JP2001343364A - Device for detecting specific atoms in solids - Google Patents

Abstract

(57) [Problem] To provide a specific atom detection device capable of detecting a trace amount of a specific atom with high sensitivity. An extraction electrode generates an extraction electric field in a space around an object to be measured. The ion transport path transports the ions extracted by the extraction electrode. An ion detector detects ions transported through the ion transport path. A laser light source causes a laser beam to enter the ion transport path so as to propagate in a direction opposite to the ion transport direction. The incident laser beam reaches the object to be measured and causes ablation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a specific atom in a solid, and more particularly to a device for detecting a specific atom in a scattered substance by ablation using a laser.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 10-48370 discloses a method of irradiating an ultraviolet laser to a surface of a material containing tritium to cause ablation and measuring the amount of scattered tritium. As a method of measuring the amount of the dispersed tritium, a method using quadrupole mass spectrometry, an ionization chamber or the like is exemplified.

[0003] Fusion reactors use deuterium (D) and tritium (T), which are hydrogen isotopes, as fuel. In order to cause a fusion reaction of these elements, it is necessary to maintain a plasma state of about 100 million degrees or more. The plasma is maintained by a magnetic field created in the vacuum vessel.
The material surface of the plasma-facing device facing the plasma is directly exposed to the fuel gas (D, T) and the plasma, and these elements dissolve into the material.

FIG. 8 is a diagram schematically showing a fuel flow around the core. Deuterium and tritium are supplied from a fuel injection device 52 into a vacuum vessel 51 surrounded by a superconducting coil 55. The inside of the vacuum vessel 51 includes a vacuum exhaust device 5.
3 is evacuated. A plasma 63 is generated in the internal space of the vacuum vessel 51, and the plasma is heated to a temperature of 100 million degrees or more by various excitation means. Vacuum vessel 51
A diverter plate 61 is attached to a part of the inner surface of. The diverter plate 61 neutralizes particles around the plasma. The fuel gas and its plasma come into direct contact with the vacuum vessel 51 and the diverter plate 61, so that the fuel gas element dissolves into the material.

[0005] On the other hand, tritium is a radioactive element, and it is necessary to know the amount of tritium contained in the material of the vacuum vessel 51 and the like for safety management of the whole fusion reactor. In the method disclosed in Japanese Patent Application Laid-Open No. H10-48370, tritium is extracted in a form that can be analyzed, and detected by quadrupole mass spectrometry or the like.

[0006]

In the method using quadrupole mass spectrometry, the sensitivity is low and it is difficult to detect a trace amount of a specific atom.

An object of the present invention is to provide a specific atom detecting device capable of detecting a trace amount of a specific atom with high sensitivity.

[0008]

According to one aspect of the present invention, there is provided an extraction electrode for generating an extraction electric field in a space around an object to be measured, an ion transport path for transporting ions extracted by the extraction electrode, An ion detector for detecting ions transported through the ion transport path, and a laser beam is incident on the ion transport path so as to propagate in a direction opposite to the transport direction of the ions, and reaches the object to be measured. A specific atom detection device having a laser light source that causes ablation to occur is provided.

When the object to be measured is arranged such that the surface thereof is perpendicular to the optical axis of the laser beam, the scattered matter from the object to be measured jumps out toward the ion transport path. The flying matter is ionized and transported in the ion transport path. The transported ions are detected by an ion detector. Since the flying objects fly out toward the ion transport path, ions can be efficiently introduced into the ion transport path.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing embodiments of the present invention,
With reference to FIG. 3 to FIG. 7, a description will be given of a specific atom detection device and detection principle related to the present invention.

FIG. 3 shows a schematic diagram of a detection device according to the present invention. The extraction electrodes 2a and 2b are arranged in the vacuum vessel 1. The extraction electrodes 2a and 2b are arranged substantially parallel to each other, and the measurement object 5 is held in a space sandwiched therebetween. A positive voltage is applied to one extraction electrode 2a,
A negative voltage is applied to the other extraction electrode 2b. With this voltage, an extraction electric field is generated in the space between the extraction electrodes 2a and 2b. Extraction electrode 2 to which negative voltage is applied
b is a mesh.

The laser emitted from the laser light source 10 is
The light is condensed by the lens 11, passes through the laser introduction window 13, and is introduced into the vacuum vessel 1. The laser introduced into the vacuum vessel 1 irradiates the object 5 to be measured. The optical axis of the laser introduced from the laser introduction window 13 is substantially perpendicular to the direction of the extracted electric field. The laser light source 10 is, for example, a wavelength-variable dye laser device. The lens 11 has a focal length of 300 m, for example.
m convex lens.

When the laser beam is applied to the measuring object 5, ablation occurs, and a part of the surface layer of the measuring object 5 is scattered. In the scattered substance, atoms constituting the object 5 to be measured,
Impurity atoms contained in the measurement object 5 and these ions are included. The positive ions are attracted to the mesh-shaped extraction electrode 2b by the extraction electric field, and
Is introduced into the time-of-flight mass spectrometer 20 attached to the camera.

FIG. 4 is a schematic sectional view of the time-of-flight mass spectrometer 20. Extraction electrodes 2a and 2b are arranged in the vacuum vessel 1, and a time-of-flight mass spectrometer 20 is arranged downstream (left side in FIG. 2) of the extraction electrode 2b.
The time-of-flight mass spectrometer 20 includes a vacuum duct 40, an accelerating electrode 25, a slit 26,
7, 28, micro channel plate (MCP) 29,
An anode (collector) 30 and an ammeter 31 are included.

An extraction electrode 2b is attached to the upstream opening of the vacuum duct 40. Acceleration electrode 25, slit 2
6, 27, 28, the MCP 29, and the anode 30 are arranged in this order from the upstream side to the downstream side.
For example, the distance L1 between the extraction electrode 2a and the ablation position P is 40 mm, and the ablation position P and the extraction electrode 2b
Is 10 mm. The interval L3 between the extraction electrode 2b and the acceleration electrode 25 is 30 mm, the interval L4 between the acceleration electrode 25 and the slit 26 is 114 mm, the interval L5 between the slit 26 and the slit 27 is 140 mm, and the slit 27 and M
The distance from the CP 28 is 70 mm.

The MCP 29 has a two-dimensional structure in which many thin glass pipes each having an inner wall as a resistor are bundled. Each glass pipe forms an independent secondary electron multiplier. When ions are incident from the incident side end of each glass pipe and collide with the inner wall, secondary electrons are emitted from the inner wall. A voltage is applied to both ends of the MCP 29, and the emitted secondary electrons are accelerated by an electric field generated by the voltage, collide again with the inner wall, and emit secondary electrons. This process is repeated along the glass pipe, and many secondary electrons are emitted from the output side.

For example, a potential of 0 V is applied to the extraction electrode 2a, a potential of -300V is applied to the extraction electrode 2b, and the acceleration electrode 25, the slits 26, 27, 28, and the MCP 2
9, a potential of -2300 V is applied to the inlet 29a,
A potential of -300 V is applied to the outlet 29b of P29 and the anode 30.

Positive ions in the scattered substance generated by ablation at the position P are attracted to the extraction electrode 2b, accelerated by the acceleration electrode 25, and
28, and enters the MCP 29. Secondary electrons corresponding to the amount of incident ions are emitted from the outlet 29b of the MCP 29. The secondary electrons are captured by the anode 30 and detected by the ammeter 31.

The speed of ions accelerated by the accelerating electrode 25 is proportional to q / m. Here, q is the charge amount of the ion, and m is the mass of the ion. MCP2 depending on ion species
Since the time required to reach 9 is different, ions contained in the scattered substance can be detected for each ion species. In addition, the ion concentration in the flying substance can be known from the magnitude of the ion current. That is, information on the concentration of the specific atom contained in the measurement object can be obtained.

Next, a method for detecting a specific atom in a solid object to be measured by using the detection apparatus shown in FIGS. 3 and 4 will be described. Here, a case will be described as an example in which deuterium contained in graphite into which deuterium is implanted is detected using an accelerator.

The measuring object 5 shown in FIG. 3 is irradiated with a pulse laser in the wavelength range of the excitation wavelength of deuterium. The laser used in the embodiment has an energy of 100 per pulse.
μJ, pulse repetition frequency 10 Hz, wavelength 243.
07 to 243.08 nm.

FIG. 5A shows a time-of-flight mass spectrometer 20.
Shows the signal strength obtained by The horizontal axis represents the flight time of ions in the unit of “μs”, and the vertical axis represents the signal intensity on an arbitrary scale. Flight time about 0.8 μs, about 1.1 μs, about 2.
At 3 μs, peaks corresponding to hydrogen ions (H ⁺ ), deuterium ions (D ⁺ ), and carbon ions (C ⁺ ) respectively appear. By determining the presence or absence of a peak corresponding to deuterium ions, the presence or absence of deuterium in an object to be measured can be determined. Further, by measuring the height of the peak, information on the concentration of deuterium contained in the measurement object can be obtained.

FIG. 5B shows that the laser wavelength is 243n.
The measurement results when m is shown. In this case, no peak corresponding to the deuterium ion appears. This is probably because the laser wavelength used was different from the excitation wavelength of the deuterium, so that the deuterium was hardly ionized and could not be detected by the time-of-flight mass spectrometer.

By using a laser having an excitation wavelength of deuterium as the laser for ablating the object to be measured, the object to be measured can be ablated and the deuterium can be efficiently ionized. For this reason, it becomes possible to detect a trace amount of deuterium with high sensitivity.

When the method according to the above embodiment is used,
It becomes possible to discriminate atoms or molecules having the same mass number. In general mass spectrometry, it is difficult to discriminate atoms or molecules having the same mass number. For example, since both T atoms and HD molecules have a mass number of 3, it is difficult to discriminate these two types of particles by a general mass spectrometry. In the case where the method according to the above embodiment is used, the ablation is performed using a laser beam having an excitation wavelength of one of the particles, so that the one particle can be detected preferentially.

In general, the excitation wavelength of deuterium coincides with the wavelength showing light absorption in the absorption spectrum of deuterium atoms when excited by one photon. When excited by a large number of photons, it becomes an integral multiple of the absorption wavelength. However, in the case of this embodiment, the excitation wavelength of deuterium slightly deviates from the wavelength at which absorption is shown in the absorption spectrum of deuterium atoms, as described later.

The wavelength λ of the absorption spectrum of the hydrogen atom is

[0028]

1 / λ = R (1 / m ² −1 / n ² ) Where R is the Rydberg constant and m is
1, 2, 3,..., N are m + 1, m + 2, m + 3,.
・ ・In the above equation, if m = 1 and n = 2, λ (1,2) ≒ 121.5 nm. The wavelengths 243.07 to 243.08 nm of the laser used in the examples are
This corresponds to a wavelength approximately twice as long as the excitation wavelength λ (1, 2).

Here, the Rydberg constant R is proportional to the reduced mass u of the atom. Also, the reduced mass u of hydrogen isotope
, When the mass of the nuclei was N, the electron mass and m _e,

[0030]

[Number 2] expressed as 1 / u = 1 / N + 1 / m e. Approximating the masses of protons and neutrons to be equal, and letting it be M, N = M for H and N for D
= 2 × M, and in the case of T, N = 3 × M. Using this reduced mass, the relationship between the excitation wavelength of each of the isotopes D and T and the excitation wavelength of H can be determined. M = 1000MeV
_{^{/ C 2, m e = 0.5MeV}} / C 2, H the excitation wavelength of 24
Assuming 3.13 nm, the excitation wavelength of D is 243.07 n
The excitation wavelengths of m and T are 243.05 nm.

In the above embodiment, the laser for ablation also serves as the laser for ionizing deuterium, but the laser for ablation and the laser for ionization may be separated. In this case, the wavelength of the laser for ionization is set as the excitation wavelength of deuterium.

FIG. 6 shows the relationship between the wavelength of the laser and the height of the peak corresponding to the deuterium ion. The horizontal axis represents the wavelength of the laser in the unit of “nm”, and the vertical axis represents the signal intensity obtained by the time-of-flight mass spectrometer on an arbitrary scale. The solid line in FIG. 6 shows a case where deuterium is detected by a method of causing ablation by irradiating graphite with a laser using the above-described detection device, and the dashed line irradiates a gas containing deuterium with a laser for ionization. This shows the case where deuterium is detected.

When deuterium in a gas is detected, a peak appears at a wavelength of about 243.069 nm. On the other hand, when deuterium is detected by ablation, the peak becomes broad and the wavelength giving the maximum value is about 243.076 nm. From the graph of FIG. 6, when deuterium in a solid is detected by causing ablation, the wavelength of the laser is set to 24.
It turns out that it is preferable to set it to 3.070 to 243.081 nm. Although the reason is not clear, in the case of detecting deuterium in solids using the ablation phenomenon, and in the case of detecting deuterium in gas,
It was found that the optimum wavelength of the laser used was different.

Next, a method of measuring the concentration distribution of deuterium in the depth direction of the object to be measured will be described. A specific portion of the surface of the measurement object was repeatedly irradiated with a pulsed laser, and mass spectrometry of the scattered material was performed by a time-of-flight mass spectrometer.

FIG. 7 shows the relationship between the signal intensity of the peak corresponding to the deuterium ion and the number of shots of the pulse laser. The horizontal axis represents the number of shots, and the vertical axis represents the signal intensity on an arbitrary scale. Solid lines a, b, and c in FIG. 7 indicate that the laser wavelength is 243.074 nm and 243.08, respectively.
The signal intensities at 0 nm and 243.060 nm are shown. The laser used was 1 energy per pulse.
It has a pulse width of 00 μJ and a pulse repetition frequency of 10 Hz.

When the object to be measured is irradiated with a laser, ablation occurs and a minute dent is formed on the surface. When the number of shots is increased, the depression becomes deeper. That is,
The number of shots can be considered to correspond to the depth of the measurement target.

When the laser wavelength is 243.074 nm or 2
In the case of 43.080 nm, the number of shots is 300 to
The signal strength is high in the region near 340 times. This indicates that a large amount of deuterium is distributed at a position corresponding to the depth of the depression formed by the irradiation of about 300 to 340 shots. in this way,
By measuring the signal intensity in association with the number of shots of the pulse laser, information on the concentration distribution of deuterium in the depth direction can be obtained.

When the laser wavelength is 243.060 nm, no peak corresponding to deuterium ions is observed, as expected from FIG.

In the above embodiment, the case where deuterium is detected has been described. However, tritium can be detected by the same method. At this time, D and T obtained from the reduced mass
The suitable laser wavelength for detecting T is predicted to be 243.050 to 243.060 nm from the relationship between the excitation wavelength of the laser beam and the suitable laser wavelength for detecting D.

In the above embodiment, the case of detecting deuterium in graphite has been described. However, it is possible to detect a specific atom in a solid by using a similar method. At this time, the wavelength of the laser that irradiates the measurement target is set as the excitation wavelength when the specific atom to be detected is in the scattered substance scattered by the ablation. This makes it possible to efficiently ionize the specific atom and detect the specific atom with high sensitivity using a time-of-flight mass spectrometer.

It should be noted that the excitation wavelength of a specific atom contained in the substance scattered by the ablation may be different from the excitation wavelength of the specific atom in the gas. By changing the wavelength of the laser near the excitation wavelength of the specific atom in the gas and measuring the signal intensity of the peak corresponding to the specific atom, it is possible to determine a suitable wavelength range when using ablation. . For example, when detecting Cu atoms, the laser wavelength is set to around 231.82 nm, and when detecting Fe atoms, the laser wavelength is set to 22.
When it is set to be around 3.83 nm and Al atoms are detected,
The laser wavelength is set to be around 228.15 nm.

Next, a detection apparatus according to an embodiment of the present invention will be described with reference to FIGS. In the detection device shown in FIG. 3, the laser is incident on the surface of the measuring object 5 almost perpendicularly. The surface of the measuring object 5 is substantially parallel to the direction of the extracted electric field. When a laser beam is incident on the measurement object 5, flying objects usually fly in a direction perpendicular to the surface of the measurement object 5. Therefore, the direction in which the flying objects fly out,
The direction of the extraction electric field is substantially orthogonal. For this reason, the efficiency with which the flying matter is taken into the time-of-flight mass spectrometer 20 is reduced.

In order to take the flying objects into the time-of-flight mass spectrometer 20 with high efficiency, it is preferable that the surface of the object 5 to be measured is arranged to face the time-of-flight mass spectrometer 20. However, with such an arrangement, the extraction electrode 2b and the time-of-flight mass spectrometer 20 become obstacles, so that the laser must be irradiated obliquely to the surface of the measurement object 5.

When the surface of the object 5 is irradiated with a laser obliquely, the object 5 is etched obliquely. For this reason, it is difficult to know the exact distribution of the atoms to be detected in the depth direction.

FIG. 1 is a schematic sectional view of an apparatus for detecting a specific atom according to an embodiment of the present invention. One end of the vacuum duct 40 is connected to the vacuum container 42. A quartz window 41 is attached to the other end of the vacuum container 40. A gas passage 44 for evacuation is attached to the side wall of the vacuum duct 40. An electrode 43 in which a sample is embedded is arranged in a vacuum container 42. The electrode 43 is arranged on an extension of the central axis of the vacuum duct 40, and holds the sample so that the sample surface is substantially perpendicular to the central axis of the vacuum duct. When the sample has conductivity, the sample itself may be used as the electrode 43.

In the vacuum duct 40, a convergence electrode 45, an extraction electrode 46, a diffusion electrode 47, and an electrostatic lens 48 are provided.
It is arranged along the central axis of the vacuum duct 40. The electrostatic lens 48 includes a plurality of electrodes 48A and 48B. Extraction electrode 46 and electrode 48 of electrostatic lens 48
A and 48B have a cylindrical shape, and are arranged along the central axis of the vacuum duct 40 so that the respective central axes coincide with the central axis of the vacuum duct 40. The extraction electrode 46 is arranged at a position closest to the electrode 43. The electrodes 48A and 48B are alternately arranged along the central axis.

The convergence electrode 45 and the diffusion electrode 47 have a disk-like shape having an opening at the center. These electrodes are all arranged such that their respective central axes coincide with the central axis of the vacuum duct 40.

The convergence electrode 45 is centered on an extraction electrode 46.
Has a disc-like shape provided with a through hole larger than the outer periphery of the vacuum duct 40, and is arranged such that the central axis thereof coincides with the central axis of the vacuum duct 40. The position of the convergence electrode 45 in the center axis direction substantially coincides with the end of the extraction electrode 46 on the electrode 43 side.

The diffusion electrode 47 is centered on the extraction electrode 46.
It has a disc-like shape provided with a through hole having substantially the same diameter as the inner circumference of the vacuum duct 40, and is arranged so that the central axis thereof coincides with the central axis of the vacuum duct 40. Further, the diffusion electrode 47 is disposed between the extraction electrode 46 and the electrostatic lens 48 in the central axis direction.

The DC power supply V1 is applied to the electrode 43 by, for example, +
A voltage of 0.5 kV is applied. The DC power supply V2 applies a voltage of, for example, +1 kV to the convergence electrode 45. The DC power supply V3 applies a voltage of, for example, −1 kV to the extraction electrode 46. The DC power supply V4 is connected to the electrode 48A of the electrostatic lens 48.
For example, a voltage of -1 kV is applied. Electrostatic lens 48
Electrode 48B is grounded.

The ion detector 35 is disposed between the electrostatic lens 48 and the end of the vacuum duct 40. The ion detector 35 includes, for example, the MCP 29, the anode 30, and the ammeter 31 illustrated in FIG.

A laser light source 36 causes a laser beam 37 to enter a vacuum duct 40 through a quartz window 41. The laser beam 37 that has entered the vacuum duct 40 passes beside the ion detector 35, and passes through each electrode 48 of the electrostatic lens 48.
A, 48B and the inside of the extraction electrode 46, and the electrode 43
To reach the sample held in. The sample is ablated by the laser, and a part of the sample is scattered.

Hereinafter, the operation of the detection apparatus shown in FIG. 1 will be described by taking as an example the case of detecting deuterium in a sample, as in the case described with reference to FIGS.

The deuterium in the flying object scattered from the sample is ionized by the laser beam 37. Deuterium ions and other ions are accelerated toward the vacuum duct 40 by an extraction electric field generated by the extraction electrode 46. Since the focusing electrode 45 concentrates the electric field generated from the electrode 43 on the extraction electrode 46, ions gather toward the central axis of the vacuum duct 40, and an ion beam that flies along the central axis is formed. The absolute value | V of the voltage applied to the focusing electrode 45 in order to obtain the ion beam focusing effect
2 | is preferably larger than the absolute value | V1 | of the voltage applied to the electrode 43.

The diffusion electrode 47 once diffuses the focused ion beam. The electrostatic lens 48 transports the ion beam to the ion detector 35 while repeating convergence and divergence. As in the case described with reference to FIGS. 4 to 7, the type of the arrived ion can be specified from the relationship between the ion detected by the ion detector 35 and the arrival time of the ion.

In the case of the embodiment shown in FIG.
The surface of the sample held at the surface faces the extraction electrode 46. Therefore, the particles scattered and ionized from the sample surface can be drawn into the extraction electrode 46 with high efficiency. This makes it possible to detect a trace amount of a specific atom with high sensitivity.

FIG. 2 is a perspective view of a moving mechanism of the detecting device according to the embodiment. The vacuum duct 40 and the laser light source 36 shown in FIG. further,
A vacuum pump 71 is fixed to the moving table 73. The vacuum pump 71 evacuates the vacuum duct 40. The moving table 73 is supported by the supporting table 74 so as to be movable in the horizontal direction. The moving mechanism 75 moves the moving table 73 in the horizontal direction.

A moving mechanism 77 is mounted on a rail 80 laid in the tokamak container. The moving mechanism 77
It can move along the rail 80. Moving mechanism 7
7, a support arm 76 is attached. The support arm 76 is vertically movable with respect to the moving mechanism 77. The support arm 76 holds the support table 74. By moving the support arm 76 in the vertical direction, the moving table 73 also moves in the vertical direction.

The vacuum duct 40 can be moved to a desired position by the moving mechanism 77, the support arm 76, and the moving mechanism 75. For example, the tip of the vacuum duct 40 is brought into close contact with the inner surface of the vacuum vessel of the nuclear reactor. For example, an O-ring is attached to the tip of the vacuum duct, and the tightness of the contact portion is maintained. After the inside of the vacuum duct 40 is evacuated to a predetermined degree of vacuum, the content of deuterium, tritium and the like on the inner surface of the vacuum vessel can be measured.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

[0061]

As described above, according to the present invention,
Scattered matter from the sample can be ionized and efficiently drawn into the ion transport path. This makes it possible to detect a specific atom in the sample with high sensitivity.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a detection device according to an embodiment.

FIG. 2 is a perspective view of a detection device and a driving device according to the embodiment.

FIG. 3 is a schematic diagram of a detection device according to a related invention.

FIG. 4 is a cross-sectional view schematically showing a time-of-flight mass spectrometer used in the detection device of the related invention.

FIG. 5A is a graph showing the signal intensity obtained by a time-of-flight mass spectrometer when the wavelength of the laser is optimized, and FIG. It is a graph showing the signal intensity by the time-of-flight mass spectrometer at the time of shifting.

FIG. 6 is a graph showing a relationship between a signal intensity of a peak corresponding to deuterium ions and a laser wavelength.

FIG. 7 is a graph showing the relationship between the signal intensity of a peak corresponding to deuterium ions and the number of shots of a pulse laser.

FIG. 8 is a cross-sectional view showing the flow of fuel around the core of the fusion reactor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 2a, 2b Extraction electrode 5 Object to be measured 10 Laser light source 11 Lens 13 Laser introduction window 20 Time-of-flight mass spectrometer 25 Acceleration electrode 26, 27 Slit 28 MCP 29 Deceleration electrode 30 Anode 31 Ammeter 35 Ion detector 36 Laser light source 40 Vacuum duct 41 Quartz window 42 Vacuum container 43 Electrode 44 Exhaust gas flow path 45 Focusing electrode 46 Extraction electrode 47 Diffusion electrode 48 Electrostatic lens 51 Vacuum container 52 Fuel injection device 53 Vacuum exhaust device 55 Superconducting coil 61 Divertor plate 63 Plasma

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuhisa Yokokawa 2-1-1 Tanidocho, Tanashi-shi, Tokyo Sumitomo Heavy Industries, Ltd. Tanashi Works (72) Inventor Hirofumi Nakamura 801 Mukaiyama, Nakamachi, Naka-gun, Ibaraki Prefecture Address: Nippon Atomic Energy Research Institute, Naka Research Institute (72) Inventor Toshihiko Yamanishi, Ibaraki Prefecture Naka-gun, Nakamachi, Oji 801 Address: Nippon Atomic Energy Research Institute, Naka Laboratory (72) Inventor: Masataka Nishi, 801 Mukaiyama, Nakamachi, Naka-machi, Naka-gun, Ibaraki Prefecture, Japan Atomic Energy Research Institute, Naka Research Institute

Claims (4)

[Claims] An extraction electrode for generating an extraction electric field in a space around an object to be measured, an ion transport path for transporting ions extracted by the extraction electrode, and an ion transported through the ion transport path. An ion detector, and a laser light source that, in the ion transport path, causes a laser beam to be incident so as to propagate in a direction opposite to the transport direction of ions, and reaches the measurement target to cause ablation. Atomic detector. 2. The method according to claim 2, wherein the ion transport path is arranged along a path along which the ions fly, and a plurality of cylindrical electrodes each surrounding the path of the ions, and an odd number of the plurality of cylindrical electrodes. Voltage applying means for setting a first potential and setting an even number to a second potential, wherein the laser light source is arranged so that the laser beam propagates inside the plurality of cylindrical electrodes. The specific atom detection device according to claim 1, wherein: 3. The method according to claim 2, wherein the laser light source has a wavelength of 243.070.
The specific atom detector according to claim 1 or 2, which emits a laser having a wavelength of ２４243.081 nm. 4. The laser light source has a wavelength of 243.050.
The specific atom detection device according to claim 1 or 2, which emits a laser having a wavelength of 243.060 nm.