JP2011106950A - Atom excitation layer forming method, atom excitation layer forming device, and magnetic field measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a positionally uniform and continuous effect for a long period of inhibiting relaxation of atomic spin of a medium sealed into a cell equipped in a measurement device using optical pumping. <P>SOLUTION: The atom excitation layer forming method forms an atom excitation layer, which covers a surface facing an internal space of a cell wall, by irradiating a cell having an internal space and equipped in the measurement device using optical pumping with a beam for forming an atom excitation layer and passing the beam for forming an atom excitation layer through the internal space along the surface facing the internal space of the cell wall. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an atomic excitation layer forming method, an atomic excitation layer forming apparatus, and a magnetic field measurement system.

  In a measurement device using optical pumping, when atoms of a medium enclosed in a cell collide with the inner wall surface of the cell, the atomic spin of the atoms of the medium is relaxed, resulting in a decrease in detection sensitivity of the measurement target. End up. Therefore, in Patent Document 1, for the purpose of suppressing the atomic spin of the atoms of the medium from being relaxed by forcibly returning the atomic spin of the medium colliding with the inner wall surface of the cell, the inner wall surface is disclosed. Describes the use of a cell coated with a non-magnetic material for an optical pumping magnetometer.

JP 2007-167616 A

  However, in the above technique, if the coating state is not uniform depending on the location, the effect of suppressing the relaxation of the atomic spin of the atoms in the medium cannot be obtained uniformly depending on the location. In addition, since the coating changes over time, the effect of suppressing the relaxation of the atomic spin of the atoms in the medium cannot be obtained continuously for a long time. Therefore, the present invention solves the above-mentioned problems, and maintains the effect of suppressing the relaxation of atomic spin of the medium enclosed in the internal space of the cell provided in the measuring device using optical pumping uniformly and for a long time. The present invention provides an atomic excitation layer forming method, an atomic excitation layer forming apparatus, and a magnetic field measurement system that can be obtained.

  In order to solve the above-described problem, the atomic excitation layer forming method according to the first aspect of the present invention is configured to irradiate a cell having an internal space provided in a measurement apparatus using optical pumping with an atomic excitation layer forming beam. The atomic excitation layer forming beam is allowed to pass through the internal space along the surface of the wall of the cell along the surface of the internal space. It is characterized by forming an atomic excitation layer that excites atoms of a medium enclosed in a space. According to such a configuration, a uniform atomic excitation layer can be formed over the entire region in the traveling direction of the beam for forming an atomic excitation layer on the surface of the cell wall on the inner space side. Therefore, the effect of suppressing the relaxation of the atomic spins of the atoms of the medium enclosed in the internal space of the cell can be obtained over the entire traveling direction of the beam for forming the atomic excitation layer. In addition, to form an atomic excitation layer with little secular change without applying a physical coating with much aging, the atomic spin relaxation of the atoms in the medium is suppressed by continuing to irradiate the beam for forming the atomic excitation layer. This effect can be obtained continuously for a long time.

  In the atomic excitation layer forming method, the end surface of the internal space may be irradiated with the atomic excitation layer forming beam having a surface shape including the end surface of the internal space on the end surface of the internal space. According to such a configuration, a uniform atomic excitation layer can be formed over the entire area in the circumferential direction of the cell wall on the surface of the cell wall on the inner space side. Therefore, the effect of suppressing the relaxation of the atomic spins of the atoms of the medium enclosed in the internal space of the cell can be obtained over the entire circumferential direction of the wall of the cell.

  In the atomic excitation layer forming method, the optical pumping beam irradiation device provided in the measurement device may irradiate the cell with the atomic excitation layer forming beam having the same wavelength as the optical pumping beam irradiated on the cell. Good. According to such a configuration, atoms of the medium colliding with the cell wall can be excited by the generated atomic excitation layer and the atomic spin can be forcibly restored. Further, since the components can be shared by the irradiation source of the atomic excitation layer forming beam and the irradiation source of the optical pumping beam, the cost of the irradiation source of the atomic excitation layer forming beam can be reduced. .

  In addition, the atomic excitation layer forming apparatus according to the second aspect of the present invention irradiates a cell having an internal space provided in a measuring apparatus using optical pumping with an atomic excitation layer forming beam, thereby By passing the atomic excitation layer forming beam through the internal space along the surface of the internal space side of the part, the surface of the cell wall is sealed in the internal space on the surface of the internal space side. It is characterized by forming an atomic excitation layer for exciting atoms of a medium. According to such a configuration, a uniform atomic excitation layer can be formed over the entire region in the traveling direction of the beam for forming an atomic excitation layer on the surface of the cell wall on the inner space side. Therefore, the effect of suppressing the relaxation of the atomic spins of the atoms of the medium enclosed in the internal space of the cell can be obtained over the entire traveling direction of the beam for forming the atomic excitation layer. In addition, to form an atomic excitation layer with little secular change without applying a physical coating with much aging, the atomic spin relaxation of the atoms in the medium is suppressed by continuing to irradiate the beam for forming the atomic excitation layer. This effect can be obtained continuously for a long time.

  Further, the magnetic field measurement system of the third aspect of the present invention irradiates a measurement device using optical pumping and a cell having an internal space provided in the measurement device with an atomic excitation layer forming beam, By passing the atomic excitation layer forming beam through the internal space along the surface of the cell wall portion on the internal space side, the surface of the cell wall portion on the internal space side is transferred to the internal space. And an atomic excitation layer forming device for forming an atomic excitation layer for exciting atoms of the enclosed medium. According to such a configuration, the effect of suppressing the relaxation of atomic spins of the atoms of the medium enclosed in the internal space of the cell can be obtained continuously for a long period of time. The measurement object can be measured.

  In the magnetic field measurement system, the measurement device may include a plurality of the cells, and the magnetic field measurement system may include the atomic excitation layer forming device for each of the plurality of cells. According to such a configuration, for each of the plurality of cells included in the measurement apparatus, the atomic excitation layer is uniform over the entire region in the traveling direction of the beam for forming the atomic excitation layer on the surface on the inner space side of the cell wall. Can be formed. Therefore, for each of the plurality of cells included in the measurement apparatus, the effect of suppressing the relaxation of atomic spins of the atoms of the medium enclosed in the internal space of the cell is exerted over the entire traveling direction of the beam for forming the atomic excitation layer. Can be obtained. Also, in order to form an atomic excitation layer with little secular change without applying a physical coating with much secular change, each of a plurality of cells included in the measurement apparatus is continuously irradiated with an atomic excitation layer forming beam. Thus, the effect of suppressing the relaxation of the atomic spin of the atoms of the medium can be continuously obtained for each of the plurality of cells included in the measuring apparatus.

  In the magnetic field measurement system, the measurement device includes a plurality of the cells, and the magnetic field measurement system uses the atomic excitation layer forming beam output from the atomic excitation layer formation device as a plurality of the atomic excitation layers. Branching into a forming beam, irradiating each of the plurality of cells with the beam for forming an atomic excitation layer, along the surface of the wall portion of the cell on the inner space side, and into the inner space You may further provide the optical splitter which lets the beam for atomic excitation layer formation pass. According to such a configuration, for each of the plurality of cells included in the measurement apparatus, the atomic excitation layer is uniform over the entire region in the traveling direction of the beam for forming the atomic excitation layer on the surface on the inner space side of the wall portion of the cell. Can be formed. Therefore, for each of the plurality of cells included in the measurement apparatus, the effect of suppressing the relaxation of atomic spins of the atoms of the medium enclosed in the internal space of the cell is exerted over the entire traveling direction of the beam for forming the atomic excitation layer. Can be obtained. Also, in order to form an atomic excitation layer with little secular change without applying a physical coating with much secular change, each of a plurality of cells included in the measurement apparatus is continuously irradiated with an atomic excitation layer forming beam. Thus, the effect of suppressing the relaxation of the atomic spin of the atoms of the medium can be continuously obtained for each of the plurality of cells included in the measuring apparatus. In particular, the atomic excitation layer forming beam output from the atomic excitation layer forming apparatus is branched into a plurality of atomic excitation layer forming beams and irradiated to a plurality of cells. Variation of the beam profile can be easily suppressed. In addition, when changing the profile of the atomic excitation layer forming beam irradiated to a plurality of cells, it is only necessary to change the profile of the atomic excitation layer forming beam output from the atomic excitation layer forming apparatus. The profile of the irradiated atomic excitation layer forming beam can be easily changed.

1 shows a configuration of a magnetic field measurement system 10 according to a first embodiment. The cross section of the cell 210 in the state in which the atomic excitation layer was formed is shown. The cross section of the cell 210 in the state in which the atomic excitation layer was formed is shown. The structure of the magnetic field measurement system 10 which concerns on 2nd Example is shown. The structure of the magnetic field measurement system 10 which concerns on 3rd Example is shown.

<First embodiment>
FIG. 1 shows a configuration of a magnetic field measurement system 10 according to the first embodiment. The magnetic field measurement system 10 measures a magnetic field at a measurement position to be measured. For example, the magnetic field measurement system 10 is used in a biological measurement system that measures a very weak magnetic field of several fT (femtotesla) or less, such as a magnetoencephalograph or a magnetocardiograph. The magnetic field measurement system 10 includes an optical pumping magnetometer 200 which is a measurement device using optical pumping. The optical pumping magnetometer 200 includes a cell 210, a probe light irradiation device 220, an optical pumping beam irradiation device 230, and a detection device 240.

  The cell 210 has a cylindrical shape having an internal space. In the example shown in FIG. 1, the cell 210 has a cylindrical shape. The internal space of the cell 210 is filled with cesium gas, which is one of alkali metal gases, as an example of a medium.

  The optical pumping beam irradiation device 230 irradiates the cell 210 with the optical pumping beam 230A. Specifically, the optical pumping beam irradiation device 230 uses circularly polarized light having a wavelength suitable for optical pumping of a medium enclosed in the internal space of the cell 210 as an optical pumping beam 230A in the x-axis direction (the central axis of the cell 210). The cell 210 is irradiated from the (direction) to pass through the internal space of the cell 210. As a result, the atoms of the medium enclosed in the internal space of the cell 210 are excited, and the directions of the electron spins are aligned.

  The probe light irradiation device 220 irradiates the cell 210 with the probe light 220A. Specifically, the probe light irradiation device 220 uses the linearly polarized light as the probe light 220A in the y-axis direction (x) in a state where the electron spin directions of the atoms of the medium enclosed in the internal space of the cell 210 are aligned. The cell 210 is irradiated from a direction (perpendicular to the axial direction) to pass through the internal space of the cell 210. The plane of polarization of the probe light 220A that has passed through the internal space of the cell 210 is rotated according to the strength of the magnetic field at the measurement position of the measurement target.

  The detection device 240 detects the intensity of the magnetic field at the measurement position of the measurement target from the probe light 220 </ b> A emitted from the cell 210. For example, the detection device 240 transmits polarized light having a specific rotation angle from the probe light 220 </ b> A emitted from the cell 210 by the polarizing plate. And the detection apparatus 240 detects the intensity | strength of the polarized light which permeate | transmitted the polarizing plate with a photodiode. Furthermore, the detection device 240 calculates the polarization rotation angle of the probe light 220 </ b> A emitted from the cell 210 based on the detected polarization intensity and rotation angle. In addition, the detection device 240 calculates the strength of the magnetic field at the measurement position of the measurement target based on the detected polarization rotation angle.

  The magnetic field measurement system 10 of this embodiment further includes an atomic excitation layer forming apparatus 100. The atomic excitation layer forming apparatus 100 irradiates the cell 210 with the atomic excitation layer forming beam 100A, so that the wall of the cell 210 (the wall of the cell 210 extending in the x-axis direction) By passing the atomic excitation layer forming beam 100A through the internal space of the wall portion of the cell 210 along the surface on the internal space side (hereinafter referred to as “inner wall surface”), the inner surface of the cell 210 An atomic excitation layer that excites atoms of the medium enclosed in the internal space is formed. Specifically, the atomic excitation layer forming apparatus 100 irradiates the end surface of the internal space of the cell 210 with the atomic excitation layer forming beam 100A having the same wavelength as that of the optical pumping beam 230A from the x-axis direction. The atomic excitation layer forming beam 100A is allowed to pass through the internal space of the cell 210 along the inner wall surface. As a result, the atomic excitation layer forming apparatus 100 is an atomic excitation layer that covers the inner wall surface of the cell 210, and the atomic excitation layer that excites the atoms of the medium enclosed in the cell 210 is replaced with atoms on the inner wall surface of the cell 210. The excitation layer forming beam 100A is uniformly formed over the entire traveling direction.

  In the atomic excitation layer forming apparatus 100, the atomic excitation layer forming beam 100 </ b> A having a surface shape including the end surface of the internal space of the cell 210 is applied to the end surface of the internal space of the cell 210. By irradiating, a uniform atomic excitation layer is formed on the inner wall surface of the cell 210 over the entire circumferential direction of the wall portion of the cell 210. For example, the atomic excitation layer forming apparatus 100 transmits an atomic excitation layer forming beam 100A having the same surface shape as the end surface of the internal space of the cell 210 to the end surface of the internal space of the cell 210. Irradiate the end face. In the example shown in FIG. 1, since the end face of the internal space of the cell 210 has a circular shape, the atomic excitation layer forming apparatus 100 uses a beam for forming an atomic excitation layer that has a circular shape on the end face of the internal space of the cell 210. 100A is irradiated to the end surface of the internal space of the cell 210. In this way, the atomic excitation layer forming apparatus 100 efficiently forms an atomic excitation layer that is uniform and has little secular change over the entire inner wall surface of the cell 210.

  By covering the inner wall surface of the cell 210 with the atomic excitation layer, the atoms of the medium that collided with the wall portion of the cell 210 are excited by the atomic excitation layer in front of the wall portion of the cell 210, and the atomic spin is forced. Will be restored. Since the atomic excitation layer forming apparatus 100 forms an atomic excitation layer that is uniform and has little secular change on the inner wall surface of the cell 210 without applying a physical coating that is nonuniform and has many secular changes, The effect of suppressing the relaxation of the atomic spin can be obtained uniformly and continuously for a long time.

  FIG. 2 shows a cross section of the wall of the cell 210 in a state where the atomic excitation layer is formed. FIG. 2 shows a cross section when the wall portion of the cell 210 in a state where the atomic excitation layer is formed is viewed from the x-axis direction that is the traveling direction of the atomic excitation layer forming beam 100A. The atomic excitation layer forming apparatus 100 irradiates the end surface of the internal space of the cell 210 with the atomic excitation layer forming beam 100 </ b> A over the entire circumferential direction of the inner wall surface of the cell 210. Thereby, as shown in FIG. 2, the atomic excitation layer 210 </ b> A covering the inner wall surface of the cell 210 is formed on the inner wall surface of the cell 210 over the entire area in the circumferential direction of the inner wall surface of the cell 210.

  FIG. 3 shows a cross section of the wall portion of the cell 210 in a state where the atomic excitation layer is formed. FIG. 3 shows a cross section when the wall portion of the cell 210 in a state where the atomic excitation layer is formed is viewed from a direction orthogonal to the traveling direction of the atomic excitation layer forming beam 100A. The atomic excitation layer forming apparatus 100 transmits an atomic excitation layer forming beam 100A that satisfies the condition of passing through the internal space of the cell 210 along the inner wall surface of the cell 210 from the x-axis direction with respect to the end surface of the internal space of the cell 210. Irradiate. For example, the atomic excitation layer forming apparatus 100 irradiates the end surface of the internal space of the cell 210 with an atomic excitation layer forming beam 100A that satisfies the following conditions (1) and (2) from the x-axis direction. (1) It has the same surface shape as the end face (cross section) of the internal space of the cell 210. (2) The axial direction and the traveling direction of the internal space of the cell 210 are parallel.

  The atomic excitation layer forming beam 100 </ b> A irradiated from the atomic excitation layer forming apparatus 100 passes through the internal space of the cell 210 in the x-axis direction along the inner wall surface of the cell 210. As a result, as shown in FIG. 3, the atomic excitation layer 210 </ b> A covering the inner wall surface of the cell 210 is formed on the inner wall surface of the cell 210 over the entire region in the x-axis direction (advancing direction of the atomic excitation layer forming beam 100 </ b> A). Is formed.

<Second embodiment>
FIG. 4 shows a configuration of the magnetic field measurement system 10 according to the second embodiment. In the magnetic field measurement system 10 illustrated in FIG. 4, a plurality of rectangular tube-shaped cells 210 are provided in the irradiation direction (y-axis direction) of the probe light 220 </ b> A, and optical pumping beam irradiation is performed on each of the plurality of cells 210. 1 differs from the magnetic field measurement system 10 shown in FIG. 1 in that an apparatus 230 and an atomic excitation layer forming apparatus 100 are provided. Each of the plurality of atomic excitation layer forming apparatuses 100 operates in the same manner as the atomic excitation layer forming apparatus 100 described in the first embodiment. That is, each of the plurality of atomic excitation layer forming apparatuses 100 forms an atomic excitation layer on the inner wall surface of the corresponding cell 210 by irradiating the corresponding cell 210 with the atomic excitation layer forming beam 100A.

  According to the magnetic field measurement system 10 according to the second embodiment, for each of the plurality of cells 210, on the inner wall surface of the cell 210, the entire region in the circumferential direction of the inner wall surface of the cell 210, and the atomic excitation layer forming beam 100A. A uniform atomic excitation layer can be formed over the entire region in the traveling direction. Therefore, for each of the plurality of cells 210, the effect of suppressing the relaxation of the atomic spins of the atoms of the medium enclosed in the internal space of the cell is the effect of forming an atomic excitation layer throughout the circumferential direction of the inner wall surface of the cell 210. It can be obtained over the entire region in the traveling direction of the beam 100A. Further, an atomic excitation layer with little secular change is formed on each of the plurality of cells 210 without applying physical coating with much secular change. Therefore, by continuously irradiating each of the plurality of cells 210 with the atomic excitation layer forming beam 100A, the effect of suppressing the relaxation of the atomic spin of the atoms in the medium can be continuously obtained for a long period of time. .

  In the magnetic field measurement system 10 according to the second embodiment, a plurality of cells 210 are provided in the uniaxial (y-axis) direction, but a plurality of cells 210 may be provided in the biaxial direction. For example, a plurality of cells 210 may be provided side by side in a lattice shape when viewed from the x-axis direction. Also in these cases, a plurality of atomic excitation layer forming apparatuses 100 and a plurality of optical pumping beam irradiation apparatuses 230 are provided corresponding to the positions of the plurality of cells 210, and the first implementation is performed on each of the plurality of cells 210. By irradiating the atomic excitation layer forming beam 100A under the same conditions as the atomic excitation layer forming beam 100A irradiated by the atomic excitation layer forming apparatus 100 described in the example, atomic excitation is applied to each inner wall surface of the plurality of cells 210. A layer can be formed.

<Third embodiment>
FIG. 5 shows a configuration of the magnetic field measurement system 10 according to the third embodiment. The magnetic field measurement system 10 shown in FIG. 5 includes the single atomic excitation layer forming device 100 and the optical splitter 510 instead of the plurality of atomic excitation layer forming devices 100, and the magnetic field measurement system 10 shown in FIG. And different. The optical splitter 510 branches the atomic excitation layer forming beam 100A output from the atomic excitation layer forming apparatus 100 into a plurality of atomic excitation layer forming beams 100A. Specifically, the optical splitter 510 uses the atomic excitation layer forming beam 100A incident from the entrance provided corresponding to the position of the atomic excitation layer forming apparatus 100 to form the atomic excitation layer for the number of cells 210. Branch to the beam 100A. Each of the plurality of atomic excitation layer forming beams 100 </ b> A is emitted from the exit provided corresponding to the position of the corresponding cell 210, and is irradiated to the corresponding cell 210.

  The optical splitter 510 sets a condition for passing through the internal space of the cell 210 along the inner wall surface of the cell 210 for each of the plurality of cells 210 as in the atomic excitation layer forming apparatus 100 described in the first embodiment. An atomic excitation layer forming beam 100 </ b> A to be filled is irradiated to the end face of the internal space of the cell 210 from the x axis direction. That is, the optical splitter 510 is configured so that the atomic excitation layer forming beam having the same conditions as the atomic excitation layer forming beam 100A irradiated by the atomic excitation layer forming apparatus 100 described in the first embodiment to each of the plurality of cells 210. By irradiating with 100 A, an atomic excitation layer is formed on each inner wall surface of the plurality of cells 210.

  According to the magnetic field measurement system 10 according to the third embodiment, for each of the plurality of cells 210, the inner wall surface of the cell 210, the entire region in the circumferential direction of the inner wall surface of the cell 210, and the atomic excitation layer forming beam 100A. A uniform atomic excitation layer can be formed over the entire region in the traveling direction. Therefore, for each of the plurality of cells 210, the effect of suppressing the relaxation of the atomic spins of the atoms of the medium enclosed in the internal space of the cell is the effect of forming an atomic excitation layer throughout the circumferential direction of the inner wall surface of the cell 210. It can be obtained over the entire region in the traveling direction of the beam 100A. Further, an atomic excitation layer with little secular change is formed on each of the plurality of cells 210 without applying physical coating with much secular change. Therefore, by continuously irradiating each of the plurality of cells 210 with the atomic excitation layer forming beam 100A, the effect of suppressing the relaxation of the atomic spin of the atoms in the medium can be continuously obtained for a long period of time. .

  In particular, according to the magnetic field measurement system 10 according to the third embodiment, the atomic excitation layer forming beam 100A output from one atomic excitation layer forming apparatus 100 is branched into a plurality of atomic excitation layer forming beams 100A. Since irradiation is performed on the plurality of cells 210, variation in the profile of the atomic excitation layer forming beam 100A irradiated on the plurality of cells 210 can be easily suppressed. Further, when changing the profile of the atomic excitation layer forming beam 100A irradiated to the plurality of cells 210, the profile of the atomic excitation layer forming beam 100A output from the atomic excitation layer forming apparatus 100 may be changed. The profile of the atomic excitation layer forming beam 100A irradiated to the plurality of cells 210 can be easily changed.

  The magnetic field measurement system 10 shown in FIG. 5 is also provided with one optical pumping beam irradiation device 230 and an optical splitter 520 instead of the plurality of optical pumping beam irradiation devices 230. And different. The optical splitter 520 branches the optical pumping beam 230A output from the optical pumping beam irradiation device 230 into a plurality of optical pumping beams 230A. Specifically, the optical splitter 520 branches the optical pumping beam 230A incident from the entrance provided corresponding to the position of the optical pumping beam irradiation device 230 into optical pumping beams 230A corresponding to the number of cells 210. . Each of the plurality of optical pumping beams 230 </ b> A is emitted from the exit provided corresponding to the position of the corresponding cell 210, and is irradiated to the corresponding cell 210.

  According to the magnetic field measurement system 10 according to the third embodiment, the optical pumping beam 230A output from one optical pumping beam irradiation device 230 is branched into a plurality of optical pumping beams 230A and irradiated to a plurality of cells 210. The variation in the profile of the optical pumping beam 230A applied to the plurality of cells 210 can be easily suppressed. Further, when changing the profile of the optical pumping beam 230A irradiated to the plurality of cells 210, the profile of the optical pumping beam 230A output from the optical pumping beam irradiation device 230 may be changed. It is possible to easily change the profile of the optical pumping beam 230A.

  In the magnetic field measurement system 10 according to the third embodiment, a plurality of cells 210 are provided in the uniaxial (y-axis) direction, but a plurality of cells 210 may be provided in the biaxial direction. For example, a plurality of cells 210 may be provided side by side in a lattice shape when viewed from the x-axis direction. Also in these cases, an optical splitter 510 for irradiating a plurality of atomic excitation layer forming beams 100A and an optical splitter 520 for irradiating a plurality of optical pumping beams 230A are provided corresponding to the positions of the plurality of cells 210. By irradiating each of the plurality of cells 210 with the atomic excitation layer forming beam 100A under the same conditions as the atomic excitation layer forming beam 100A irradiated by the atomic excitation layer forming apparatus 100 described in the first embodiment, An atomic excitation layer can be formed on the inner wall surface of each of the plurality of cells 210.

  The magnetic field measurement system 10 according to the third embodiment includes a plurality of atomic excitation layer forming devices 100 and optical splitters 510, and a plurality of atomic excitation layer forming devices 100 and optical splitters 510 are used for each of the plurality of cells 210. The atomic excitation layer forming beam 100A may be irradiated. Further, a plurality of optical pumping beam irradiation devices 230 and optical splitters 520 may be provided, and the optical pumping beams 230A may be irradiated to each of the plurality of cells 210 by the plurality of optical pumping beam irradiation devices 230 and the optical splitter 520. .

  The magnetic field measurement system 10 of the present embodiment is not limited to the configuration described in the first to third examples. For example, the atomic excitation layer forming apparatus 100 and the optical pumping beam irradiation apparatus 230 may be provided to face each other with the cell 210 interposed therebetween as shown in FIG. 4, and as shown in FIG. It may be provided in one direction. The magnetic field measurement system 10 is not limited to a biological measurement system as long as it is a system that measures a magnetic field, and may be used for other systems. Further, if the atomic excitation layer forming apparatus 100 is circularly polarized light having a wavelength suitable for optical pumping of the medium enclosed in the cell 210, the atomic excitation layer forming beam 100A having the same wavelength as the optical pumping beam 230A is used. May be irradiated to the cell 210, or the atomic excitation layer forming beam 100A having a wavelength different from the wavelength of the optical pumping beam 230A may be irradiated to the cell 210.

  Further, the atomic excitation layer forming apparatus 100 may have an adjusting mechanism that can adjust the width of the atomic excitation layer by adjusting the width of the atomic excitation layer forming beam 100A. Thereby, for example, the user can easily adjust the width of the atomic excitation layer so that the optical pumping sensor sensitivity is the highest.

  In addition, the cell 210 is not limited to a cylindrical shape and a rectangular tube shape, and any cell can be used as long as the atomic excitation layer forming beam 100A can be passed through the inner space of the cell 210 along the inner wall surface of the cell 210. You may have shapes other than. In addition, the atomic excitation layer forming apparatus 100 may have an adjustment mechanism that can adjust the surface shape of the atomic excitation layer forming beam 100A in accordance with the shape of the end face of the internal space of the cell 210. The medium enclosed in the cell 210 is not limited to cesium gas, and other alkali metal gases such as potassium gas and rubidium gas may be used. Further, the medium enclosed in the cell 210 is not limited to the alkali metal gas, and other mediums such as a rare gas may be used. Further, the atomic excitation layer forming apparatus 100 may have an adjustment mechanism capable of adjusting the wavelength of the atomic excitation layer forming beam 100A in accordance with the medium enclosed in the cell 210.

  DESCRIPTION OF SYMBOLS 10 ... Magnetic field measurement system, 100 ... Atomic excitation layer formation apparatus, 100A ... Atomic excitation layer formation beam, 200 ... Optical pumping magnetometer, 210 ... Cell, 210A ... Atomic excitation layer, 220 ... Probe light irradiation apparatus, 220A ... Probe Light, 230 ... Optical pumping beam irradiation device, 230A ... Optical pumping beam, 240 ... Detection device, 510 ... Optical splitter, 520 ... Optical splitter

Claims (7)

A cell having an internal space provided in a measuring apparatus using optical pumping is irradiated with an atomic excitation layer forming beam, and the internal space is then moved along the surface of the wall portion of the cell to the internal space. An atomic excitation layer for exciting atoms of a medium enclosed in the internal space is formed on a surface of the cell wall portion on the internal space side by passing an atomic excitation layer forming beam. A method for forming an atomic excitation layer. 2. The atom according to claim 1, wherein the end surface of the internal space is irradiated with the beam for forming an atomic excitation layer having a surface shape including the end surface of the internal space at an end surface of the internal space. Excitation layer forming method. The optical pumping beam irradiation apparatus provided in the measurement apparatus irradiates the cell with the beam for forming an atomic excitation layer having the same wavelength as that of the optical pumping beam applied to the cell. A method for forming an atomic excitation layer as described in 1. above. A cell having an internal space provided in a measuring apparatus using optical pumping is irradiated with an atomic excitation layer forming beam, and the internal space is then moved along the surface of the wall portion of the cell to the internal space. An atomic excitation layer for exciting atoms of a medium enclosed in the internal space is formed on a surface of the cell wall portion on the internal space side by passing an atomic excitation layer forming beam. An atomic excitation layer forming apparatus. A measuring device using optical pumping;
Irradiating an atomic excitation layer forming beam to a cell having an internal space provided in the measurement apparatus, and forming the atomic excitation layer in the internal space along the surface of the cell wall on the internal space side And an atomic excitation layer forming device that forms an atomic excitation layer that excites atoms of the medium enclosed in the internal space on the surface of the wall of the cell on the internal space side by passing the beam for use. Magnetic field measurement system characterized by this. The measuring device is
Having a plurality of said cells;
The magnetic field measurement system
The magnetic field measurement system according to claim 5, wherein the atomic excitation layer forming device is provided for each of the plurality of cells. The measuring device is
Having a plurality of said cells;
The magnetic field measurement system
The atomic excitation layer forming beam output from the atomic excitation layer forming apparatus is branched into a plurality of atomic excitation layer forming beams, and the atomic excitation layer forming beam is supplied to each of the plurality of cells. The optical splitter according to claim 5, further comprising an optical splitter that irradiates and passes the atomic excitation layer forming beam through the internal space along a surface of the wall portion of the cell on the internal space side. Magnetic field measurement system.

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