JP2003254919A - Fluorescent x-ray analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for highly accurately analyzing by solving the problem of attenuation or fluctuation of a fluorescence X-ray caused by absorption in a space formed between a sample and a bulkhead film, concerning a fluorescent X-ray analyzer for performing analysis in a helium atmosphere. <P>SOLUTION: This analyzer is equipped with a passage 18 for introducing helium into the space formed between the sample 1 and the bulkhead film 9. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an X-ray fluorescence analyzer for analysis in a helium atmosphere.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, there is a fluorescent X-ray analyzer for performing analysis in a helium atmosphere (the X-ray optical path is in a helium atmosphere). This apparatus is a bottom irradiation type in which primary X-rays 6 are irradiated from below the sample 1, and an X-ray source 7 is housed below a sample chamber 3 in which the sample 1 is replaceably housed in an air atmosphere. The irradiation chamber 8 and a spectroscopic chamber 14 that communicates with the irradiation chamber 8 and accommodates the spectroscopic element 11 and the detector 13 are provided. Since the irradiation chamber 8 and the spectroscopic chamber 14 are replaced with helium, the fluorescent X-rays 1
The absorption of 0 and 12 is small, and it is easy to detect even the fluorescent X-rays 10 of light elements and the weak fluorescent X-rays 10 that are significantly attenuated in the air. Here, the partition wall film 9 that allows the X-rays 6 and 10 to pass therethrough.
However, the sample chamber 3 in the atmosphere and the irradiation chamber 8 in the helium atmosphere
It is arranged so as to separate the and.

As analyzed in a helium atmosphere,
There is a liquid sample 1a. In that case, the liquid sample 1a is
It is placed in a liquid sample holder 2 having an irradiation window 2a that allows X-rays 6 and 10 to pass therethrough, and is treated as a sample 1 by the whole 1a and 2 and mounted on a partition film 9 in a sample chamber 3 in an air atmosphere. Placed. The exuded liquid sample 1a may be attached to the outside of the irradiation window 2a of the liquid sample holder 2, and the irradiation window 2a and the partition film 9 are prevented from adhering to the partition film 9 and contaminating it. A space of about 1 mm, that is, a space 18 having a thickness of about 1 mm is provided between the sample 1, that is, between the sample 1 and the partition film 9.

[0004]

Since this space 18 is a part of the sample chamber 3 in the atmosphere, it is filled with air and absorbs and attenuates the fluorescent X-rays 10 generated from the sample 1. . Moreover, since the thin partition wall film 9 is likely to be wrinkled or bent, and the thickness of the space 18 changes accordingly, the degree of attenuation of the fluorescent X-ray 10 also changes. Therefore, the intensity of the fluorescent X-ray 10 is reduced and unstable.
Therefore, high precision analysis cannot be performed.

The present invention has been made in view of the above-mentioned conventional problems, and in a fluorescent X-ray analyzer for analyzing in a helium atmosphere, fluorescent X-rays due to absorption in a space formed between a sample and a partition film. It is an object of the present invention to solve the problems of attenuation and fluctuation of and to provide the one capable of highly accurate analysis.

[0006]

In order to achieve the above object, the present invention is as follows. First, a sample chamber in which a sample is replaceably housed in an air atmosphere, and an X-ray source for irradiating the sample with primary X-rays. An irradiation chamber in which is stored, a partition wall film which is arranged so as to partition the sample chamber and the irradiation chamber and which allows passage of X-rays, and a detection unit which disperses and detects fluorescent X-rays generated from the sample, A fluorescence X-ray analysis apparatus comprising a spectroscopic chamber communicating with the irradiation chamber, and the irradiation chamber and the spectroscopic chamber being replaced with helium. A flow path for introducing helium is provided in a space formed between the sample and the partition film.

According to the X-ray fluorescence analyzer of the present invention, the space formed between the sample and the partition film is also replaced with helium, which absorbs less X-ray fluorescence, so that the X-ray fluorescence is attenuated there. The problem of fluctuations is eliminated, and highly accurate analysis is possible. Here, it is preferable that the flow path introduces helium introduced into the irradiation chamber and the spectroscopic chamber for helium replacement into the space. Further, the flow path includes a tube that is curved or bent in a holder that holds and supports the peripheral portion of the partition wall film in the thickness direction, or includes a tube that communicates with the space and extends to the irradiation chamber. Therefore, it is more preferable to prevent air from flowing back from the space to the irradiation chamber and the spectroscopic chamber. Furthermore, the flow path may be a hole provided in the partition wall film.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The X-ray fluorescence analyzer according to the first embodiment of the present invention will be described below in terms of its configuration. This device, like the device described in the prior art, is shown in FIG.
As shown in FIG. 1, the sample chamber 3, the irradiation chamber 8, and the partition wall film 9 are of a bottom irradiation type in which the primary X-ray 6 is irradiated from below the sample 1.
Also, the fluorescent X-ray analyzer is provided with the spectroscopic chamber 14, and the irradiation chamber 8 and the spectroscopic chamber 14 are replaced with helium. Sample chamber 3
Is composed of a space surrounded by a main body case 4 and a lid body 5 which is attached to the upper portion of the main body case 4 via a seal member so as to be openable and closable, and the sample 1 is exchangeably accommodated in an air atmosphere. The irradiation chamber 8 is an X-ray tube or the like for irradiating the sample 1 with the primary X-rays 6.
The radiation source 7 is stored. The partition wall film 9 includes a sample chamber 3 and an irradiation chamber 8.
The X-rays 6 and 10 are arranged so as to partition and. The spectroscopic chamber 14 is in communication with the irradiation chamber 8 and includes a detection device 11 including a spectroscopic element 11 that disperses the fluorescent X-rays 10 generated from the sample 1 and a detector 13 that detects the dispersed fluorescent X-rays 12. , 13 are stored. The spectroscopic element 11 and the detector 13 are rotated with a constant angular relationship by an interlocking device such as a goniometer (not shown).

Here, as described above, the analysis target is, for example, the liquid sample 1a, and the liquid sample 1a has X at the bottom.
It is placed in a cylindrical liquid sample holder 2 having an irradiation window 2a that allows the lines 6 and 10 to pass therethrough, and the whole 1a, 2 is treated as a sample 1 and mounted on a partition film 9 in a sample chamber 3 in the air atmosphere. Placed. A gap of about 1 mm, that is, a space 18 having a thickness of about 1 mm is provided between the irradiation window 2a and the partition film 9, that is, between the sample 1 and the partition film 9.

In this apparatus, the irradiation chamber 8 and the spectroscopic chamber 14 are
In order to replace helium with helium, the following pipes, valves and pumps are provided. Helium flow pipe 1
5A is an irradiation chamber 8 via a helium flow valve 16A.
And helium is introduced into the spectroscopic chamber 14 from a helium tank (not shown). The vacuum pipe 15B evacuates the irradiation chamber 8 and the spectroscopic chamber 14 by the vacuum pump 17 via the vacuum valve 16B. The spectroscopic chamber leak pipe 15C is connected to the irradiation chamber 8 and the spectroscopic chamber 1 via the spectroscopic chamber leak valve 16C.
Open 4 to the atmosphere. Sample chamber leak piping 15D
Opens the sample chamber 3 to the atmosphere via the sample chamber leak valve 16D. The bypass pipe 15E connects the spectroscopic chamber leak pipe 15C and the sample chamber leak pipe 15D via the bypass valve 16E.

FIG. 9 is an enlarged view of the vicinity of the space 18 of FIG.
As shown in FIG. 1 including the I-I cross section of FIGS. 2 to 4 described later, the holder 20 includes a holder upper portion 23 and a holder lower portion 2.
1, including the seal member 22 and the O-ring 24, the peripheral portion of the partition wall film 9 is sandwiched and supported in the thickness direction (vertical direction in FIG. 1). In FIG. 1, for easy understanding,
The line that appears deeper than the page is not shown (this point is
The same applies to FIGS. 5 to 7 described later).

First, as shown in a top view of FIG. 2 (a) and a bottom view of FIG. 2 (b), the holder lower part 21 is a ring-shaped metal plate and is concentric with the holder lower part 21 on the lower surface. A groove 21b for fitting the O-ring 24 (FIG. 1) is formed, and a through hole 21 having a diameter of about 1 mm is formed inside the groove 21b.
a is provided. As shown in FIG. 1, the O-ring 24 is
The lower part 21 of the holder and the case body 4 are sealed. On the upper surface of the holder lower portion 21 of FIG. 2A, a pair of convex portions 21c and 21d are formed concentrically so that a concave portion 21e is relatively formed between them.
The through hole 21a is located at e. A seal member 22 which is a ring-shaped rubber plate is fitted in the recess 21e as shown in FIG. 1. The seal member 22 is also provided with a through hole 22a and communicates with the through hole 21a of the lower holder portion 21. The seal member 22 seals between the holder lower portion 21 and the partition wall film 9.

The partition film 9 has a top view as shown in FIG.
As shown in the bottom view of FIG. 3B, a circular film made of polyimide, polyester, or the like having a thickness of about several μm is attached to a support plate 19 which is a ring-shaped metal plate and handled. The partition film 9 and the support plate 19 communicate with the through hole 9
a and 19a are provided respectively.

The holder upper portion 23 is shown in a top view in FIG.
As shown in the bottom view of FIG. 4B, a ring-shaped metal plate is provided with a recess 23a in the inner peripheral portion of the lower surface.
As shown in FIG. 1, the support plate 19, the outer peripheral portion of the partition wall film 9, the convex portions 21c and 21d of the holder lower portion 21 and the seal member 22 are fitted into the concave portion 23a so that the holder upper portion 23 and the holder lower portion 21 have the outer periphery. The whole parts 20, 19, and 9 which are connected by screwing or the like in the part and integrated into one form a partition membrane cartridge. The central portion of the recess 23a on the lower surface of the holder upper portion 23 in FIG. 4B is further recessed to form a groove 23b which is less than one turn in the circumferential direction. One end 23b of the groove
a communicates with the through hole 19a (FIG. 1) of the support plate 19, and the other end 23bb extends to the inner circumference of the holder upper portion 23 in the radial direction. On the other hand, a groove 23c that extends in the radial direction and connects the inner circumference and the outer circumference is formed on the upper surface.

With the structure of the holder 20, the partition wall film 9 and the support plate 19 as described above, the through hole 21a of the lower holder portion 21, the through hole 22a of the seal member 22 and the partition wall film 9 are viewed from below in FIG. Through hole 9a, through hole 1 of support plate 19
9a and one end portion 2 on the lower surface of the holder upper portion 23
One channel is formed by communicating the groove 23b extending from 3ba to the other end portion 23bb. This channel is
Helium introduced into the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8) for helium substitution is introduced into the space 18 formed between the sample 1 and the partition film 9. Further, this flow path is formed in the holder 20, the partition film 9 and the support plate 19, but is formed by bending and bending as a groove 23b on the lower surface of the holder upper portion 23 (FIG. 4).
(B)) The entire length of the flow path is secured to prevent air from flowing back from the space 18 to the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8).

In order to smoothly replace helium in the space 18, the holder upper part 23 serves as an outlet for air from the space 18.
The groove 23c (FIG. 4 (a)) on the upper surface of the device functions. Instead of forming such a groove, for example, a tape is attached to a part of the upper surface of the holder upper portion 23, so that the liquid sample holder 2
A space may be provided between the space and the bottom surface to allow the air in the space 18 to escape from the space.

Next, the operation of this device will be described.
First, in FIG. 8, before putting the sample 1 into the sample chamber 3,
Helium flow valve 16A, spectroscopic chamber leak valve 16
C and the sample chamber leak valve 16D are closed, the vacuum valve 16B and the bypass valve 16E are opened, and the irradiation chamber 8 and the spectroscopic chamber 14 and the sample chamber 3 are evacuated by the vacuum pump 17. When the predetermined degree of vacuum is reached, the vacuum valve 16B is closed, the vacuum pump 17 is stopped, the helium flow valve 16A is opened, and helium is introduced into the irradiation chamber 8, the spectroscopic chamber 14, and the sample chamber 3. And
The bypass valve 16E is closed, and the spectroscopic chamber leak valve 16 is closed.
Helium is flown into the irradiation chamber 8 and the spectroscopic chamber 14 at a low flow rate by opening C. This completes the helium replacement of the irradiation chamber 8 and the spectroscopic chamber 14. Note that the sample chamber 3 is also evacuated and helium is introduced in order to prevent the partition film 9 from being damaged due to the pressure difference between the sample chamber 3 and the irradiation chamber 8 and the spectroscopic chamber 14. is there.

On the other hand, the sample chamber leak valve 16D is opened,
When the lid 5 is opened, the sample 1 can be replaced in the sample chamber 3 in the air atmosphere.
On the sample holder upper part 23 (FIG. 1), and the lid 5 is closed. After that, the sample chamber 3 is maintained in the atmospheric atmosphere, and the irradiation chamber 8 and the spectroscopic chamber 14 are maintained in the helium atmosphere having a slightly higher pressure than that, so that the sample 1 can be exchanged only by opening and closing the lid 5. Is.

Now, as shown in FIG. 1, by mounting the sample 1 on the sample holder upper portion 23, as described in the prior art, between the irradiation window 2a and the partition film 9, A disk-shaped space 18 having a thickness of about 1 mm is formed. conventionally,
This space 18 was still filled with air,
In the apparatus of the embodiment, the flow paths 21a, 22a, 9a,
Since the space 18 is also replaced by helium, which absorbs less fluorescent X-rays by 19a and 23b, the problem of attenuation and fluctuation of fluorescent X-rays there is solved, and highly accurate analysis can be performed.
Moreover, as the helium introduced into the space 18, the irradiation chamber 8
And helium is saved because it is reused for the helium introduced into the spectroscopic chamber 14 (FIG. 8). In addition, since the flow path is formed by bending and bending as the groove 23b on the lower surface of the holder upper portion 23 (FIG. 4B), the entire length of the flow path is ensured, and the space 18 to the irradiation chamber 8 is secured. And, backflow of air into the spectroscopic chamber 14 (FIG. 8) is prevented. Therefore, the helium atmosphere in the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8) is maintained at a higher level for a longer time,
More accurate analysis can be performed for a longer time.

Next, an X-ray fluorescence analyzer according to the second embodiment of the present invention will be described. The configuration of the device other than the holder 30 is the same as that of the device of the first embodiment, and therefore the description thereof is omitted. As for the holder 30, as shown in FIG. 5, in the recess 33a on the lower surface of the holder upper portion 33, a groove 23b elongated in the circumferential direction as in the first embodiment (FIG. 4B).
Instead, a short groove 33b communicating with the through hole 19a of the support plate 19 and extending in the radial direction to the inner circumference of the holder upper portion 33 as it is.
Are formed. On the other hand, the through hole 32 of the holder lower portion 31
A tube 35 having an inner diameter of 0.2 mm and a length of about 150 mm is attached to a, and hangs down inside the irradiation chamber 8.

That is, in the apparatus of the second embodiment, when viewed from below in FIG. 5, the pipe 35 and the through hole 3 of the lower holder portion 21.
1a, the through hole 32a of the sealing member 32, the through hole 9a of the partition wall film 9, the through hole 19a of the support plate 19, and the groove 33b on the lower surface of the holder upper part 33 communicate with each other to form a flow path. This flow path is provided in the irradiation chamber 8 and the spectroscopic chamber 14.
Helium introduced for helium substitution in FIG. 8 is introduced into the space 18 formed between the sample 1 and the partition film 9. Further, this flow path includes a long and narrow tube 35 which communicates with the space 18 and extends to the irradiation chamber 8, so that the entire length of the flow path is ensured and the space 18 is irradiated with the irradiation chamber 8.
And preventing backflow of air into the spectroscopic chamber 14 (FIG. 8). Therefore, even with the device of the second embodiment, the first
The same effects as the device of the embodiment are obtained.

Next, an X-ray fluorescence analyzer according to the third embodiment of the present invention will be described. The configuration of this device other than the holder 40 is the same as that of the devices of the first and second embodiments, and therefore the description thereof is omitted. As for the holder 40, as shown in FIG. 6, the through hole 21 a of the lower holder 21 and the through hole 2 of the seal member 22 in which the flow path is formed in the first embodiment of FIG.
2a, through hole 9a of partition wall film 9, through hole 19 of support plate 19
a, and there is no groove 23b on the lower surface of the holder upper part 23,
Instead, the portion not supported by the holder 40 (support plate 19
(The part which does not abut) has a diameter of 0.1
A hole 9a of about mm forms a flow path. This channel 9
Also in a, helium introduced into the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8) for helium substitution is introduced into the space 18 formed between the sample 1 and the partition film 9. However, since the flow path 9a is extremely short, it is not possible to sufficiently prevent the air from flowing back from the space 18 to the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8). Therefore, according to the device of the third embodiment, there is an effect similar to those of the devices of the first and second embodiments with a simple configuration.

Next, an X-ray fluorescence analyzer according to the fourth embodiment of the present invention will be described. The configuration of this device other than the holder 50 is the same as that of the devices of the first, second, and third embodiments, and a description thereof will be omitted. As for the holder 50, as shown in FIG. 7, the through hole 21a of the holder lower portion 21, the through hole 22a of the seal member 22, the through hole 9a of the partition wall film 9 in which the flow path is formed in the first embodiment of FIG. Through hole 1 of support plate 19
9a and the groove 23b on the lower surface of the holder upper part 23 are not provided, but instead, the tube 55 is embedded in the radial groove 53b formed on the upper surface of the holder upper part 53, and the tube 55 is connected to the spectroscopic chamber leak valve 16C. It is in communication.

That is, in the apparatus of the fourth embodiment, the flow path is formed by the vacuum pipe 15B of FIG. 8, the spectroscopic chamber leak pipe 15C, the spectroscopic chamber leak valve 16C and the pipe 55 of FIG. 7 communicating with each other. . This channel also introduces the helium introduced into the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8) for replacing helium into the space 18 formed between the sample 1 and the partition film 9. In addition, this flow path is
By being formed longer than the flow path of the second embodiment, backflow of air from the space 18 to the irradiation chamber 8 and the spectroscopic chamber 14 (FIG. 8) is prevented. Therefore, the device of the fourth embodiment also has the same effects as the devices of the first and second embodiments.

In the flow path of the apparatus of the above embodiment, the helium introduced for helium substitution into the irradiation chamber 8 and the spectroscopic chamber 14 of FIG. 8 is a space formed between the sample 1 and the partition film 9. Although it was introduced into 18, a second helium flow pipe is provided as a flow path separately from the helium flow pipe 15A,
Helium from the pipe may be directly introduced into the space 18.

Further, in the apparatus of the above-mentioned embodiment, the evacuation was performed in order to quickly complete the helium replacement of the irradiation chamber 8 and the spectroscopic chamber 14. However, a large amount of helium was caused to flow at a high flow rate without evacuation. The helium may be replaced by expelling the air and then flowing it at a low flow rate. In this case, it takes time to complete the helium replacement (air ejection reaches the limit and X-ray absorption is stabilized), but the irradiation chamber 8 and the spectroscopic chamber 14 are not evacuated, and Therefore, the vacuuming of the sample chamber 3 and the replacement of helium are unnecessary, and the procedure is simple.

In the above embodiment, the detecting means 1
The wavelength dispersive X-ray fluorescence analyzers 1 and 13 are composed of the spectroscopic element 11 and the detector 13, but the present invention is
The same can be applied to an energy dispersive X-ray fluorescence analyzer in which the detection means is a detector such as SSD and does not include a spectroscopic element.

[0028]

As described in detail above, according to the X-ray fluorescence analyzer of the present invention, the space formed between the sample and the partition film is also replaced with helium, which absorbs less X-ray fluorescence. Therefore, the problems of the attenuation and fluctuation of the fluorescent X-rays are solved, and highly accurate analysis can be performed.

[Brief description of drawings]

FIG. 1 is an enlarged view of a vicinity of a space formed between a sample and a partition film in an X-ray fluorescence analyzer according to a first embodiment of the present invention, including a cross section taken along line I-I of FIGS. 2 to 4. It is a figure.

FIG. 2A is a top view of a lower portion of a holder of the device,
(B) is a bottom view.

FIG. 3A is a top view of a partition film and a support plate of the same device, and FIG. 3B is a bottom view thereof.

FIG. 4 (a) is a top view of a holder upper part of the device,
(B) is a bottom view.

FIG. 5 is an enlarged view of the vicinity of a space formed between a sample and a partition film in the fluorescent X-ray analysis apparatus according to the second embodiment of the present invention.

FIG. 6 is an enlarged view of a vicinity of a space formed between a sample and a partition film in a fluorescent X-ray analysis apparatus according to a third embodiment of the present invention.

FIG. 7 is an enlarged view of the vicinity of a space formed between a sample and a partition film in an X-ray fluorescence analyzer according to a fourth embodiment of the present invention.

FIG. 8 is a schematic diagram showing a fluorescent X-ray analyzer for performing analysis in a helium atmosphere.

[Explanation of symbols]

1 ... Sample, 3 ... Sample chamber, 6 ... Primary X-ray, 7 ... X-ray source, 8
... irradiation chamber, 9 ... partition film, 9a ... holes provided in the partition film,
10 ... Fluorescent X-ray generated from sample, 11, 13 ... Detecting means, 12 ... Spectral fluorescent X-ray, 14 ... Spectroscopic chamber, 18 ...
Space formed between the sample and the partition film, 20, 30, 4
0, 50 ... Holder, 35 ... Tubes communicating with the space and extending to the irradiation chamber.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsumi Kimoto             14-8 Akaoji-cho, Takatsuki-shi, Osaka Rigaku Denki             Industry Co., Ltd. (72) Inventor Yukio Sako             14-8 Akaoji-cho, Takatsuki-shi, Osaka Rigaku Denki             Industry Co., Ltd. F-term (reference) 2G001 AA01 BA04 CA01 EA01 KA01                       PA07 QA01

Claims (5)

[Claims] 1. A sample chamber in which the sample is exchangeably housed in an air atmosphere, an irradiation chamber in which an X-ray source for irradiating the sample with primary X-rays is housed, and the sample chamber and the irradiation chamber are partitioned from each other. An irradiation chamber and a spectroscopic chamber, each of which is provided with a partition wall film that transmits X-rays, and a spectroscopic chamber that accommodates a detection unit that spectroscopically detects fluorescent X-rays generated from a sample and that communicates with the irradiation chamber. In the fluorescent X-ray analysis apparatus in which helium is replaced with helium, a flow path for introducing helium is provided in a space formed between the sample and the partition film. 2. The fluorescent X according to claim 1, wherein the flow path introduces helium introduced into the irradiation chamber and the spectroscopic chamber for helium replacement into the space.
Line analyzer. 3. The holder according to claim 2, wherein the flow path is formed by bending or bending a holder that holds and supports the peripheral portion of the partition wall film in the thickness direction thereof.
An X-ray fluorescence analyzer for preventing air from flowing back from the space to the irradiation chamber and the spectroscopic chamber. 4. The flow path according to claim 2, wherein the flow path includes a pipe that communicates with the space and extends to the irradiation chamber, and prevents air from flowing back from the space to the irradiation chamber and the spectroscopic chamber. X-ray fluorescence analyzer. 5. The X-ray fluorescence analyzer according to claim 2, wherein the flow path is a hole provided in the partition film.