated from the sample S By detecting the line B2 with the detector 25, the sample S is analyzed in a small background in which the generation of scattered X-rays B4 is suppressed.
[0003]
A total reflection type X-ray fluorescence analyzer that performs X-ray fluorescence analysis of a sample with a small background is also known. In this device, primary X-rays from an X-ray source are incident on a sample surface at a minute angle and totally reflected to make it difficult for incident light rays and scattered X-rays to enter a detector. Make it smaller.
[0004]
[Problems to be solved by the invention]
However, in the conventional apparatus of FIG. 5, the background can be reduced, but since both the X-ray source 24 and the detector 25 are arranged on the same side with respect to the sample S, both the devices 24 and 25 are brought close to the sample S. Even if it is going to make it, since it is necessary to take each space so that both devices 24 and 25 may not mutually interfere, there was a limit in the distance to which both approach. Accordingly, in the conventional apparatus, the distance between the X-ray source 24 and the detector 25 with respect to the sample S is increased, so that the X-ray intensity of the primary X-ray B1 irradiated on the sample S and the fluorescent X-ray B2 incident on the detector 25 is increased. Therefore, there is a problem that the sensitivity of the detector 25 cannot be increased.
[0005]
Further, in the total reflection type X-ray fluorescence analyzer, the structure becomes complicated and the minute incident angle can be obtained because it is necessary to make the background incident from the X-ray source to the sample at a minute angle. However, it is troublesome to set the position of the X-ray source or the sample.
[0006]
An object of the present invention is to provide a fluorescent X-ray analyzer that solves the above-described problems and is easy to handle and can be highly sensitive.
[0007]
[Means for Solving the Problems]
To achieve the above object, a fluorescent X-ray analyzer according to the configuration of the present invention, the X-ray transparent holding member for holding a sample of the liquid or solid, is placed on one side of the sample the An X-ray source that irradiates the sample with the X-ray for excitation together with the holding material, and a detector that is disposed on the other side of the sample and detects the intensity of fluorescent X-rays generated from the sample, and sandwiches the sample The X-ray source and the detector are arranged obliquely so that the excitation X-ray from the X-ray source does not enter the detector . Here, the X-ray transmissive holding material means a holding material that transmits 90% or more of X-rays.
[0008]
According to the above configuration, the sample is held by the X-ray transmissive holding material, and the X-ray source and the detector are arranged obliquely on the opposite side across the sample. it is possible to irradiate the specimen together with the holding member, and from being disposed and obliquely to each other rather than on the same side from the X-ray source and the detector, it is not necessary to consider the interference of both devices to each other, the both devices Both can be brought close to the sample S. Accordingly, it is possible to easily increase the sensitivity of the detector by increasing the X-ray intensity of the X-ray for excitation from the X-ray source to the sample and the fluorescent X-ray from the sample to the detector.
[0009]
Preferably, the X-ray for excitation from the X-ray source is between the X-ray source on one side of the sample and the holding material and between at least one of the detector on the other side and the holding material. A slit is disposed to prevent the light from entering the light. Therefore, the slit can prevent the excitation X-ray from the X-ray source from directly entering the detector.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a side view of an X-ray fluorescence spectrometer according to the first embodiment of the present invention. This apparatus is an apparatus for X-ray fluorescence analysis of a sample S made of river water, blood, body fluid, semiconductor cleaning liquid or other liquid or a fine solid, and an X-ray transmissive holding material 2 for holding the sample S. An energy dispersive detector 5 such as an X-ray source 4 that irradiates the sample S with the excitation (primary) X-ray B1 and a semiconductor detector that detects the intensity of the fluorescent X-ray B2 generated from the sample S. And an analyzer 6 for analyzing the sample S in response to the output signal.
[0011]
In the present apparatus, an X-ray source 4 is disposed obliquely below the sample S, and a detector 5 is disposed opposite the sample S. 1 may be reversed upside down, the detector 5 may be disposed above the sample S, and the X-ray source 4 may be disposed below.
[0012]
In this apparatus, the primary X-ray B1 from the X-ray source 4 is irradiated upward toward the sample S on the holding material 2, and the holding material 2 is interposed between the X-ray source 4 and the sample S. Although intervening, the holding material 2 is made of a member such as a polymer thin film or paper and transmits most of the X-rays. Therefore, the sample X on the holding material 2 is irradiated with the primary X-rays B1. be able to. The holding member 2 is supported by, for example, a ring-shaped frame 3, and the frame 3 is fixed to the apparatus main body via a support member (not shown) on the side. Further, the X-ray path is evacuated in order to reduce attenuation of X-rays due to air scattering.
[0013]
Further, this apparatus is provided with a slit 7 between the X-ray source 4 on the lower side of the sample S and the holding material 2 and a slit 8 between the detector 6 on the upper side and the holding material 2. 4 prevents the primary X-ray B1 from 4 from entering the detector 6. Therefore, the slits 7 and 8 can prevent the primary X-ray B1 from the X-ray source 4 from directly entering the detector 5.
[0014]
In the present apparatus, the slits 7 and 8 are provided between both of them. However, as long as the primary X-ray B1 can be prevented from entering the detector 6, it may be provided only between either one. Further, the slit 8 can also be used as a slit for setting a glance angle in order to limit the generation region of the fluorescent X-ray B2 incident on the detector 6.
[0015]
When the sample S is analyzed using the fluorescent X-ray analyzer having the above-described configuration, a liquid is particularly preferably used as the sample S. For example, when analyzing river water, the liquid (for example, 10 to 500 μl) is dropped on the holding material 2. This liquid is evaporated to dryness and concentrated. By repeating such liquid dropping and drying, the sample S is accumulated as a fine solid on the holding material 2.
[0016]
Since the X-ray path is evacuated, when the liquid sample S is subjected to fluorescent X-ray analysis as it is, the liquid sample S is placed in a holding material made of, for example, an X-ray transparent and airtight tube. Perform analysis.
[0017]
Excitation (primary) X-rays B1 emitted from the X-ray source 4 arranged below the sample S are applied to the sample S on the holding material 2. The fluorescent X-rays B2 generated from the sample S are detected by the detector 5 arranged facing the upper side of the sample S, and the fluorescent X-ray analysis of the sample S is performed by the analyzer 6 receiving the output signal.
[0018]
In this apparatus, since both the devices 4 and 5 are arranged on the opposite side of the sample such that the X-ray source 4 is below the sample S and the detector 5 is above the sample S, both Without considering the interference between the devices 4 and 5, the sample S and the devices 4 and 5 can be as close together as possible, the distance L1 between the sample S and the X-ray source 4, and the sample S and detection. Both the distances L2 between the vessels 5 can be reduced. Since the X-ray intensity attenuates in proportion to the reciprocal of the square of the distance, that is, 1 / (L1) ² , 1 / (L2) ² , the smaller the distance, the larger the X-ray intensity can be maintained, and 1 / ( Since L1) ² and 1 / (L2) ² are multiplied, the X-ray intensity of the fluorescent X-ray B2 incident on the detector 5 becomes large when both the distances L1 and L2 are small. Thereby, compared with the conventional apparatus of FIG. 5, the detection sensitivity of the detector 5 can be increased 10 times, for example, and the sensitivity of the detector 5 can be increased.
[0019]
As described above, the present apparatus simply arranges the X-ray source 4 and the detector 5 on the opposite side with the sample S held by the X-ray transmissive holding material 2 interposed therebetween, so that the total reflection type fluorescent X-ray analysis is performed. Compared with the apparatus, high sensitivity can be achieved without requiring a troublesome adjustment work. Further, since there is no design restriction that the X-ray source 4 and the detector 5 are always arranged on the same side with respect to the sample S, the degree of freedom in design is improved.
[0020]
FIG. 2 shows a fluorescent X-ray analyzer according to the second embodiment. In this apparatus, the X-ray source 4 is arranged facing the lower side of the sample S, and the detector 5 is arranged obliquely above the upper side of the sample S. Other configurations are the same as those in FIG. Note that the arrangement shown in FIG. 2 may be reversed upside down, and the detector 5 may be arranged on the upper side of the sample S and the X-ray source 4 may be arranged on the lower side.
[0021]
As in the first embodiment, this apparatus can bring both the X-ray source 4 and the detector 5 close to the sample S, and can reduce the distance between the X-ray source 4 and the detector 5 with respect to the sample S. The sensitivity of the device 5 can be increased.
[0022]
FIG. 3 shows a fluorescent X-ray analyzer according to the third embodiment. In this apparatus, the detector 5 is arranged facing the lower side of the sample S, two X-ray sources 4A and 4B are arranged obliquely above the upper side of the sample S and It arrange | positions so that the next X-ray B1 may be irradiated. Other configurations are the same as those in FIG. 3 may be reversed upside down, the detector 5 may be disposed above the sample S, and the X-ray sources 4A and 4B may be disposed below the sample S.
[0023]
In this apparatus, both the X-ray sources 4A and 4B and the detector 5 can be brought close to the sample S, and the distance between the X-ray sources 4A and 4B and the detector 5 with respect to the sample S can be reduced. At the same time, the X-ray intensity of the primary X-ray B1 is doubled because the sample S is irradiated with the two X-ray sources 4A and 4B as compared with the first embodiment. Can be further improved.
[0024]
FIG. 4 shows a fluorescent X-ray analyzer according to the fourth embodiment. This apparatus uses a chromatic dispersion detector 15.
[0025]
This apparatus includes an X-ray transmissive holding material 2 that holds a sample S, an X-ray source 4 that irradiates the sample S with an excitation (primary) X-ray B1, and fluorescent X-rays B2 generated from the sample S. A spectroscope 10 for spectroscopic analysis and a detector 15 for detecting the intensity of fluorescent X-ray B3 from the spectroscope 10 are provided. The spectroscope 10 and the detector 15 are attached to the goniometer 12, and according to the rotation of the spectroscope 10, the detector 15 is rotated so as to detect the fluorescent X-rays B3 from the spectroscope 10.
[0026]
In this apparatus, the X-ray source 4 is disposed below the sample S, and the spectrometer 10 and the detector 15 are disposed above the sample S. 4 may be reversed upside down, the X-ray source 4 may be disposed above the sample S, and the spectrometer 10 and the detector 15 may be disposed below the sample S. Further, a multiple simultaneous analysis type in which a plurality of goniometers are provided around the sample S may be employed.
[0027]
Thus, in this apparatus, the X-ray source 4, the spectrometer 10 and the detector 15 are arranged on the opposite side with respect to the sample S and are not arranged on the same side. 4 and the spectroscope 10 and the detector 15 are not considered, and the spectroscope 10 can be brought as close to the sample S as possible. Therefore, the X-ray source 4 and the spectroscope 10 can be brought close to the sample S, and similarly to the first embodiment, the X-ray intensity incident on the detector 15 can be increased and the sensitivity can be increased. . Further, since there is no design restriction that the X-ray source 4, the spectroscope 10, and the detector 15 are necessarily arranged on the same side with respect to the sample S, the degree of freedom in design is improved.
[0028]
In the above embodiment, X-rays are used as excitation lines, but electron beams may be used as excitation lines.
[0029]
【The invention's effect】
As described above, according to the present invention, the sample is held by the X-ray transmissive holding material, and the X-ray source and the detector are disposed on the opposite sides with the sample interposed therebetween. The sample can be irradiated with X-rays through the holding material, and the X-ray source and the detector are not arranged on the same side, so there is no need to consider interference between the two devices. The sample S can be approached. Therefore, the sensitivity of the detector can be increased by increasing the X-ray intensity of the X-ray for excitation from the X-ray source to the sample and the fluorescent X-ray from the sample to the detector.
[Brief description of the drawings]
FIG. 1 is a side view showing a fluorescent X-ray analysis apparatus according to a first embodiment of the present invention.
FIG. 2 is a side view showing a fluorescent X-ray analyzer according to a second embodiment.
FIG. 3 is a side view showing a fluorescent X-ray analysis apparatus according to a third embodiment.
FIG. 4 is a side view showing a fluorescent X-ray analysis apparatus according to a fourth embodiment.
FIG. 5 is a side view showing a conventional X-ray fluorescence analyzer.
[Explanation of symbols]
2 ... holding material, 4 ... X-ray source, 5 ... detector, 7, 8 ... slit, S ... sample, B1 ... excitation (primary) X-ray, B2 ... fluorescent X-ray.

Claims (2)

An X-ray transmissive holding material for holding a liquid or solid sample;
An X-ray source for irradiating excitation X-ray with the holding member in the sample is disposed on one side of said sample,
A detector that is disposed on the other side of the sample and detects the intensity of fluorescent X-rays generated from the sample ;
An X-ray fluorescence analyzer in which the X-ray source and the detector are arranged obliquely with respect to each other so that excitation X-rays from the X-ray source do not enter the detector with the sample interposed therebetween . In claim 1,
X-rays for excitation from the X-ray source enter the detector between at least one of the X-ray source on one side of the sample and the holding material and between the detector on the other side and the holding material. X-ray fluorescence analyzer in which a slit for preventing the above is arranged.

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