JPH10221276A - X-ray analyzing device with opened irradiation chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray analyzing device which can certainly prevent X-ray irradiation by mistake in case no specimen exists in an irradiation window. SOLUTION: An X-ray analyzing device has an irradiation chamber 6 which contains an X-ray source 4 to irradiate a specimen 3 with the primary X-rays 1 and a sensor 5 to sense the secondary X-rays 2 given by the specimen 3, and an irradiation window 8 opening in a case 7 to bound the chamber 6 is covered by the specimen 3 positioned outside the chamber 6. A judging means 20 judges that the intensity of the X-rays sensed by the sensor 5 is over the specified level, while a holding means 24 continues the irradiation of the specimen 3 from rays given by the source 4 if the obtained intensity exceeds the specified level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open-irradiation room X-ray analyzer for irradiating a sample placed on an irradiation window of an irradiation room with X-rays from an X-ray source in the irradiation room. is there.

[0002]

2. Description of the Related Art When performing X-ray analysis on a curved steel plate or an irregular-shaped sample whose shape cannot be specified, the sample is irradiated with primary X-rays into an irradiation chamber with an irradiation window opened. An X-ray analyzer with an open irradiation chamber is used in which an X-ray source and a detector for detecting secondary X-rays from a sample are provided, and the sample is placed on an irradiation window to perform X-ray analysis. In this X-ray analyzer, X-rays can be prevented from leaking out of the irradiation chamber by placing the sample on the irradiation window and performing X-ray analysis. However, there is a possibility that X-ray irradiation may be performed without the sample placed on the irradiation window. In order to avoid this, a switch for confirming the placement of the sample, which is activated when a sample is placed on the irradiation window, is installed, and an interlock may be configured so that X-ray irradiation cannot be performed unless the switch is activated. .

However, in such an X-ray analyzer, it is difficult to install a switch so that the switch operates with a sample placed on the irradiation window, even when analyzing an irregular-shaped sample of any shape. It is.

The present invention has been made in view of the above-mentioned conventional problems, and provides an open-irradiation-type X-ray analyzer capable of reliably preventing X-rays from being erroneously irradiated when there is no sample in an irradiation window. The purpose is to do.

[0005]

In order to achieve the above-mentioned object, an open-irradiation-type X-ray analyzer according to the first aspect of the present invention is applied to a sample having one or more samples.
An X-ray source for irradiating a secondary X-ray and a detector for detecting secondary X-rays from the sample are housed in an irradiation chamber, and an irradiation window opened in a case forming the irradiation chamber is provided in the irradiation chamber. In addition to the configuration that is covered by the sample located on the outside, a determination unit that determines that the intensity of the X-ray detected by the detector is equal to or higher than a predetermined level, and when the intensity is equal to or higher than a predetermined level, Holding means for continuously irradiating the sample from the X-ray source.

According to the X-ray analyzer of the present invention, when an X-ray source irradiates a sample with primary X-rays while the irradiation window of the irradiation chamber is covered with the sample, Since the secondary X-rays from the sample are detected by the detector, the determination means determines that the intensity of the detected X-rays is equal to or higher than a predetermined level, and in response to this determination, the holding means causes the holding means to detect the intensity of the sample from the X-ray source Continue irradiation to When the irradiation window of the irradiation room is not covered with the sample, the detector does not detect the secondary X-ray from the sample even if the primary X-ray is irradiated from the X-ray source. Is lower than a predetermined level, and in response to this determination, the holding unit stops continuation of X-ray irradiation from the X-ray source. Thereby, it is possible to prevent the X-ray from being emitted to the outside due to the X-ray irradiation being performed without the sample in the irradiation window.

According to a second aspect of the present invention, there is provided an X-ray analyzer having an open irradiation chamber, wherein the X-ray source includes a shutter for opening and closing a primary X-ray passage. The holding means holds the shutter in an open state. According to this configuration, when the irradiation window is covered with the sample, the open state of the shutter is held by the holding unit, the irradiation of the primary X-ray to the sample is continued, and the irradiation window is covered with the sample. If not,
The shutter open state by the holding means is released, and 1
Next X-ray irradiation is stopped.

According to a third aspect of the present invention, in the first embodiment, the holding means holds the operating state of the X-ray source. According to this configuration, when the irradiation window is covered by the sample, the operating state of the X-ray source is held by the holding means, the irradiation of the primary X-ray to the sample is continued, and the irradiation window is If not, the holding of the operating state of the X-ray source by the holding means is released, and the irradiation of the sample with the primary X-ray is stopped.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing a schematic configuration of an irradiation room open type X-ray analyzer according to one embodiment of the present invention. The X-ray analyzer with open irradiation chamber includes an X-ray source 4 for irradiating a sample 3 with primary X-rays 1 and a secondary X-ray 2
And a detector 5 for detecting the light is housed in an irradiation chamber 6. An irradiation window 8 is opened in a case 7 forming the irradiation chamber 6, and the irradiation window 8 is mounted from outside the irradiation chamber 6. Is covered by the sample 3 to be placed.

The X-ray source 4 includes an X-ray tube 9 and a shutter 10. In the tube 11 of the X-ray tube 9, a filament 13 is provided.
And a target 14 are housed therein.
Is applied with a high voltage. The target 14 is excited by the collision of the electrons a emitted from the filament 13 and emits primary X-rays 1.
The light is radiated from the radiation window 15 provided on the peripheral wall toward the irradiation window 8 of the case 7. The shutter 10 is an X-ray tube 9
The opening and closing of the passage of the primary X-rays 1 radiated from the radiation window 15 is normally restricted to the closed state by the spring 16, and the solenoid 16 is opened by the operation of the solenoid 17 against the restoring force of the spring 16. Will be retained.

The detector 5 is a non-dispersive semiconductor detector, and is provided near the irradiation window 8 of the case 7.
A detection field limiting mask 18 is provided on the X-ray incidence side of the detector 5. Thus, only the secondary X-rays 2 from the sample 3 can be selectively detected. The detection field limiting mask 18
May be arranged such that the irradiation range of the primary X-ray 1 is limited within the irradiation window 8 in the middle of the irradiation path of the primary X-ray 1 as shown by a two-dot chain line.

The output terminal of the detector 5 is connected to an analysis circuit 19 and a judgment circuit 20. The analysis circuit 19 includes the detector 5
Is a circuit for analyzing the composition of the sample 3 based on the intensity of the secondary X-rays 2 detected in the step (a). The determination circuit 20 is a determination unit that determines that the X-ray intensity detected by the detector 5 is equal to or higher than a predetermined reference level. In this case, the reference level is lower than the X-ray detection intensity of the detector 5 when detecting the secondary X-ray 2 from the sample 3, and when the sample 3 is not in the irradiation window 8 of the case 7, the detector 5 The level is set higher than the X-ray detection intensity to be detected.

The solenoid 17 of the shutter 10 is connected to a shutter drive circuit 22 through a normally closed contact type switch 21. The shutter drive circuit 22 operates the solenoid 17 in response to an external start signal b. Further, a delay circuit 23 is connected to the determination circuit 20, and the delay circuit 23 activates the determination circuit 20 after a predetermined delay time τ has elapsed after receiving the start signal b. In this case, the delay time τ is set to a value corresponding to the time from when a high voltage is applied to the X-ray tube 9 from the power supply 12 to when the target 14 of the X-ray tube 9 is excited. The power supply 12 also operates upon receiving a start signal b from the outside. Solenodo 17,
The open state of the shutter 10 is held by the switch 21 and the shutter drive circuit 22 and the like.
Holding means 24 for continuously irradiating the primary X-ray 1 to the laser beam.

According to the irradiation room open type X-ray analyzer having the above-mentioned configuration, when the start signal b is input in a state where the irradiation window 8 is covered by the sample 3 outside the irradiation room 6,
The shutter 17 is operated by the shutter drive circuit 22 to open the shutter 10, and a high voltage is applied to the X-ray tube 9 from the power supply 12. Thereby, the X-ray tube 9
The primary X-ray 1 is emitted from the radiation window 15 toward the sample 3, and the secondary X-ray 2 from the sample 3 is detected by the detector 5.
When the start signal b is input, the primary X-ray 1
When the delay time τ sufficient to radiate the signal has elapsed, the delay circuit 23 activates the determination circuit 20. At this time, sample 3
Since the X-ray detection intensity of the detector 5 for detecting the secondary X-rays 2 from the above becomes equal to or higher than a predetermined reference level, a corresponding judgment output is output from the judgment circuit 20. This judgment output is output from the switch 21
Do not operate off. Therefore, the shutter drive circuit 22
, The operation of the solenoid 17 is continued, and the shutter 10 is maintained in the open state. That is, the irradiation of the primary X-rays 1 from the X-ray source 4 to the sample 3 is continued thereafter.

On the other hand, when the start signal b is input in a state where the irradiation window 8 is not covered by the sample 3, the shutter 10 is opened and the X-ray tube is 9 is applied with a high voltage. In this case, most of the primary X-rays 1 emitted from the emission window 15 of the X-ray tube 9 are emitted from the irradiation window 8 to the outside of the irradiation room 6. Therefore, the detector 5 does not detect the secondary X-rays 2 from the sample 3. When the delay time τ elapses from the input of the start signal b, the delay circuit 2
3 activates the decision circuit 20. At this time, since the X-ray detection intensity of the detector 5 becomes a value lower than the predetermined reference level,
The judgment circuit 20 outputs a corresponding judgment output.
This determination output turns off the switch 21. As a result, the operation of the solenoid 17 by the shutter drive circuit 22 stops, and the shutter 10 is returned to the closed state by the restoring force of the spring 16. Thus, when the delay time τ elapses after the input of the start signal b, the irradiation of the primary X-rays 1 from the X-ray source 4 is stopped, and the primary X-rays 1 are emitted from the irradiation window 8 to the outside of the irradiation chamber 6. Radiation can be prevented.

In the irradiation room open type X-ray analyzer, the detector 5 for X-ray analysis is used for safety confirmation without specially providing a detector for safety confirmation. The mechanism can be configured simply and inexpensively.

FIG. 2 is a conceptual diagram showing a schematic configuration of an irradiation room open type X-ray analyzer according to another embodiment of the present invention.
In this embodiment, the shutter 10 in the configuration of FIG.
The solenoid 17 and the shutter driving circuit 22 are omitted, a normally closed contact type switch 21 is interposed between the power supply 12 and the X-ray tube 9, and the switch 21 is turned off by the judgment output of the judgment circuit 20. It is. Analysis circuit 19,
The judgment circuit 20, the delay circuit 23 and the like are the same as those in the configuration of FIG. In this case, the switch 21 constitutes a holding unit 24 for continuing the X-ray irradiation from the X-ray source 4 to the sample 3.

According to the X-ray analyzer with open irradiation chamber,
When the irradiation window 8 is covered by the sample 3, the judgment circuit 2
The on state of the switch 21 is maintained by the determination output from 0, the power supply from the power supply 12 to the X-ray source 4 is continued, and the irradiation of the primary X-ray 1 from the X-ray source 4 to the sample 3 is continued. You.

On the other hand, when the irradiation window 8 is not covered with the sample 3, the switch 21 is turned off by the judgment output from the judgment circuit 20. As a result, X
The application of the high voltage to the X-ray tube 9 is stopped, and thereafter, the irradiation of the primary X-rays 1 from the X-ray source 4 is stopped, and the primary X-rays 1 are emitted from the irradiation window 8 to the outside of the irradiation chamber 6. Can be prevented.

In each of the above-described embodiments, the X-ray analysis apparatus has a configuration in which the sample 3 is placed on the irradiation window 8 and X-ray analysis is performed. The same function can be provided even if the same configuration is provided in a handy type open irradiation chamber X-ray analyzer that performs X-ray analysis by pressing against a sample 3 that is a stationary object.

In each of the above-described embodiments, an X-ray analyzer with an open irradiation chamber in which the detector 5 for detecting the secondary X-rays 2 from the sample 3 is of a non-dispersive type which does not require spectral analysis has been described. Even in the case of an X-ray analyzer with an open irradiation chamber in which the detector is of a dispersive type, the same configuration can be provided to provide the same function.

That is, the dispersion-type device includes a well-known goniometer that moves the spectroscope and the detector in a fixed angular relationship in accordance with the wavelength of the element to be analyzed in the sample. If the detector is at a position that does not match the wavelength of the element to be analyzed, the detector will detect only the background component of the X-ray (wavelength component other than the wavelength of the element to be analyzed), and the X-ray detection intensity Is considerably lower than when detecting the wavelength component of the element to be analyzed. However, even in this case, the X-ray detection intensity of the detector that detects the background component is the X-ray detection intensity detected by the detector when the irradiation window is not covered with the sample, that is, the secondary X-ray 2. The level is sufficiently high compared to the intensity of X-rays radiated from the wall of the case 7, etc., so by setting an appropriate judgment reference level, the X-ray detection intensity when there is a sample and the X-ray detection intensity when there is no sample Can easily be determined by the determination circuit.

[0023]

As described above, according to the present invention,
When the irradiation window of the irradiation chamber is not covered by the sample, X
Since the detector does not detect the secondary X-rays from the sample even when the primary X-rays are irradiated from the source, the determination means determines that the intensity of the detected X-rays is lower than a predetermined level, and responds to this determination. As a result, the holding means stops the continuation of the X-ray irradiation from the X-ray source, and the X-ray irradiation is performed without the sample in the irradiation window.
It is possible to reliably prevent the wire from leaking to the outside.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a schematic configuration of an irradiation room open type X-ray analyzer according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating a schematic configuration of an X-ray analyzer with an open irradiation chamber according to another embodiment.

[Explanation of symbols]

1 ... primary X-ray, 2 ... secondary X-ray, 3 ... sample, 4 ... X-ray source,
5 Detector, 6 Irradiation room, 7 Case, 8 Irradiation window, 1
0: shutter, 20: determination circuit (determination means), 24: holding means

Claims (3)

[Claims] An X-ray source for irradiating a sample with primary X-rays and a detector for detecting secondary X-rays from the sample are housed in an irradiation chamber, and are opened in a case forming the irradiation chamber. In an X-ray analyzer in which an irradiation window is covered by the sample located outside the irradiation chamber, X-rays detected by the detector
An irradiation chamber open type X-ray comprising: a determination unit for determining that the intensity of a ray is equal to or higher than a predetermined level; and a holding unit for continuing irradiation of the sample from the X-ray source when the intensity is equal to or higher than the predetermined level. Analysis equipment. 2. The method according to claim 1, wherein the X-ray source is a primary X-ray source.
A shutter for opening and closing a line passage, wherein the holding unit includes:
An open-irradiation-type X-ray analyzer for maintaining an open state of the shutter. 3. The X-ray analyzer of claim 1, wherein said holding means holds an operating state of said X-ray source.