JP3422980B2 - X-ray fluorescence analyzer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a fluorescent X-ray analyzer for measuring fluorescent X-rays from a sample and analyzing the sample. The present invention relates to an X-ray fluorescence analyzer suitable for reliable protection.

[0002]

2. Description of the Related Art Conventionally, X is applied to a sample placed in a vacuum analysis chamber.
An X-ray fluorescence analyzer for measuring a fluorescent X-ray generated from a sample by irradiating the sample and analyzing the sample has already been widely used in the analysis of various substances in various fields. In such an X-ray fluorescence analyzer, in order to maintain a predetermined vacuum state in the sample chamber and the spectroscopic chamber in the apparatus during the analysis work, the apparatus is usually operated while driving a vacuum means such as a vacuum pump. . In addition, many of such fluorescent X-ray analyzers are provided with a peripheral device using a so-called personal computer or the like in order to process and display / output the measurement result, or to set a sample analysis procedure or the like. ing.

By the way, in such a fluorescent X-ray analyzer,
A detector for measuring fluorescent X-rays from the X-ray-irradiated sample is provided in the spectroscopic chamber, but in order to improve the analytical ability of the device, fluorescent X-rays from the sample to be analyzed may be added as necessary. It is required that X-rays can be counted and detected in a wide wavelength range (spectrum). For that purpose, a plurality of various detectors are provided in the device, and these are appropriately selected according to the wavelength. Used. The fluorescent X-ray detector is generally, for example, a scintillation counter composed of a phosphor and a photomultiplier tube, and a detection gas (air or the like) is contained or flown therein. The proportional coefficient tube used is used. Further, these detectors are generally provided with a window portion made of a transparent member such as glass in order to introduce the X-ray to be detected therein.

[0004]

Therefore, the following problems have been pointed out in the conventional X-ray fluorescence analyzer. That is, when using the above-mentioned plurality of types of detectors in the apparatus, particularly when the detection gas is contained in the detector, or when a proportional coefficient tube or the like used while flowing is used, If the window or the gas (air) supply tube is damaged for some reason, the gas or air inside the tube will flow out into the spectroscopic chamber, and the apparatus will fall into a state of poor vacuum despite the operation of the vacuum pump. Also,
If this state is left as it is and analysis operation is continued,
Detector (especially gas flow type proportional coefficient tube (F-PC))
Then, the first-stage FET of the detection circuit to which a high voltage of about 1000 V is applied is damaged, and the F-PC itself is burnt black and damaged. On the other hand, on the vacuum pump side, the vacuum pump itself generates heat. damage it and that Do not be. With this,
A relatively expensive X-ray fluorescence analyzer cannot be protected safely and surely.

Therefore, in the present invention, the above-mentioned problems in the prior art, in particular, fluorescence that enables the analyzer to stop the analysis operation safely and reliably without damaging the analyzer itself due to defective vacuum in the device. An object is to provide an X-ray analyzer.

[0006]

According to the present invention, in order to achieve the above-mentioned object, first, a sample is placed in a sample chamber kept at a predetermined vacuum degree by a vacuum degree control means and an X-ray tube is placed. From the sample, and the fluorescent X-rays generated from the sample are dispersed by the spectroscopic means provided in the spectroscopic chamber kept at a predetermined vacuum degree by the vacuum degree control means. An X-ray fluorescence analyzer for measuring the intensity by an X-ray detector to analyze the sample, which comprises means for detecting the degree of vacuum in a main chamber including at least the spectroscopic chamber: At least the inside of the line detector is filled with gas, and the fluorescence X
It includes a detector having a window for guiding the wire to the inside, and detects an abnormality in the degree of vacuum in the main chamber based on the degree of vacuum from the degree-of-vacuum detection means provided in the main chamber. There is provided a fluorescent X-ray analysis apparatus which, when detecting the abnormality, stops the operation of the vacuum degree control means and stops application of a high voltage to the X-ray detector.

Further, according to the X-ray fluorescence analyzer of the present invention, the abnormality of the vacuum degree in the main chamber is compared with the predetermined value by the vacuum degree from the vacuum degree detecting means provided in the main chamber. Or by calculating the vacuum degree change rate based on the vacuum degree from the vacuum degree detecting means provided in the main chamber, and comparing the calculated vacuum degree change rate with a predetermined vacuum degree change rate. To detect.

Further, according to the X-ray fluorescence analyzer of the present invention, when an abnormality in the degree of vacuum in the main chamber is detected, the abnormality in the degree of vacuum in the spectroscopic chamber is displayed, or the fluorescence is detected. It can be displayed on the display means of a peripheral device which is configured separately from the X-ray analysis device.

According to the fluorescent X-ray analysis apparatus of the present invention, a predetermined value to be compared for detecting an abnormality in the degree of vacuum in the main chamber, or an abnormality in the degree of vacuum in the main chamber is detected. The predetermined vacuum degree change rate for detection is variable.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First,
FIG. 2 shows an external configuration of a fluorescent X-ray analyzer according to an embodiment of the present invention.

As is clear from FIG. 2, a fluorescent X-ray analysis apparatus, which is a type of analysis apparatus, has an apparatus main body 1 for performing analysis work and an operation connected to the apparatus main body via a communication line. The personal computer device 2 serves as a device (peripheral device). Although not shown here, the apparatus main body 1 has a sample chamber in which a sample to be measured is placed, an X-ray tube for generating X-rays to irradiate the placed sample, in a vacuum chamber inside thereof. The fluorescent X-rays generated from the sample are dispersed, for example, a spectroscopic means composed of a spectroscopic crystal plate, and the X-rays spectroscopically separated by the spectroscopic means are detected.
For example, a scintillation counter and a detector including a gas flow type proportional coefficient tube (F-PC) are provided. Further, although not shown here, needless to say, a vacuum pump and a vacuum exhaust system for maintaining a vacuum state in the inside of the apparatus main body 1 as well as various sensors and valves are provided.

A sample exchange section (machine) 2 is provided on the upper part of the apparatus main body 1 in order to enable automation of analysis by the apparatus.
00 is provided. Inside the sample exchange unit 200, as shown in the drawing, a sample table 201 and a transport mechanism 202 such as a robot arm for sequentially transporting and discharging a sample holder arranged on the table into the sample chamber of the apparatus. Is provided. In addition, on the upper surface of the sample table 201, a sample holder having a substantially cylindrical outer shape made of metal is mounted with a sample to be analyzed on its upper end surface.
Plural are arranged side by side. In addition, the sample introduction section (front opening of the exchange), which is an opening between the inside and the outside of the sample exchange section 200, is made of, for example, a transparent glass plate or the like.
A so-called cover 203 is attached so as to be openable and closable.

The analysis result of the analysis work by the main body 1 of the apparatus is transferred to the main body 21 of the personal computer apparatus 2 and, if necessary, a predetermined analysis operation is performed, and then displayed on the display apparatus 22. Alternatively, it is output by the output means such as the printer 23.

FIG. 3 shows the internal circuit configuration of the fluorescent X-ray analysis apparatus according to the above-described embodiment, particularly the apparatus main body 1. That is, on the apparatus main body 1 side of the X-ray fluorescence analysis apparatus, a gas flow type proportional coefficient that constitutes a part of the detection unit together with a vacuum pump 300 for bringing a sample chamber and a spectroscopic chamber in the apparatus into a vacuum state. A pipe (F-PC) 400 is provided. The F-PC 400 is used while being filled with gas (including air) or flowing. In addition, the main chamber (that is,
A vacuum degree detection sensor 30 configured by, for example, a Pirani gauge for detecting a vacuum state of a vacuum chamber including a spectroscopic chamber.
1 is provided. Furthermore, although not shown, X for analysis
X-ray tube part that generates X-rays and its power source, vacuum exhaust system consisting of valves for securing vacuum inside the device, sample transfer mechanism for transferring the sample in the device, from the sample A spectroscope for separating the generated fluorescent X-rays, another X-ray detector different from the above for detecting the intensity of the fluorescent X-rays dispersed by the spectroscope, and the like are provided. A control unit 100 including a control computer is provided in the device body 1 for driving the various devices by the control signals and performing necessary measurement operations by the sensors and the like. .

The control unit 100 is an MPU (micro processing unit) that executes a predetermined control calculation.
And various memories, and outputs drive / control signals to various devices of the device main body 1 including the vacuum pump 300 via the I / O device (input / output unit) 101, and the various types thereof. The detection output from the sensor is input. Further, the control unit 100 is connected to the personal computer device 2 via a communication line 3 such as a LAN (local area network), so that the data and the data are mutually exchanged. It is configured to be able to communicate information including commands.

As is clear from the figure, the personal computer device 2 is the printer 2 described above.
In addition to 3, etc., a main body 21, a display device 22, and a keyboard 24 and a mouse 25 which are input devices are provided.

FIG. 4 shows a part of the internal structure of the X-ray fluorescence analyzer main body 1. In the figure, the sample inlet door 103 can be moved, for example, in the front-back direction on the paper surface of the figure, and the sample holder SH that has been transported by a transport mechanism (not shown) is shown in FIG. Then, it is put into the sample chamber 13 through the preliminary exhaust chamber 11. Then, the sample holder moving mechanism 12 provided inside the apparatus body 1 conveys the sample chamber 13 in a vacuum state to a predetermined position (for example, a boundary position with the tube chamber 14) and fixes it at that position. (Indicated by a broken line in the figure). In this state, as shown in the figure, the measurement surface (lower surface) of the sample holder SH is irradiated with X-rays from the X-ray tube 141 arranged in the tube chamber 14 described above. As a result, the fluorescent X-rays generated from the sample on the measurement surface are guided through the slit 15 into the spectroscopic chamber 16 which is also held in a vacuum state, and after being spectroscopically separated by the spectroscopic crystal plate 17 or other spectroscopic means, The intensity is measured by the scintillation counter 18 which is an X-ray detector and the F-PC400 which is a proportional coefficient tube.
The detection is similar to that of the conventional X-ray fluorescence analyzer. In this figure, reference numeral 301 denotes the above-mentioned vacuum degree detection sensor, which detects the degree of vacuum in the main chamber composed of the sample chamber 13, the tube chamber 14 and the spectroscopic chamber 16, for example. .

An example of a gas flow type proportional coefficient tube (F-PC) 400 constituting a part of the above X-ray detector is shown in the attached FIGS. 5 and 6. As shown in the figure, for example, a slit-shaped X-ray entrance window portion 420 is provided on one side surface of a highly-sealed cylindrical member (housing) 410 made of a metal member, and the window portion 420 is covered. A so-called transparent window member 430 is fixed and configured. In addition, inside the X-ray detector 400, as shown in FIG.
e, gas G for X-ray detection such as air is enclosed, and gas (air) supply tubes 460, 460 for guiding gas or air into the detector in a part thereof (see FIG. 5)
Is provided in the center of the
A core wire 440 made of Pt wire of about μm is stretched.

Further, in FIG. 6, the electrode 450 is
And +1200 to the core wire 440 through the resistor R.
~ 1500V high voltage (HV) is supplied, while
X-ray detected by the core wire 440 (fluorescent X-ray KX)
Is taken out as an electric signal via a capacitor C, its amplitude is further amplified by an amplifier A in the subsequent stage, its intensity is measured as a pulse signal by a pulse height analyzer (PHA), and if necessary, other devices Will be transferred to the part. An FET is usually provided in the first stage of this amplifier A.
Is likely to be damaged due to continued vacuum failure due to gas (air) leakage, or to be damaged by burning itself in black.

Further, according to the present invention, the fluorescent X-ray analysis apparatus described above further executes a vacuum degree abnormality detection / protection operation described below. The operation is executed by the control unit 100 provided in the apparatus body 1 at regular intervals according to a program stored in the storage device in advance.

As shown in FIG. 1 attached, first, processing is started at a constant cycle, and it is judged from the atmosphere of the main chamber whether the main chamber is in a vacuum or in an atmosphere or gas atmosphere. (Step S11). Note that, as described above, the main chamber has been described as including the sample chamber 13, the tube chamber 14, and the spectroscopic chamber 16 in the present example, however, the main chamber is not limited to this. Any place that can achieve the object and effect of the present invention may be used, and instead of the vacuum degree of the spectroscopic chamber 16 described above, for example, the vacuum degree in the sample chamber 13 or the vacuum degree in the tube chamber 14 is detected. You may. And
Specifically, the atmosphere state of the main chamber (for example, a flag indicating that the main chamber is in the atmosphere, gas, or vacuum) is stored in advance by the atmosphere control of the main chamber. Then, this remembered atmosphere of the main room (ie, atmosphere, gas,
When it is determined to be "atmosphere, gas" based on (vacuum), the process moves to "other processes", but since the content thereof is not related to the present invention, detailed description thereof will be omitted here.

On the other hand, if the result of determination is "vacuum", then the flow shifts to step S12. That is,
In step S12, it is determined whether or not the degree of vacuum in the main chamber is being controlled (moving to a predetermined degree of vacuum). this is,
The degree of vacuum in the main chamber including the spectroscopic chamber normally fluctuates when the apparatus is in transition to a vacuum state. In such a case, the gas flow type proportional coefficient tube (FP) as described above is used.
Since gas (air) leakage from C) does not cause a problem, this is a process for eliminating the case where the main chamber including this spectroscopic chamber is in transition to a vacuum state. If the determination is "yes" (= main room control is in progress), it is not related to the present invention as in the above case, and the process moves to "other processing".

If "NO" in the step S12, that is, if the degree of vacuum in the main chamber is not under control (moving to a vacuum state), then in step S13, the degree of vacuum in the main chamber is "normal". Or “abnormal”. That is, in step S11, it is determined to be "vacuum", and the subsequent step S12.
If it is determined that the main room is not under control,
The apparatus main body 1 should already be in a vacuum state and ready for an analysis operation. In that case, the degree of vacuum in the main chamber including the spectroscopic chamber 13 must be stable at a predetermined value and within a predetermined range.

Therefore, according to the present invention, the gas flow type proportional coefficient is confirmed by confirming the degree of vacuum, which originally should be stable at a predetermined degree of vacuum in the main chamber. It is intended to detect the occurrence of gas (air) leakage from the window of the pipe (F-PC) or damage to the supply tube. More specifically, in the present embodiment, the detected main chamber vacuum degree is a predetermined value (voltage) using the detection signal (voltage) from the vacuum degree detection sensor 301 provided in the spectroscopic chamber 16. It is determined whether or not it is worse than the F-PC window breakage monitoring vacuum degree (for example, it is 100 Pa (= F-PC window breakage monitoring vacuum degree) or more for a set value of 13 Pa). Step S
13). Then, as a result of the determination, when it is determined to be “normal” (that is, no leakage has occurred),
The series of processes ends.

On the other hand, if it is determined in step S13 that "abnormal" (that is, no leakage has occurred), the process proceeds to the following steps. First, in step S14, the main body 21 of the personal computer apparatus 2 is notified via the communication line 3 that gas (air) leakage or damage to the supply tube has occurred in the apparatus. As a result, the personal computer device 2 provided separately as an operating device (peripheral device) has a failure notification (feria), an example of which is shown in the attached FIG.
The screen is displayed as a message on the display device 22 (at the same time, a warning sound may be generated via a speaker).

Thereafter, the control unit 100 of the apparatus is applied with the high voltage Hv. (About 1200 to 1500 V) as described above, and if the state of poor vacuum continues due to gas (air) leakage, the first stage FET is damaged. The operation of the F-PC 400 that may end up being stopped is stopped. Specifically, F-
The application of the high voltage Hv. To the PC 400 is turned off (OF
F) (step S15). Further, all the vacuum exhaust valves in the main chamber and the auxiliary exhaust chamber are closed (step S16),
Further, the vacuum pump 300, which would otherwise be heated and damaged if it is operated as it is, is stopped (so-called OFF), and a series of processes is ended.

In the above embodiment, the above step S
The degree of vacuum in the main chamber at 13 is "normal" or "abnormal"
It is realized by comparing the detection signal from the vacuum degree detection sensor 301 provided in the spectroscopic chamber 16 with a predetermined value (F-PC window break monitoring vacuum degree). The invention is not limited to this, and other detection methods can be adopted. For example, the rate of change of the degree of vacuum in the main chamber is calculated by utilizing the fact that the process shown in FIG. 1 is started at a constant cycle (that is, the rate of change of the degree of vacuum = | (previous vacuum degree) − (Current degree of vacuum) | / hour), whether the degree of vacuum in the main chamber is “normal” or “abnormal” depending on whether the calculated rate of change in degree of vacuum is a predetermined value or more. It is also possible to determine Also,
By changing the predetermined value of the vacuum degree change rate to be compared, including the predetermined value (F-PC window breakage monitoring vacuum degree), and setting it, the detection sensitivity for the abnormality of the vacuum degree can be changed as necessary. This is preferable because it can be freely set.

[0028]

As is apparent from the above detailed description, according to the present invention, the X
Gas (air) due to damage to the proportional coefficient tube, which is a line detector
When a vacuum failure state caused by a leak occurs, it is reliably detected and the operation of the device or parts that may be damaged is stopped, and the relatively expensive fluorescent X due to the adverse effect of this vacuum failure state. It has an excellent effect that the line analysis device can be protected safely and surely.

[Brief description of drawings]

FIG. 1 is a flowchart showing a vacuum degree abnormality detection / protection operation, which is a feature of an X-ray fluorescence analyzer of the present invention.

FIG. 2 is a perspective view showing an appearance of the X-ray fluorescence analyzer according to the present invention.

FIG. 3 is a block diagram showing an internal configuration of the X-ray fluorescence analyzer according to the present invention.

FIG. 4 is a partial cross-sectional view showing an example of the internal configuration of the X-ray fluorescence analyzer of the present invention.

FIG. 5 is a perspective view showing the external appearance of a gas flow type proportional coefficient tube which is an example of the X-ray detector of the X-ray fluorescence analyzer according to the present invention.

FIG. 6 is a cross-sectional view showing an internal configuration of the gas flow type proportional coefficient tube.

FIG. 7 is a diagram showing an example of a failure notification (feria) screen in the X-ray fluorescence analyzer according to the present invention.

[Explanation of symbols]

1 Device Main Body of X-ray Fluorescence Analyzer 2 Personal Computer Device as Operation (Peripheral) Device 13 Sample Chamber 14 X-ray Tube 17 22 Display Device 100 Control Unit 101 I / O Device 300 Vacuum Pump 301 Vacuum Degree Detection Sensor 400 Gas Flow type proportional coefficient tube (F-PC) SH sample holder

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 23/00-23/227 G01T 1/00-7/12

Claims (7)

(57) [Claims] 1. A sample is placed in a sample chamber kept at a predetermined vacuum degree by a vacuum degree control means, irradiated with X-rays from an X-ray tube, and fluorescent X-rays generated from the sample are converted into the vacuum. X-ray analysis device for analyzing the sample by performing spectroscopy by the spectroscopy means provided in the spectroscopy chamber maintained at a predetermined vacuum degree by the temperature control means, measuring the intensity of the dispersed fluorescence X-rays by the X-ray detector, and analyzing the sample. In which the means for detecting the degree of vacuum in the main chamber including at least the spectroscopic chamber is provided: the X-ray detector at least fills the inside thereof with a gas and partially emits fluorescence. A detector having a window for guiding X-rays to the inside is included, and an abnormality in the degree of vacuum in the main chamber is detected based on the degree of vacuum from a degree-of-vacuum detecting means provided in the main chamber. However, when the abnormality is detected, It stops the operation of the serial vacuum control means stopping the application of high voltage X-ray fluorescence spectrometer according to claim to the X-ray detector. 2. The fluorescent X-ray analysis apparatus according to claim 1, wherein the control means determines an abnormality in the degree of vacuum in the main chamber and a degree of vacuum from a vacuum degree detecting means provided in the main chamber. An X-ray fluorescence analyzer characterized by detecting by comparing with the value of. 3. The fluorescent X-ray analysis apparatus according to claim 1, wherein the control unit determines whether the vacuum degree in the main chamber is abnormal based on the vacuum degree from a vacuum degree detecting unit provided in the main chamber. An X-ray fluorescence analyzer, characterized in that a vacuum degree change rate is calculated by detecting the vacuum degree change rate by comparing the calculated vacuum degree change rate with a predetermined vacuum degree change rate. 4. The fluorescent X-ray analyzer according to claim 1, wherein the control means, when detecting an abnormality in the degree of vacuum in the main chamber, displays an abnormality in the degree of vacuum in the spectroscopic chamber. An X-ray fluorescence analyzer characterized by: 5. The fluorescent X-ray analysis apparatus according to claim 4, wherein the display of the abnormality of the vacuum degree in the spectroscopic chamber is provided in a peripheral device that is configured separately from the fluorescent X-ray analysis apparatus. An X-ray fluorescence analyzer characterized by being displayed above. 6. The fluorescent X-ray analyzer according to claim 2, wherein a predetermined value compared to detect an abnormal vacuum degree in the main chamber is variable. Analysis equipment. 7. The fluorescent X-ray analyzer according to claim 3, wherein a predetermined vacuum degree change rate for detecting an abnormal vacuum degree in the main chamber is variable. Analysis equipment.