JP2010038560A - Element analyzer and element analysis method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To analyze more elements by using a LIBS (Laser-induced Breakdown Spectroscopy) method. <P>SOLUTION: This element analyzer has a laser light oscillator 1 for generating pulse laser light 3 generating plasma when being irradiated to a sample 16, a laser light condensing part constituted so as to be able to condense light in a domain whose maximum diameter is 50-200 μm on the sample surface 16a by a laser light condensing lens 6, and a laser light irradiation part for irradiating light onto a light condensing domain on the sample surface 16a. A sample arrangement part 15 in which the atmosphere of the sample surface 16a is held airtightly, constituted so that the sample 16 can be installed inside, and receiving laser light irradiation, is arranged on the laser light irradiation side of the laser light irradiation part. The analyzer also has a fluorescence condensing part 13 for condensing fluorescence 22 discharged from a position separated as long as a prescribed distance in an optical axis direction from the sample surface 16a in the fluorescence 22 generated from the plasma 21, and a means for determining an element content based on the wavelength of the fluorescence 22 condensed by the fluorescence condensing part 13 and on the intensity of the wavelength. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elemental analysis apparatus using a laser-induced breakdown method and an analysis method thereof.

  Elemental analysis for detecting and quantifying various elements contained in a sample is a technique used in many fields. For example, in an iron and steel production line, managing impurity elements contained in products is an essential process.

  In elemental analysis of steel components, first, pig iron is sampled, and a sample is cut into a shape that can be measured by an analyzer. After that, for example, from light elements such as carbon (C) and sulfur (S) to heavy metal elements contained by a spark spectroscopic analyzer or the like are analyzed at a place different from the production line.

  In addition, in the evaluation of hydrogen embrittlement of metal materials, which will be a problem in the use of hydrogen energy, which is expected to expand in the future, development of rapid quantitative analysis technology of hydrogen (H) is desired. In this hydrogen analysis, a metal sample is sampled and cut into a shape suitable for the analyzer, and then burned at high temperature, and the components of the gas generated by this high temperature combustion are analyzed. Such elemental analysis methods require a lot of time for sampling, sample processing, and subsequent offline analysis.

  On the other hand, in the field of steel production and steel handling, there is a demand for a technique that can analyze the constituent elements in a short time on the line.

As one of the methods, laser-induced breakdown spectroscopy (hereinafter referred to as LIBS method) using laser light has been developed. In this LIBS method, as disclosed in, for example, Patent Document 1 and Patent Document 2, plasma is generated by directly irradiating a measurement sample with pulsed laser light. By analyzing the plasma light generated from this plasma and detecting the light emission of the wavelength unique to the atom, the kind of element, the amount of element, etc. in the sample can be detected. For this reason, sample pretreatment is unnecessary, and rapid and simple elemental analysis is possible.
JP 2004-205266 A JP 2000-310596 A

  The LIBS method uses fluorescence generated from an element as a measurement target. This fluorescence includes light emission unique to atoms emitted by atoms evaporated in the laser light irradiation region of the sample surface by laser light irradiation and light emission of atoms contained in the atmospheric gas.

  In the LIBS method, the laser beam is generally focused by one or more lenses, and the size of the irradiation region is generally about several hundreds of micrometers in diameter. Accordingly, the generated fluorescence is generated in this several hundred μm region.

  On the other hand, when the composition of the sample is a multi-component system, the element component ratio is often different in a minute region of several hundred μm or less. In addition, dendrites such as hydrides are formed in a minute region of 100 μm or less. In order to perform elemental analysis in such a minute region, it is necessary to make the laser irradiation region smaller.

  Further, depending on the element to be analyzed, it is also necessary to replace the atmosphere with a gas other than air. Elemental light emission in the emitted plasma light has a spatial distribution, and the position of high emission intensity differs depending on the analysis target element in the spatial position of the generated plasma. For this reason, in order to measure in detail the light emission of each element contained in the generated fluorescence, a fluorescence measurement device capable of setting fluorescence measurement conditions suitable for the analysis target element is required.

  The present invention has been made to solve the above problems, and an object of the present invention is to make it possible to analyze more elements with high accuracy using the LIBS method.

  In order to achieve the above object, an elemental analyzer according to the present invention is an elemental analyzer that analyzes the concentration of an element contained in a sample. A laser light oscillation device that generates laser light that generates plasma when irradiated on the sample; A laser beam transmitting unit that transmits the laser beam and the laser beam transmitted by the laser beam transmitting unit within a region having a maximum diameter of 50 μm or more and 200 μm or less on a sample surface by a laser beam focusing lens. A laser beam condensing unit configured to be condensable, a laser beam irradiating unit that irradiates the condensing region with the laser beam collected by the laser beam condensing unit, and a laser of the laser beam irradiating unit A sample placement unit arranged on the light irradiation side so that the sample can be placed therein, and the atmosphere of the sample surface receiving the laser beam irradiation is kept airtight; and a fluorescent light generated from the plasma Among the light, a fluorescence collector that collects fluorescence emitted from a position away from the sample surface by a predetermined distance in the optical axis direction, a wavelength of the fluorescence collected by the fluorescence collector, and this wavelength And means for quantifying the element content based on the strength of the element.

  The elemental analysis method according to the present invention is an elemental analysis method for analyzing the concentration of elements contained in a sample. The pulse laser beam is focused on the sample surface in a region having a maximum diameter of 50 μm or more and 200 μm or less. A condensing region adjusting step for adjusting the laser beam, a laser beam irradiation step for irradiating the condensing region with the pulsed laser light after the irradiation region adjusting step, and collecting a part of the fluorescence generated from the plasma light. A fluorescence detection step for emitting light, and an element analysis step for quantifying the element content of the condensed fluorescence.

  According to the present invention, it becomes possible to analyze more elements with high accuracy using the LIBS method.

  Hereinafter, an embodiment of an elemental analyzer according to the present invention will be described with reference to the drawings.

[First Embodiment]
A first embodiment of an elemental analyzer according to the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram showing the configuration of the elemental analyzer according to the first embodiment of the present invention. FIG. 2 is a front view showing details of the sample unit 15 and the fluorescence condensing unit 13 of FIG. FIG. 3 is a top view of FIG. FIG. 4 is a schematic top view showing a relative positional relationship between the sample 16, the fluorescent condensing lens 23, and the fluorescent transmission optical fiber 26. As shown in FIG. FIG. 5 is an elevational sectional view of the sample unit 15 of FIG.

  First, the structure of the elemental analyzer of this embodiment is demonstrated.

  The elemental analysis apparatus of the present embodiment is an apparatus for analyzing component elements contained on the surface of the solid sample 16 (sample surface 16a). This elemental analyzer has a laser oscillator 1, a laser power source 2, a timing controller 31, a fluorescence detector 27, and a measurement control computer 29.

  The laser oscillator 1 is an oscillator that oscillates pulsed laser light 3 such as a YAG laser. The laser oscillator 1 is connected to a laser power source 2. The laser power source 2 is connected to the timing controller 31. The fluorescence detector 27 is a device that detects fluorescence for performing elemental analysis, and is connected to the timing controller 31 via a measurement control computer 29.

  The elemental analysis apparatus also includes a laser light irradiation unit 10, a sample unit 15, a fluorescence condensing unit 13, and a monitor camera 33.

  The laser light irradiation unit 10 includes a reflection mirror 4 that reflects laser light and an optical axis adjustment mirror 5 that adjusts the optical axis. A part of the laser light irradiation unit 10 is fixed to the housing 12, and the condensing position of the dichroic mirror 11, the laser light condensing lens 6, and the pulsed laser light 3 can be adjusted in the housing 12. A fine movement stage 34 is arranged. In FIG. 1, illustration of a fixing method and the like of the dichroic mirror 11 is omitted.

  The dichroic mirror 11 has a characteristic of reflecting all or most of the pulsed laser light 3 incident thereon and transmitting a part of visible light.

  The laser beam condensing lens 6 has a function of condensing the incident pulse laser beam 3 on the sample surface 16a. The laser beam condensing lens 6 is configured so that the maximum diameter of the laser beam irradiation region of the sample surface 16a is about 50 μm by an 80 × objective lens used for an optical microscope, for example. When the 50 × objective lens is used, the maximum diameter of the irradiation region is about 80 μm, and when the 20 × objective lens is used, the maximum diameter is about 200 μm. In this embodiment, the 80 × objective lens is used to focus the pulsed laser light 3 on a relatively small area. Note that these three types of objective lenses with three magnifications can be attached, but the present invention is not limited to these.

  The monitor camera 33 is disposed above the dichroic mirror 11 and at a position facing the dichroic mirror 11. The monitor camera 33 has a function of correcting a shift of the focal position that occurs when the position of the laser beam condenser lens 6 is moved.

  The sample unit 15 is arranged on the downstream side of the pulse laser beam 3 in the laser beam irradiation unit 10. In the example of FIG. 1, it is arranged below the laser light irradiation unit 10. The sample unit 15 is a substantially rectangular parallelepiped container whose inside is kept airtight, and a sample holder 17 to which the sample 16 can be fixed is disposed. The sample holder 17 is attached to the sample holder fixing base 18. On the upper surface of the sample unit 15, a laser irradiation window 14 that is formed of, for example, optical glass and transmits laser light is provided.

  The fine movement stage 34 has a function of moving up and down in order to focus the laser beam condenser lens 6 on the sample surface 16a.

  Further, a buffer gas introduction port 19 for replacing the internal atmosphere with a desired buffer gas and a buffer gas exhaust port 20 for exhausting the internal buffer gas are formed on the side surface along the laser optical axis. Yes. In FIG. 1 and FIG. 2, detailed illustrations such as the opening positions of the buffer gas introduction port 19 and the buffer gas exhaust port 20 are omitted. As shown in FIGS. 4 and 5, the buffer gas inlet 19 is formed on the side surface of the sample unit 15, and the buffer gas exhaust port 20 is formed on the side surface opposite to the side surface on which the buffer gas inlet 19 is formed. Has been.

  In the sample unit 15, a buffer gas flow path configured so that buffer gas is supplied from the buffer gas inlet 19 and exhausted from the buffer gas outlet 20 is formed. The sample holder 17 is arranged so that a plurality of samples 16 to be analyzed can be installed on the bottom surface of the buffer gas flow path. 4 and 5 show an example in which three samples 16 are arranged along the flow path of the buffer gas.

  When the moisture in the sample unit 15 is removed to detect hydrogen or oxygen in the sample 16, for example, He gas or the like is used as the buffer gas.

  On both side surfaces of the sample unit 15 perpendicular to the buffer gas introduction port 19, a fluorescence observation window 25 that allows the fluorescence of the laser-generated plasma 21 generated by laser light irradiation to pass through the fluorescence condensing unit 13 is formed. These fluorescence observation windows 25 are formed so as to face each other.

  In addition, a heater (not shown) such as a cartridge heater or a sheathed heater can be attached in the sample unit 15. Although not shown, the heater is configured so that it can be installed in the sample unit 15 from the heater insertion hole 37 formed on the side surface of the sample unit 15 shown in FIG.

  The fluorescent light collecting unit 13 supports the fluorescent light collecting lens 23, the fluorescent light transmitting optical fiber 26 that guides the fluorescent light collected by the fluorescent light collecting lens 23 to the fluorescent light detector 27, and the fluorescent light transmitting optical fiber 26. The fluorescent transmission optical fiber sleeve 24 and the fluorescent transmission optical fiber sleeve 24 are fixed. 2 to 4 show an example having two fluorescent condensing lenses 23. In FIG. 1, only one fluorescent condenser lens 23 is shown, and the other fluorescent condenser lens 23 is omitted.

  As shown in FIG. 2, the fluorescence condensing unit 13 has an arm 13 a extending in a direction (horizontal direction) substantially perpendicular to the optical axis of the pulsed laser light 3. The arm 13 a is connected to a ring 13 b that surrounds the outer frame of the laser beam condenser lens 6.

  The arm 13a is provided with a support column 36 for fixing the two fluorescent condensing lenses 23 respectively. The two fluorescent condensing lenses 23 are arranged side by side in the horizontal direction, and their optical axes are arranged substantially parallel to the arm 13a, that is, in the horizontal direction.

  The support column 36 for fixing the fluorescent condensing lens 23 is configured to be movable in the horizontal direction along the arm 13a. The support 36 is fixed by a fixing screw 35 or the like after the position to be fixed by moving horizontally is determined.

  These fluorescent condensing lenses 23 are configured such that the focal point can be adjusted by horizontally moving the column 36 along the arm 13a. The focal points of the fluorescent condenser lenses 23 are set so as to fit inside the sample unit 15 through the fluorescence observation window 25 formed on one side surface of the sample unit 15.

  At a position facing the fluorescent light collecting lens 23 far from the sample unit 15, a fluorescent transmission optical fiber 26 into which the fluorescent light collected by the fluorescent light collecting lens 23 enters is disposed. As described above, the fluorescence transmission optical fiber 26 is supported by the fluorescence transmission optical fiber sleeve 24, and the fluorescence transmission optical fiber sleeve 24 is fixed by the fixing sleeve 38. The fixing sleeve 38 is attached to the arm 13a via a support column 36 by a fixing screw 35 or the like.

  Since the arm 13a is connected to a ring 13b that surrounds the outer frame of the laser beam condenser lens 6, when the laser beam condenser lens 6 is moved in the vertical direction by the fine movement stage 34 or the like, the fluorescence is accompanied by the vertical movement. The entire light collecting unit 13 is also configured to be movable up and down.

  As shown in FIG. 2, the fluorescent condensing lens 23 allows an image of the laser-produced plasma 21 from the sample 16 generated by irradiating the pulsed laser light 3 to be incident on the incident surface of the optical fiber 24 for fluorescent transmission. An image is formed at an enlargement ratio, and only light at a specific place of desired plasma light is guided to the fluorescence detector 27. In FIG. 2, the illustration of the pulsed laser light 3 near the sample surface 16a is omitted.

  In this elemental analysis device, the alignment illuminator 7 for assisting the focusing of the pulse laser beam 3 and the alignment illumination light 8 generated by the alignment illuminator 7 are irradiated onto the sample surface 16a and the like. A half mirror 9 is provided.

  Next, the flow of pulse laser light will be described.

  The pulsed laser light 3 oscillated from the laser oscillator 1 is reflected by the reflecting mirror 4 and the optical axis adjusting mirror 5 and is incident on the dichroic mirror 11 with the laser optical axis substantially horizontal. The dichroic mirror 11 reflects the horizontally incident pulsed laser light 3 by 90 degrees to change the optical path in the vertically downward direction.

  The pulse laser beam 3 reflected by the dichroic mirror 11 and whose optical path is changed vertically downward is condensed on the sample surface 16 a by the laser beam condensing lens 6.

  Since the dichroic mirror 11 has the characteristic of transmitting visible light, it can transmit the plasma light of the laser-generated plasma 21 generated when the sample surface 16a is irradiated with the pulsed laser light 3. Therefore, the laser generated plasma 21 and the like can be observed with the monitor camera 33.

  The laser oscillator 1 irradiates the sample surface 16a with pulsed laser light 3 having one pulse energy of about 1 mJ and a pulse width of about 5 ns. In this case, the output of one pulse of the pulse laser beam 3 is about 0.2 MW.

  Normally, the laser-generated plasma 21 is not formed even when the sample surface 16a is irradiated with the pulse laser beam 3 having such an intensity. When this is condensed to a size of several μm to several hundred μm by the laser light condensing lens 6, a part of the sample surface 16 a becomes plasma exceeding a so-called breakdown threshold. In this case, for example, by using an 80 × objective lens, the laser-produced plasma 21 can be formed by setting the maximum diameter of the irradiation region to about 50 μm.

  When the laser-generated plasma 21 is generated in this way, the laser-generated plasma 21 starts recombination with the end of the irradiation of the pulsed laser beam 3, and the constituent elements on the sample surface 16a are excited for several μs to several tens of μs. It becomes an atom of a state. The atom in the excited state emits fluorescence 22 proportional to the number of atoms when transitioning to the lower level.

  Of the fluorescence 22, only the fluorescence generated in the measurement region of the laser-generated plasma 21 is condensed by the fluorescence condenser lens 23 of the fluorescence condenser unit 13, and the fluorescence detector 27 is passed through the fluorescence transmission optical fiber 26. To enter. The fluorescence 22 that has entered the fluorescence detector 27 is converted into an electrical signal by information on the wavelength of the fluorescence 22 and the intensity of the wavelength. The fluorescence signal 28 converted into the electrical signal is transmitted to the measurement control computer 29.

  The measurement control computer 29 transmits a fluorescence measurement gate signal 30 delayed by a predetermined time from the timing signal 32 output from the timing controller 31. By these signal transmissions, the measurement control computer 29 measures only the fluorescence 22 generated in a specific time zone after the laser light irradiation and performs elemental analysis of the fluorescence 22.

  As can be seen from the above description, in this embodiment, the region for analyzing the element to be measured is set on the sample surface 16a so as to be a very small region having a maximum diameter of about several hundred μm, and the laser-generated plasma 21 is obtained. The measurement area and measurement time of the fluorescence 22 are optimized. Thereby, the fluorescence 22 at a specific position in the laser-produced plasma 21 is measured in a specific time zone after irradiation with the pulse laser beam 3.

  Thereby, the fluorescence 22 emitted from the element to be measured in the minute region of the sample surface 16a can be measured with high sensitivity and high S / N (signal to noise ratio), and laser-induced breakdown spectroscopy in the minute region. Elemental analysis is possible. Therefore, it becomes possible to analyze more types of elements with high accuracy.

  When analyzing the components of hydrogen and oxygen in the sample 16 with high accuracy, it is necessary to eliminate the influence of moisture present in the air. According to the elemental analyzer of this embodiment, the buffer gas is continuously supplied from the buffer gas inlet 19 into the sample unit 15 and then exhausted from the buffer gas outlet 20, thereby replacing the sample unit 15 with the buffer gas. can do. By substituting the buffer gas for the atmosphere in which the sample 16 is installed, it becomes possible to eliminate the influence of moisture and the like present in the air.

  In general, a large amount of moisture is adsorbed on the sample surface 16a placed in the air, and this moisture greatly hinders measurement. According to the present embodiment, before the sample 16 is irradiated with laser, the heater attached in the sample unit 15 can remove moisture adhering to the sample unit 15 and the sample surface 16a. With this heater, it becomes possible to reduce the influence of moisture and the like, and element analysis in the sample can be performed with higher accuracy.

  Further, according to the elemental analysis apparatus of the present embodiment, the state in which the pulse laser beam 3 is applied to the sample surface 16a is visually confirmed (monitored) by the fluorescence observation window 25 formed farther from the fluorescence condenser lens 23. )can do. While monitoring with one fluorescence observation window 25, the light can be condensed onto the fluorescence collection lens 23 via the other fluorescence observation window 25 on the side close to the fluorescence collection lens 23.

  Thereby, the irradiation state of the pulse laser beam 3 can be easily confirmed.

  In the laser beam irradiation unit 10, it is important to evaluate the correlation between the position where the sample laser beam 3 is irradiated with the pulse laser beam 3 and the fluorescence 22 generated at this position. According to the present embodiment, since the optical system (objective lens) used in the optical microscope is used for the laser light condensing lens 6, the laser light condensing lens 6 can also be used as an optical microscope. Therefore, the laser light condensing lens 6 can easily set in advance the position to be analyzed on the sample surface 16a.

  In addition, the monitor camera 33 can monitor the state of irradiating the sample laser beam 3 to the sample surface 16a. With this monitor camera 33, it is possible to set in advance the position to be analyzed on the sample surface 16a.

  By these methods, the aim of irradiating the pulse laser beam 3 to the set position on the sample surface 16a can be easily adjusted. Elemental analysis is performed by irradiating the pulse laser beam 3 while aiming at the set position. Even after the measurement, the state of the irradiation region of the sample surface 16a can be confirmed again by the optical microscope or the monitor camera 33.

  In the laser beam irradiation unit 10, it is necessary to strictly adjust and set the condensing position of the pulse laser beam 3 and the height position of the fluorescence measurement in the laser beam axis direction. In addition, for mapping the element distribution on the sample surface 16a, it is important to grasp the exact position of the sample surface 16a. In the present embodiment, the precise position of the measurement sample can be set by the fine movement stage 34.

  In the present embodiment, the ring 13 b of the fluorescent light collecting unit 13 is attached to the outer frame of the laser light collecting lens 6. Therefore, even when the sample unit 15 is moved up and down by the fine movement stage 34 in order to adjust the focus of the laser beam condenser lens 6, the spatial relative position between the laser beam condenser lens 6 and the fluorescence condenser unit 13. Is retained. This makes it possible to maintain a position where the fluorescence 22 can be detected with high sensitivity.

[Second Embodiment]
A second embodiment of the elemental analyzer according to the present invention will be described with reference to FIGS. FIG. 6 is a front view showing a part of the configuration of the elemental analyzer of the present embodiment. FIG. 7 is a top view of FIG. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In the present embodiment, the fluorescent light is directly incident on the fluorescent transmission optical fiber 26 without using the fluorescent light collecting lens 23 (FIGS. 1 to 4). Some elements to be analyzed can enter the fluorescence transmission optical fiber 26 without using the fluorescence condensing lens 23.

  As a result, the elemental analyzer can be further simplified and analyzed more efficiently.

[Third Embodiment]
A third embodiment of the elemental analyzer according to the present invention will be described with reference to FIG. FIG. 8 is a block diagram showing the configuration of the elemental analyzer according to the third embodiment of the present invention. In addition, this embodiment is a modification of 1st Embodiment, Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is abbreviate | omitted.

  In the present embodiment, the pulsed laser light 3 generated by the laser oscillator 1 is incident on the laser light transmission optical fiber 41 via the optical fiber incident optical system 39. The pulsed laser light 3 is incident on the collimator lens 40 through the laser light transmission optical fiber 41. The pulse laser beam 3 that has passed through the collimator lens 40 is reflected by the dichroic mirror 11 and irradiated onto the sample surface 16a as in the first embodiment.

  Thereby, it is possible to perform elemental analysis on the spot even for an analysis target in a place where the laser oscillator 1 is difficult to bring.

[Other Embodiments]
The description of the above embodiment is an example for explaining the present invention, and does not limit the invention described in the claims. Moreover, each part structure of this invention is not restricted to these embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

In the first to third embodiments described above, the YAG laser oscillator is applied to the laser oscillator 1, but the present invention is not limited to this. For example, an excimer laser or a CO ₂ laser can be used as long as it is a pulse laser capable of laser breakdown.

  It is also possible to combine the features of the first to third embodiments. For example, an optical fiber that is a feature of the third embodiment can be used for the elemental analysis apparatus of the second embodiment.

It is a block diagram which shows the structure of the elemental analyzer of 1st Embodiment which concerns on this invention. It is a front view which shows the detail of the sample unit of FIG. 1, and a fluorescence condensing unit. FIG. 3 is a top view of FIG. 2. It is a schematic top view which shows the relative positional relationship of the sample of FIG. 1, a fluorescence condensing lens, and the optical fiber for fluorescence transmission. FIG. 3 is a schematic vertical sectional view of the sample unit in FIG. 2. It is a front view which shows a part of structure of the elemental analyzer of 2nd Embodiment which concerns on this invention. FIG. 7 is a top view of FIG. 6. It is a block diagram which shows the structure of the elemental analyzer of 3rd Embodiment which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser oscillator, 2 ... Laser power supply, 3 ... Pulse laser beam, 4 ... Reflection mirror, 5 ... Optical axis adjustment mirror, 6 ... Laser beam condensing lens, 7 ... Alignment illuminator, 8 ... Alignment illumination light, DESCRIPTION OF SYMBOLS 9 ... Half mirror, 10 ... Laser beam irradiation unit, 11 ... Dichroic mirror, 12 ... Case, 13 ... Fluorescence condensing unit, 13a ... Arm, 13b ... Ring, 14 ... Laser irradiation window, 15 ... Sample unit, 16 ... Sample: 16a ... Sample surface, 17 ... Sample holder, 18 ... Sample holder fixing base, 19 ... Buffer gas introduction port, 20 ... Buffer gas discharge port, 21 ... Laser generated plasma, 22 ... Fluorescence, 23 ... Fluorescence condenser lens, 24 ... Fluorescence transmission optical fiber sleeve, 25 ... Fluorescence observation window, 26 ... Fluorescence transmission optical fiber, 27 ... Fluorescence detector, 28 ... Fluorescence signal, 29 ... Measurement control 30 ... Gate signal 31 ... Timing controller 32 ... Timing signal 33 ... Monitor camera 34 ... Fine motion stage 35 ... Fixing screw 36 ... Pilting column 37 ... Heater insertion hole 38 ... Fixing sleeve 39 ... Light Fiber incident optical system, 40 ... collimator lens, 41 ... optical fiber for laser beam transmission

Claims (13)

In an elemental analyzer that analyzes the concentration of elements contained in a sample,
A laser beam oscillation device for generating a laser beam that generates plasma when irradiated on the sample;
A laser beam transmission unit for transmitting the laser beam;
A laser beam condensing unit configured to be capable of condensing the laser beam transmitted by the laser beam transmitting unit on a sample surface within a region having a maximum diameter of 50 μm or more and 200 μm or less by a laser beam condensing lens. When,
A laser beam irradiation unit that irradiates the laser beam focused by the laser beam focusing unit to the focusing region;
A sample placement unit arranged on the laser beam irradiation side of the laser beam irradiation unit, configured to be able to install the sample therein, and holding the atmosphere of the sample surface receiving the laser beam irradiation in an airtight manner;
A fluorescence condensing unit that condenses fluorescence emitted from a position separated from the sample surface by a predetermined distance in the optical axis direction among the fluorescence generated from the plasma;
A means for quantifying the element content based on the wavelength of the fluorescence condensed by the fluorescence condensing unit and the intensity of the wavelength;
An elemental analysis apparatus characterized by comprising: The sample placement part is:
A buffer gas supply port for supplying a buffer gas for replacing the atmosphere in the sample placement portion;
A buffer gas discharge port for discharging the buffer gas in the sample placement portion;
The elemental analysis apparatus according to claim 1, comprising:   The element analyzer according to claim 1, wherein the sample placement unit is formed with a plasma observation window that is visible from a direction intersecting the plasma in the optical axis direction.   The said sample arrangement | positioning part is equipped with the heater for heating the inside of the said sample arrangement | positioning part and removing the water | moisture content adhering to the said sample, The Claim 1 thru | or 3 characterized by the above-mentioned. Elemental analysis equipment.   The element analyzer according to any one of claims 1 to 4, wherein the sample surface is configured to be observable through the laser beam condensing lens.   The element analyzer according to claim 1, further comprising a sample moving mechanism configured such that the sample surface is movable along the optical axis direction. A dichroic mirror that is disposed so as to intersect the optical path of the laser beam, reflects a predetermined wavelength band, and transmits a part of visible light;
A monitoring camera disposed on the opposite side of the sample with respect to the dichroic mirror;
Have
The element analyzer according to claim 1, wherein the sample camera and the plasma are configured to be visually recognized by the monitor camera.   The fluorescent light condensing unit and the laser light condensing lens are fixed to each other, and fixed so that a relative position between the position where the fluorescent light is condensed and the laser light condensing position is maintained at a predetermined distance. The elemental analyzer according to any one of claims 1 to 7, characterized by: In the fluorescence condensing part, a plurality of fluorescent condensing lenses are arranged,
The image of the plasma is formed on the incident surface of the optical fiber for fluorescence spectroscopy at a predetermined magnification by the lens for condensing fluorescence, and only the fluorescence in a predetermined region is guided to the optical fiber for fluorescence spectroscopy. The elemental analyzer according to any one of claims 1 to 8, wherein the elemental analyzer is provided.   The element analyzer according to any one of claims 1 to 9, wherein the laser transmission unit is configured to transmit the laser light by an optical fiber. In an elemental analysis method for analyzing the concentration of elements contained in a sample,
A condensing region adjusting step for adjusting the pulsed laser light so as to condense in a region having a maximum diameter of 50 μm or more and 200 μm or less on the sample surface;
After the irradiation region adjustment step, a laser beam irradiation step of irradiating the focused laser beam to the pulsed laser beam,
A fluorescence detection step of collecting a part of the fluorescence generated from the plasma light;
An elemental analysis step for quantifying the content of the condensed fluorescent element;
An elemental analysis method characterized by comprising:   The element analysis method according to claim 11, further comprising a sample surface observation step of observing the sample surface with a laser beam condensing lens for condensing the laser beam.   The elemental analysis method according to claim 12, wherein the elemental analysis step and the sample surface observation step are performed in parallel.

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