JP2017125690A - Magnetic measurement device manufacturing method and gas cell manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic measurement device manufacturing method and a gas cell manufacturing method with which it is possible to suppress a decrease in manufacturing yield and an increase in manufacturing man-hours and improve productivity.SOLUTION: A manufacturing method for a magnetic measurement device 100 for measuring a magnetic field includes: a storing step of inserting an ampule 20 from an opening 18 into a reservoir 16 of a cell part 12 having a main chamber 14, the reservoir 16 communicating with the main chamber 14 and having a longitudinal direction and an opening 18 provided at an opposite side to the main chamber 14 in the longitudinal direction of the reservoir 16, and storing the ampule 20 therein; a sealing step of sealing the opening 18 with a sealing part 19; and an irradiation step of irradiating a pulsed laser beam 40 to the ampule 20. In the storing step, an adhesive compound 25 is arranged on at least one of an inner wall of the reservoir 16 and the ampule 20.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a method for manufacturing a magnetic measuring device and a method for manufacturing a gas cell.

  2. Description of the Related Art An optically-pumped magnetic measuring device that irradiates a gas cell filled with an alkali metal gas with linearly polarized light and measures a magnetic field according to a rotation angle of a polarization plane is known. In Patent Document 1, an ampoule in which an alkali metal is sealed is stored in a reservoir (ampoule housing chamber), and a laser beam is irradiated to the ampoule to form a through hole in the ampoule glass tube. A gas cell manufacturing method is disclosed in which the main chamber is filled with vapor (gas) from a reservoir through a communication hole by evaporation.

JP 2012-183290 A

  By the way, for example, when the ampule is inserted from the opening provided in the reservoir and stored in the reservoir, and the opening is sealed with the sealing portion, the handling from the step of storing the ampule to the step of sealing is handled. When sealing with the sealing part, the ampoule may come out of the reservoir from the opening. Also, when irradiating the ampoule with laser light, the ampoule position varies from individual to individual and deviates from the laser light irradiation position, or the ampoule moves due to the impact of laser light irradiation because the ampoule is not stable in the reservoir. If this happens, there is a possibility that alkali metal gas cannot be generated without processing in the depth direction by laser light irradiation. If these occur, the manufacturing yield will decrease and the number of manufacturing steps will increase due to reworking.

  As a member for generating the alkali metal gas, a form other than the ampoule described in Patent Document 1 is also conceivable. Accordingly, an object of the present invention is to prevent a member for generating an alkali metal gas such as an ampoule housed in the reservoir from going out of the opening and hold the laser in a stable state in the reservoir. An object of the present invention is to provide a method for manufacturing a magnetic measuring device and a method for manufacturing a gas cell, which can reliably generate an alkali metal gas by light irradiation, and can improve productivity by suppressing a decrease in manufacturing yield and an increase in manufacturing man-hours.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A method for manufacturing a magnetic measurement device according to this application example is a method for manufacturing a magnetic measurement device that measures a magnetic field, and includes a first chamber and a second chamber that communicates with the first chamber and has a longitudinal direction. A solid material containing an alkali metal is inserted into the second chamber of the cell portion having a chamber and an opening provided on the opposite side of the first chamber in the longitudinal direction of the second chamber from the opening. Storage step, a sealing step of sealing the opening with a sealing portion, and an irradiation step of irradiating the solid material with laser light. In the storage step, the second chamber A chain saturated hydrocarbon is disposed on at least one of the inner wall and the solid matter.

  According to the manufacturing method of this application example, in the storing step, when inserting and storing a solid material containing alkali metal that is a member for generating alkali metal gas from the opening in the second chamber of the cell unit, A chain saturated hydrocarbon is disposed on at least one of the inner wall of the second chamber and the solid. Therefore, solid matter can be fixed to the inner wall of the second chamber due to the stickiness of the chain saturated hydrocarbon, so when sealing the opening with the sealing part in the handling and sealing process from the storage process to the sealing process. The solid material can be prevented from going out of the second chamber through the opening. When the solid material is irradiated with laser light in the irradiation process to generate an alkali metal gas, the solid material is displaced from the irradiation position of the laser light or the solid material moves due to the impact of the laser light irradiation. Therefore, alkali metal gas can be generated more reliably. As a result, it is possible to provide a method of manufacturing a magnetic measuring device that can suppress a decrease in manufacturing yield and an increase in manufacturing man-hours and improve productivity.

  [Application Example 2] A method of manufacturing a magnetic measurement device according to the application example, wherein in the sealing step, the cell portion is arranged such that the longitudinal direction is along the vertical direction and the opening is on the lower side in the vertical direction. It is preferable to arrange on the sealing part.

  According to the manufacturing method of this application example, since the cell portion is arranged on the sealing portion so that the opening portion is on the lower side in the vertical direction in the sealing step, for example, the low melting point glass is sealed as a sealing material. When fixing the stopper and the cell part, the load should be applied to the cell part located above while heating the low melting point glass from the sealing part side located below, and the sealing is performed efficiently. Can do. At that time, since the solid matter is fixed to the inner wall of the second chamber via the chain saturated hydrocarbon, even if the cell portion is arranged so that the longitudinal direction is along the vertical direction and the opening is on the lower side. The solid material can be prevented from going out of the second chamber through the opening.

  [Application Example 3] A method of manufacturing a magnetic measuring device according to the application example, wherein the solid is an ampoule filled with an alkali metal, and in the irradiation step, a pulse having a wavelength in an ultraviolet region is applied to the ampoule. It is preferable to irradiate with laser light.

  According to the manufacturing method of this application example, in the irradiation step, the ampule filled with alkali metal is irradiated with pulsed laser light having a wavelength in the ultraviolet region, so that the ampule glass tube is not damaged without damaging the cell portion. A through-hole can be formed and the alkali metal inside can be evaporated to generate an alkali metal gas. Also, when irradiating pulsed laser light, the ampoule is fixed to the inner wall of the second chamber via a chain saturated hydrocarbon, so the ampoule may be displaced from the irradiation position of the pulsed laser light, or irradiated with pulsed laser light. It is possible to prevent the ampoule from moving due to the shock caused by.

  Application Example 4 In the method of manufacturing a magnetic measurement device according to the application example, the solid matter is a pill containing an alkali metal compound and an adsorbent, and in the irradiation step, the pill has a red to infrared region. It is preferable to irradiate a continuous wave laser beam having a wavelength.

  According to the manufacturing method of this application example, in the irradiation step, the pill containing the alkali metal compound and the adsorbent is irradiated with a continuous wave laser beam having a wavelength in the red to infrared region. The compound is activated to generate an alkali metal gas, and impurities generated at that time can be adsorbed by the adsorbent. In addition, when irradiating continuous wave laser light, the pill is fixed to the inner wall of the second chamber via a chain saturated hydrocarbon. It is possible to prevent the pill from moving due to the impact of laser light irradiation.

  Application Example 5 A gas cell manufacturing method according to this application example includes a first chamber, a second chamber communicating with the first chamber and having a longitudinal direction, and the first chamber in the longitudinal direction of the second chamber. A storage step of inserting and storing a solid material containing an alkali metal from the opening into the second chamber of the cell portion having an opening provided on the opposite side of the opening, and sealing the opening with the sealing portion A sealing step of sealing, and an irradiation step of irradiating the solid with a laser beam. In the storing step, a chain saturated hydrocarbon is disposed on at least one of the inner wall of the second chamber and the solid. It is characterized by doing.

  According to the manufacturing method of this application example, in the storing step, when inserting and storing a solid material containing alkali metal that is a member for generating alkali metal gas from the opening in the second chamber of the cell unit, A chain saturated hydrocarbon is disposed on at least one of the inner wall of the second chamber and the solid. Therefore, since solids can be fixed to the inner wall of the second chamber via the chain saturated hydrocarbon, when sealing the opening with the sealing part in the handling and sealing process from the storage process to the sealing process, It can suppress that a solid substance comes out of a 2nd chamber from an opening part. When the solid material is irradiated with laser light in the irradiation process to generate an alkali metal gas, the solid material is displaced from the irradiation position of the laser light or the solid material moves due to the impact of the laser light irradiation. Therefore, alkali metal gas can be generated more reliably. As a result, it is possible to provide a method of manufacturing a gas cell that can suppress a decrease in manufacturing yield and an increase in manufacturing man-hours and can improve productivity.

  Application Example 6 In the gas cell manufacturing method according to the application example described above, in the sealing step, the cell portion is configured such that the longitudinal direction is along the vertical direction and the opening is on the lower side in the vertical direction. It is preferable to arrange on the sealing part.

  According to the manufacturing method of this application example, since the cell portion is arranged on the sealing portion so that the opening portion is on the lower side in the vertical direction in the sealing step, for example, the low melting point glass is sealed as a sealing material. When fixing the stopper and the cell part, the load should be applied to the cell part located above while heating the low melting point glass from the sealing part side located below, and the sealing is performed efficiently. Can do. At that time, since the solid matter is fixed to the inner wall of the second chamber via the chain saturated hydrocarbon, even if the cell portion is arranged so that the longitudinal direction is along the vertical direction and the opening is on the lower side. The solid material can be prevented from going out of the second chamber through the opening.

  Application Example 7 In the gas cell manufacturing method according to the application example, the solid material is an ampoule filled with an alkali metal, and in the irradiation step, the ampule has a pulse laser beam having a wavelength in an ultraviolet region. Is preferably irradiated.

  According to the manufacturing method of this application example, in the irradiation step, the ampule filled with alkali metal is irradiated with pulsed laser light having a wavelength in the ultraviolet region, so that the ampule glass tube is not damaged without damaging the cell portion. A through-hole can be formed and the alkali metal inside can be evaporated to generate an alkali metal gas. Also, when irradiating pulsed laser light, the ampoule is fixed to the inner wall of the second chamber via a chain saturated hydrocarbon, so the ampoule may be displaced from the irradiation position of the pulsed laser light, or irradiated with pulsed laser light. It is possible to prevent the ampoule from moving due to the shock caused by.

  Application Example 8 In the gas cell manufacturing method according to the application example, the solid matter is a pill containing an alkali metal compound and an adsorbent, and in the irradiation step, the pill has a wavelength in a red to infrared region. Irradiation with continuous wave laser light is preferred.

  According to the manufacturing method of this application example, in the irradiation step, the pill containing the alkali metal compound and the adsorbent is irradiated with a continuous wave laser beam having a wavelength in the red to infrared region. The compound is activated to generate an alkali metal gas, and impurities generated at that time can be adsorbed by the adsorbent. In addition, when irradiating continuous wave laser light, the pill is fixed to the inner wall of the second chamber via a chain saturated hydrocarbon. It is possible to prevent the pill from moving due to the impact of laser light irradiation.

The block diagram which shows the structure of the magnetic measuring device which concerns on this embodiment. Sectional drawing along the longitudinal direction of the gas cell which concerns on 1st Embodiment. FIG. 2B is a cross-sectional view taken along line A-A ′ of FIG. 2A. Sectional drawing along the longitudinal direction of the ampoule which concerns on 1st Embodiment. FIG. 3B is a cross-sectional view taken along line B-B ′ of FIG. 3A. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 1st Embodiment. The perspective view of the pill which concerns on 2nd Embodiment. Sectional drawing along the longitudinal direction of the gas cell which concerns on 2nd Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 2nd Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 2nd Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 2nd Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on 2nd Embodiment. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. The figure explaining the manufacturing method of the gas cell which concerns on the modification 1. As shown in FIG. FIG. 6 is a schematic diagram illustrating a configuration of an atomic oscillator according to a second modification. The figure explaining operation | movement of the atomic oscillator which concerns on the modification 2. FIG. The figure explaining operation | movement of the atomic oscillator which concerns on the modification 2. FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. The drawings to be used are appropriately enlarged, reduced or exaggerated so that the part to be described can be recognized. In addition, illustrations of components other than those necessary for the description may be omitted.

(First embodiment)
<Configuration of magnetic measuring device>
The configuration of the magnetic measurement apparatus according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the magnetic measurement apparatus according to this embodiment. The magnetic measurement apparatus 100 according to the present embodiment is a magnetic measurement apparatus that uses non-linear optical rotation (NMOR). The magnetic measurement apparatus 100 is a biological state measurement apparatus (such as a magnetocardiograph or a magnetoencephalograph) that measures a minute magnetic field generated from a living body such as a magnetic field from the heart (magnetomagnetic field) or a magnetic field from the brain (magnetomagnetic field). Used for. The magnetic measuring device 100 can also be used for a metal detector or the like.

  As shown in FIG. 1, the magnetic measurement device 100 includes a light source 1, an optical fiber 2, a connector 3, a polarizing plate 4, a gas cell 10, a polarization separator 5, and a photodetector (Photo Detector: PD) 6. And a light detector 7, a signal processing circuit 8, and a display device 9. In the gas cell 10, an alkali metal gas (a gas-state alkali metal atom) is sealed. As the alkali metal, for example, cesium (Cs), rubidium (Rb), potassium (K), sodium (Na), or the like can be used. Hereinafter, a case where cesium is used as the alkali metal will be described as an example.

  The light source 1 is a device that outputs a laser beam having a wavelength corresponding to the absorption line of cesium (for example, 894 nm corresponding to the D1 line), for example, a tunable laser. The laser beam output from the light source 1 is so-called CW (Continuous Wave) light having a constant light amount continuously.

  The polarizing plate 4 is an element that polarizes the laser beam in a specific direction to make it linearly polarized light. The optical fiber 2 is a member that guides the laser beam output from the light source 1 to the gas cell 10 side. For the optical fiber 2, for example, a single mode optical fiber that propagates only the fundamental mode is used. The connector 3 is a member for connecting the optical fiber 2 to the polarizing plate 4. The connector 3 is a screw-in type and connects the optical fiber 2 to the polarizing plate 4.

  The gas cell 10 is a box (cell) having a gap inside, and an alkali metal vapor (alkali metal gas 13 shown in FIG. 2A) is sealed in the gap (main chamber 14 shown in FIG. 2A). The configuration of the gas cell 10 will be described later.

  The polarization separator 5 is an element that separates an incident laser beam into beams of two polarization components orthogonal to each other. The polarization separator 5 is, for example, a Wollaston prism or a polarization beam splitter. The photodetector 6 and the photodetector 7 are detectors sensitive to the wavelength of the laser beam, and output a current corresponding to the amount of incident light to the signal processing circuit 8. It is desirable that the photodetector 6 and the photodetector 7 are made of a non-magnetic material because they themselves may affect the measurement when a magnetic field is generated. The photodetector 6 and the photodetector 7 are disposed on the same side (downstream side) as the polarization separator 5 as viewed from the gas cell 10.

  The arrangement of each part in the magnetic measuring device 100 will be described along the laser beam path. The light source 1 is located at the uppermost stream of the laser beam path. Hereinafter, the optical fiber 2, the connector 3, and the polarizing plate 4 from the upstream side. The gas cell 10, the polarization separator 5, and the photodetectors 6 and 7 are arranged in this order.

  The laser beam output from the light source 1 is guided to the optical fiber 2 and reaches the polarizing plate 4. The laser beam reaching the polarizing plate 4 becomes linearly polarized light having a higher degree of polarization. The laser beam passing through the gas cell 10 excites (optically pumps) the alkali metal atoms sealed in the gas cell 10. At this time, the polarization plane of the laser beam is rotated by receiving the polarization plane rotation action corresponding to the strength of the magnetic field. The laser beam transmitted through the gas cell 10 is separated into two polarized component beams by the polarization separator 5. The light amounts of the two polarized component beams are measured (probing) by the photodetector 6 and the photodetector 7.

  The signal processing circuit 8 receives from each of the signals indicating the light amounts of the beams measured by the photodetector 6 and the photodetector 7. The signal processing circuit 8 measures the rotation angle of the polarization plane of the laser beam based on each received signal. The rotation angle of the polarization plane is expressed as a function based on the strength of the magnetic field in the propagation direction of the laser beam (for example, D. Budker, et al., “Resonant nonlinear magneto-optical rotation effect of atoms”, Review of See Equation (2) in Modern Physics, USA, American Physical Society, October 2002, Vol. 74, No. 4, p.1153-11201, although Equation (2) relates to linear optical rotation. In the case of NMOR, almost the same formula can be used). The signal processing circuit 8 measures the strength of the magnetic field in the propagation direction of the laser beam from the rotation angle of the polarization plane. The display device 9 displays the strength of the magnetic field measured by the signal processing circuit 8.

  Next, the configuration of the gas cell according to the first embodiment and the ampule used in the gas cell will be described with reference to FIGS. 2A, 2B, 3A, and 3B.

<Configuration of gas cell>
FIG. 2A is a sectional view along the longitudinal direction of the gas cell according to the first embodiment. 2B is a cross-sectional view taken along line AA ′ of FIG. 2A.

  2A and 2B, the height direction of the gas cell 10 is taken as the Z axis, and the upper side is taken as the + Z direction. A direction intersecting the Z axis, the longitudinal direction of the gas cell 10 is taken as the X axis, and the right side in FIG. 2A is taken as the + X direction. And it is a direction which cross | intersects a Z-axis and an X-axis, Comprising: Let the width direction of the gas cell 10 be a Y-axis, and let the right side in the paper surface of FIG. 2B be a + Y direction.

  As shown in FIG. 2A, the gas cell 10 according to the first embodiment includes a cell part 12 and a sealing part 19. The cell portion 12 is a box (cell) having a gap inside, and is formed of, for example, quartz glass. The thickness of the cell portion 12 is 1 mm to 5 mm, for example, about 1.5 mm.

  The cell unit 12 includes a main chamber 14 serving as a first chamber and a reservoir 16 serving as a second chamber whose longitudinal direction is the X-axis direction as internal voids. The main chamber 14 and the reservoir 16 are filled with a gas 13 in which alkali metal has evaporated (hereinafter referred to as alkali metal gas). In addition to the alkali metal gas 13, an inert gas such as a rare gas may be present in the main chamber 14 and the reservoir 16.

  The main chamber 14 and the reservoir 16 are arranged so as to be aligned along the X-axis direction, which is the longitudinal direction, and communicate with each other via the communication hole 15. The communication hole 15 is provided on the upper side (+ Z direction side) of the main chamber 14 and the reservoir 16. An opening 18 is provided on the opposite side (−X direction side) of the main chamber 14 and the communication hole 15 in the longitudinal direction of the reservoir 16.

  The opening 18 is sealed by a sealing part 19, and the cell part 12 (the main chamber 14 and the reservoir 16) is thereby sealed. For example, quartz glass is used as the material of the sealing portion 19. The sealing portion 19 is fixed to the cell portion 12 via, for example, a low melting point glass frit (not shown) disposed around the opening 18.

  An ampoule 20 is accommodated in the reservoir 16. A through hole (opening) 21 is formed in the glass tube 22 of the ampoule 20. The alkali metal gas 13 is obtained by evaporating (gasifying) the alkali metal solid 24 (see FIG. 3A) filled in the ampule 20. The configuration of the ampule 20 will be described later.

An adhesive 25 is disposed between the ampoule 20 and the inner wall of the reservoir 16. The ampoule 20 is fixed to the inner wall of the reservoir 16 via an adhesive 25. The adhesive 25 is composed of chain saturated hydrocarbons such as paraffin. As an example of paraffin, for example, pentacontane represented by a chemical formula (CH ₃ (CH ₂ ) ₄₈ CH ₃ ) can be used.

  The chain saturated hydrocarbon such as paraffin has an adhesive property that can fix the ampoule 20 to the inner wall of the reservoir 16 and also has an effect of increasing the non-relaxation characteristics of the inner wall of the cell portion 12 (the main chamber 14 and the reservoir 16). It is suitable as a material for the adhesive 25. Therefore, the adhesive 25 may be disposed on the inner wall of the reservoir 16 where the ampule 20 is not fixed, or a thin film of the adhesive 25 is formed on the inner wall of the cell portion 12 (the main chamber 14 and the reservoir 16). May be.

  2A is a line passing through the through hole 21 formed in the ampoule 20 (glass tube 22) along the Z axis intersecting the longitudinal direction of the gas cell 10, and FIG. It is a YZ cross section of the gas cell 10 in FIG. As shown in FIG. 2B, the opening 18 has, for example, a circular shape. The inner diameter of the opening 18 is, for example, about 0.4 mm to 1.5 mm. Although not shown, the communication hole 15 has a circular shape, for example. The inner diameter of the communication hole 15 is, for example, about 0.4 mm to 1 mm. The sealing part 19 has a rectangular shape, for example, but may have another shape such as a circular shape.

<Configuration of ampoule>
FIG. 3A is a cross-sectional view along the longitudinal direction of the ampoule according to the first embodiment. 3B is a cross-sectional view taken along line BB ′ of FIG. 3A. As shown to FIG. 3A, the ampoule 20 as a solid substance containing the alkali metal which concerns on 1st Embodiment has a longitudinal direction. FIG. 3A shows an XZ cross section when the ampoule 20 is arranged so that the longitudinal direction thereof is along the X-axis direction. The ampoule 20 is composed of a hollow glass tube 22. The glass tube 22 is made of, for example, borosilicate glass.

  The glass tube 22 extends along one direction (X-axis direction in FIG. 3A), and both ends thereof are welded. Thereby, the hollow glass tube 22 is sealed. In addition, the shape of the both ends of the glass tube 22 is not limited to a round shape as shown to FIG. 3A, The shape close | similar to a plane, the shape where one part sharpened, etc. may be sufficient. The hollow interior of the glass tube 22 is filled with an alkali metal solid (granular or powdery alkali metal atoms) 24. As the alkali metal solid 24, as described above, rubidium, potassium, and sodium can be used in addition to cesium.

  FIG. 3A shows a state where the ampoule 20 (glass tube 22) is sealed. At the stage where the ampule 20 is manufactured, the glass tube 22 is in a sealed state, but when the gas cell 10 is completed, a through hole 21 (see FIG. 2A) is formed in the glass tube 22 and the sealing is broken. Thereby, the alkali metal solid 24 in the ampoule 20 evaporates and flows out into the gas cell 10, and the gap of the cell portion 12 is filled with the alkali metal gas 13 (see FIG. 2A). In addition, a gap of about 1.5 mm is provided in the + Z direction, for example, between the upper surface of the ampoule 20 and the inner surface of the cell part 12 so that the alkali metal solid 24 can easily evaporate and flow out from the ampoule 20. (See FIG. 2A).

  FIG. 3B shows a YZ cross section in a direction intersecting the longitudinal direction of the ampoule 20. As shown in FIG. 3B, the shape of the glass tube 22 in the YZ section is, for example, a substantially circular shape, but may be another shape. The outer diameter φ of the glass tube 22 is 0.2 mm ≦ φ ≦ 1.2 mm. The thickness t of the glass tube 22 is 0.1 mm ≦ t ≦ 0.5 mm, and is preferably about 20% of the outer diameter φ. When the thickness t of the glass tube 22 is less than 0.1 mm, the glass tube 22 is likely to be damaged, and when the thickness t of the glass tube 22 exceeds 0.5 mm, the through hole 21 is formed in the glass tube 22. (Details will be described later).

<Gas cell manufacturing method>
Next, a method for manufacturing a gas cell according to the first embodiment will be described with reference to FIGS. 4A, 4B, 5A, 5B, 6A, and 6B. FIG. 4A, FIG. 4B, FIG. 5A, FIG. 5B, FIG. 6A, and FIG. 6B are views for explaining a gas cell manufacturing method according to the first embodiment. 4A, 4B, 5A, 5B, and 6B are cross-sectional views corresponding to FIG. 2A, and FIG. 6A is a cross-sectional view corresponding to FIG. 2B. The manufacturing method of the gas cell which concerns on this embodiment includes a storage process, a sealing process, and an irradiation process.

  First, the cell unit 12 shown in FIG. 4A is prepared. Although illustration is omitted, for example, a glass plate made of quartz glass is cut to prepare glass plate members corresponding to the respective wall surfaces constituting the cell portion 12. Then, these glass plate members are assembled, and the glass plate members are joined together by an adhesive or welding to obtain a cell portion 12 having a main chamber 14 and a reservoir 16 as shown in FIG. 4A. At this stage, the opening 18 of the cell portion 12 is opened.

  Subsequently, as shown in FIG. 4B, the ampule 20 is stored in the reservoir 16 of the cell portion 12 (storage step). As shown by an arrow in FIG. 4B, the ampule 20 is inserted into the reservoir 16 along the longitudinal direction (X-axis direction) from the opening 18 provided in the reservoir 16 of the cell portion 12. The ampule 20 is inserted into the reservoir 16 so that the extending direction thereof is along the longitudinal direction (X-axis direction) of the reservoir 16.

  In the storing step, an adhesive 25 made of chain saturated hydrocarbon is disposed on at least one of the inner wall of the reservoir 16 and the surface of the ampoule 20. When the adhesive 25 is disposed on the inner wall of the reservoir 16, the adhesive 25 is disposed on a part of the inner wall of the reservoir 16 from the opening 18 using, for example, a needle or the like before the ampoule 20 is inserted. The position where the adhesive 25 is disposed is preferably the bottom of the reservoir 16 (−Z direction side), and more preferably the corner of the bottom.

  The ampoule 20 is inserted into the reservoir 16 through the opening 18, and the ampoule 20 is disposed at the position where the adhesive 25 on the inner wall is disposed. Thereby, the ampoule 20 is fixed to the inner wall of the reservoir 16 via the adhesive 25. The amount of the adhesive 25 disposed on the inner wall of the reservoir 16 takes into account the size and mass of the ampoule 20, and the ampoule 20 is subject to a change in posture in a sealing process, which will be described later, and an impact when laser light is irradiated in the irradiation process. The amount that does not move may be the minimum amount, and it may be larger than this minimum amount.

  When the adhesive 25 is disposed on the surface of the ampoule 20, the adhesive 25 is disposed on at least a part of the surface of the ampoule 20 using a needle or the like, and then the ampoule 20 is inserted into the reservoir 16 from the opening 18. . Then, the ampoule 20 is arranged in the reservoir 16 so that the adhesive 25 on the surface adheres to the inner wall of the reservoir 16. The adhesive 25 is disposed on the inner wall of the reservoir 16, and the ampoule 20 having the adhesive 25 disposed on the surface thereof is accommodated in the reservoir 16, so that both the inner wall of the reservoir 16 and the surface of the ampoule 20 are adhesive. 25 may be arranged.

  In the stage up to the storing step, the ampoule 20 is in a state where the hollow glass tube 22 is filled with an alkali metal solid 24 and sealed, as shown in FIG. 3A. The ampule 20 is filled with an alkali metal solid 24 in a hollow interior of a tubular glass tube 22 in a low pressure environment close to vacuum (ideally in a vacuum), and both ends of the glass tube 22 are welded and sealed. To form. Alkali metals such as cesium used as the alkali metal solid 24 are highly reactive and cannot be handled in the atmosphere. Therefore, they are stored in the cell portion 12 in a sealed state in the ampoule 20 under a low pressure environment.

  Subsequently, as shown in FIG. 5A, the opening 18 of the reservoir 16 is sealed with a sealing portion 19 (sealing step). In the sealing step, the cell portion 12 is sufficiently deaerated, and the cell portion 12 (the main chamber 14, the communication hole 15, and the reservoir 16) is sealed with a very small amount of impurities in the internal space. For example, a low melting point glass frit (not shown) is arranged around the opening 18 in at least one of the cell part 12 and the sealing part 19 in a low pressure environment close to a vacuum (ideally in a vacuum), and the cell part The cell part 12 is sealed by adhering 12 and the sealing part 19 to each other and sealing.

  When fixing the cell part 12 and the sealing part 19, as shown in FIG. 5A, the cell part 12 is set so that the longitudinal direction is along the vertical direction and the opening 18 is on the lower side in the vertical direction. It is preferable to arrange on the sealing part 19. With this arrangement, the cell portion 12 and the sealing portion 19 are applied with a load applied to the cell portion 12 located above while heating the low melting point glass frit from the sealing portion 19 side located below in the vertical direction. Can be efficiently sealed.

  Here, when the ampule 20 is not fixed to the inner wall of the reservoir 16 with the adhesive 25, when the cell portion 12 is arranged in the sealing step so that the opening 18 is on the lower side in the vertical direction, the ampule 20 is Since the longitudinal direction is arranged along the vertical direction, there is a possibility of going out of the reservoir 16 from the opening 18. In this embodiment, since the ampule 20 is fixed to the inner wall of the reservoir 16 with the adhesive 25, the ampule 20 is opened even if the cell portion 12 is arranged so that the opening 18 is on the lower side in the sealing process. It is possible to prevent the part 18 from going out of the reservoir 16.

  Subsequently, as shown in FIG. 5B and FIG. 6A, the pulsed laser light 40 is condensed by the condensing lens 42 and irradiated to the glass tube 22 of the ampoule 20 through the cell portion 12 (irradiation process). . The pulsed laser light 40 is irradiated so as to focus on the upper surface of the ampoule 20 (glass tube 22).

  As a result, as shown in FIG. 6B, a through hole 21 is formed in the glass tube 22, and the alkali metal solid 24 in the ampoule 20 evaporates and flows out into the gap of the gas cell 10. The alkali metal gas 13 flowing into the reservoir 16 flows into the main chamber 14 of the cell part 12 through the communication hole 15 and diffuses. As a result, as shown in FIG. 2A, the gap of the cell portion 12 is filled with the alkali metal gas 13. Since the laser beam is excellent in directivity and convergence, the through hole 21 can be easily formed in the glass tube 22 by irradiating the pulse laser beam 40.

  In the irradiation process, it is necessary to form the through hole 21 in the glass tube 22 of the ampoule 20 without damaging the cell portion 12. Therefore, when the cell portion 12 is formed of quartz glass and the glass tube 22 is formed of borosilicate glass, for example, pulse laser light 40 having a wavelength in the ultraviolet region is used. Light having a wavelength in the ultraviolet region passes through the quartz glass, but is slightly absorbed by the borosilicate glass. Accordingly, the through hole 21 can be formed by selectively processing the glass tube 22 of the ampoule 20 without damaging the cell portion 12.

  The energy of the pulse laser beam 40 is, for example, 20 μJ / pulse to 200 μJ / pulse. The pulse width of the pulse laser beam 40 is, for example, 10 nanoseconds to 50 nanoseconds, and preferably about 30 nanoseconds. The repetition frequency of the pulse laser beam 40 is, for example, about 50 kHz, and the irradiation time of the pulse laser beam 40 is, for example, about 100 msec.

  Further, in order to reliably form the through-hole 21 in the glass tube 22 of the ampoule 20 in the irradiation process, as shown in FIG. It is preferable to set so that it is located in the center part in the width direction (Y-axis direction) of the ampule 20. If the focal point of the pulse laser beam 40 is deviated from the central portion in the width direction of the ampoule 20, processing in the depth direction may not proceed and the glass tube 22 may not be able to penetrate.

  By the way, when the ampule 20 is not fixed to the inner wall of the reservoir 16 with the adhesive 25, the position of the ampule 20 varies depending on the individual in the reservoir 16, or a slight inclination or impact when the cell portion 12 is handled. The ampoule 20 may move and shift from the irradiation position of the pulse laser beam 40. If the ampoule 20 is not fixed, the ampoule 20 may move and deviate from the position due to the impact caused by the irradiation with the pulse laser beam 40. If it does so, the through-hole 21 cannot be formed in the glass tube 22 at an irradiation process, and the fall of the manufacturing yield in the process of manufacturing the gas cell 10 will result, and the increase in the manufacturing man-hour by reworking will be caused.

  In this embodiment, as shown in FIG. 5B and FIG. 6A, the ampule 20 is fixed to the inner wall of the reservoir 16 with the adhesive 25. Since it can suppress moving, the deviation | shift from the irradiation position of the pulse laser beam 40 of the ampule 20 is suppressed. And it can suppress that the ampule 20 moves by the impact by irradiation of the pulse laser beam 40 in an irradiation process. Thereby, since the through-hole 21 can be stably and reliably formed in the ampoule 20 and the alkali metal gas 13 can be generated, a decrease in the manufacturing yield of the gas cell 10 and an increase in manufacturing man-hours are suppressed, and productivity is improved. Can do.

  Here, if the YZ cross-sectional shape of the ampoule 20 is substantially circular, there is a possibility that the ampoule 20 may rotate and move due to the inclination or impact of the cell portion 12. As shown in FIG. 6A, when the ampoule 20 is arranged at the corner of the reservoir 16, the ampoule 20 is held in contact with two inner walls intersecting at the corner, so that the ampoule 20 can be held in a more stable state. Can be fixed.

  In the irradiation process, the alkali metal solid 24 only needs to evaporate and flow out from the ampoule 20, so that the invention is not limited to the formation of the through hole 21. For example, the glass tube 22 is cracked to divide the ampoule 20. Alternatively, the glass tube 22 may be broken.

  The method for manufacturing the magnetic measuring device 100 according to the present embodiment includes the method for manufacturing the gas cell 10 described above. The process of manufacturing the magnetic measurement device 100 according to the present embodiment can be omitted in the description since a known method can be used in processes other than the process of manufacturing the gas cell 10.

(Second Embodiment)
The second embodiment is different from the first embodiment in that the solid material containing an alkali metal is a pill instead of an ampule, but the configuration of the cell portion is substantially the same. The structure of the gas cell which concerns on 2nd Embodiment, and the pill used for a gas cell is demonstrated with reference to FIG. 7A and FIG. 7B. In addition, about the component which is common in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

<Pill configuration>
First, the structure of the pill as a solid substance containing an alkali metal according to the second embodiment will be described. FIG. 7A is a perspective view of a pill according to a second embodiment. As shown in FIG. 7A, the pill 30 according to the second embodiment has, for example, a substantially cylindrical shape. The cylindrical diameter φ of the pill 30 is, for example, about 1 mm, and the cylindrical height h of the pill 30 is, for example, about 1 mm. Note that the outer shape of the pill 30 is not limited to a substantially cylindrical shape, and may be another shape such as a rectangular parallelepiped or a sphere.

  The pill 30 includes an alkali metal compound and an adsorbent. When the pill 30 is irradiated with laser light in an irradiation process described later, the alkali metal compound is heated and activated to generate alkali metal, and impurities and impure gas released at that time are adsorbed by the adsorbent. As the alkali metal compound, when cesium is used as the alkali metal, for example, a cesium compound such as cesium molybdate or cesium chloride can be used. As the adsorbent, for example, zirconium powder, aluminum or the like can be used.

<Configuration of gas cell>
FIG. 7B is a cross-sectional view along the longitudinal direction of the gas cell according to the second embodiment. As shown in FIG. 7B, the gas cell 10A according to the second embodiment is similar to the gas cell 10 according to the first embodiment, and includes a cell portion 12 having a main chamber 14 and a reservoir 16 communicated with each other through a communication hole 15. Consists of.

  7B is completed, an alkali metal 26 (for example, cesium) is generated from the alkali metal compound of the pill 30 in the reservoir 16 and the main chamber 14 and the alkali metal gas 13 are evaporated from the alkali metal 26. Reservoir 16 is full. The adsorbent 31 that has adsorbed the impure gas, impurities, or the like may remain in the reservoir 16. Between the adsorbent 31 and the inner wall of the reservoir 16, an adhesive 25 made of chain saturated hydrocarbon is disposed.

<Gas cell manufacturing method>
Next, a method for manufacturing a gas cell according to the second embodiment will be described with reference to FIGS. 8A, 8B, 9A, and 9B. FIG. 8A, FIG. 8B, FIG. 9A, and FIG. 9B are views for explaining a gas cell manufacturing method according to the second embodiment. The gas cell manufacturing method according to the second embodiment is different from the gas cell manufacturing method according to the first embodiment in that the pill 30 is disposed in the reservoir 16 in the disposing step, and the continuous wave laser beam is irradiated in the irradiation step. However, the rest is almost the same. Note that description of the manufacturing method common to the first embodiment is omitted.

  As shown in FIG. 8A, the cell unit 12 is prepared, and the pill 30 is stored in the reservoir 16 of the cell unit 12 (storage process). Similar to the first embodiment, an adhesive 25 made of chain saturated hydrocarbon is disposed on at least one of the inner wall of the reservoir 16 and the pill 30. 8A, the pill 30 is inserted into the reservoir 16 from the opening 18 provided in the reservoir 16 of the cell portion 12 and fixed to the inner wall of the reservoir 16 via the adhesive 25.

  Subsequently, as shown in FIG. 8B, the opening 18 of the reservoir 16 is sealed with a sealing portion 19 in the same manner as in the first embodiment (sealing step). In the sealing process, since the pill 30 is fixed to the inner wall of the reservoir 16 with the adhesive 25, the pill 30 is opened from the opening 18 to the reservoir even if the cell portion 12 is arranged so that the opening 18 is on the lower side. 16 can be prevented from going outside.

  Subsequently, as shown in FIGS. 9A and 9B, the continuous wave laser beam 44 is condensed by the condenser lens 42 and irradiated to the pill 30 through the cell portion 12 (irradiation process). The continuous wave laser beam 44 is irradiated so as to be focused at a substantially central portion of the upper surface of the pill 30.

  As the continuous wave laser beam 44, for example, an LD (Laser Diode) laser that continuously oscillates in a wavelength from red to an infrared region (about 680 nm to 1200 nm) can be used. The wavelength of the continuous wave laser beam 44 is preferably about 800 nm. The output of the continuous wave laser beam 44 is, for example, about 1 W to 10 W, and preferably about 2 W to 5 W. The irradiation time of the continuous wave laser beam 44 is, for example, about 10 seconds to 5 minutes, and preferably about 30 seconds to 90 seconds.

  By irradiating the continuous wave laser beam 44, the pill 30 is heated, the alkali metal compound contained in the pill 30 is activated, and the alkali metal 26 is generated. Then, the alkali metal 26 evaporates to become the alkali metal gas 13, flows out into the reservoir 16, flows into the main chamber 14 of the cell portion 12 through the communication hole 15, and diffuses. As a result, as shown in FIG. 7B, the gap of the cell portion 12 is filled with the alkali metal gas 13. Impurities and impurity gases released from the alkali metal compound are adsorbed by the adsorbent 31.

  In the gas cell 10A according to the second embodiment, it is necessary to heat the pill 30 without damaging the cell portion 12. In the irradiation step according to the second embodiment, since the pill 30 is locally heated by irradiating the continuous wave laser beam 44, the entire reservoir 16 (cell unit 12) in which the pill 30 is stored is heated. Compared with, the influence of heat with respect to the member which comprises the cell part 12 can be suppressed.

  In order to locally heat the pill 30, it is preferable to set the irradiation position of the continuous wave laser beam 44 to the pill 30 so that the focal point of the continuous wave laser beam 44 is located at the center of the upper surface of the pill 30. . If the focus of the continuous wave laser beam 44 is deviated from the pill 30, the heating of the pill 30 is insufficient and the generation of alkali metal does not proceed, leading to a decrease in the manufacturing yield of the gas cell 10A and an increase in manufacturing man-hours due to reworking. It becomes.

  In this embodiment, as shown in FIGS. 9A and 9B, the pill 30 is fixed to the inner wall of the reservoir 16 with the adhesive 25, so that the position of the pill 30 varies in the reservoir 16 and the pill 30 is not handled in handling. Since it can suppress that it moves, the shift | offset | difference from the irradiation position of the continuous wave laser beam 44 of the pill 30 is suppressed. And it can suppress that the pill 30 moves by the impact by irradiation of the continuous wave laser beam 44 in an irradiation process. As a result, the alkali metal gas 13 can be generated by irradiating the pill 30 with the continuous wave laser beam 44 stably and surely to generate the alkali metal gas 13, thereby suppressing a decrease in manufacturing yield of the gas cell 10A and an increase in manufacturing man-hours. Can be improved.

  The above-described embodiments merely show one aspect of the present invention, and can be arbitrarily modified and applied within the scope of the present invention. As modifications, for example, the following can be considered.

(Modification 1)
In the magnetic measuring device and the gas cell manufacturing method of the above embodiment, the adhesive 25 is disposed on at least one part of the inner wall of the ampoule 20 and the reservoir 16 in order to fix the ampoule 20 to the inner wall of the reservoir 16 in the storing step. However, the present invention is not limited to such a method. The entire surface of the ampoule 20 or the entire inner wall of the reservoir 16 may be coated with the adhesive 25 (chain saturated hydrocarbon).

  10A, FIG. 10B, FIG. 10C, FIG. 11A, FIG. 11B, and FIG. 11C are views for explaining a method of manufacturing a gas cell according to the first modification. Specifically, FIGS. 10A, 10B, and 10C are diagrams for explaining the case where the adhesive 25 is coated on the entire surface of the ampoule 20, and FIGS. 11A, 11B, and 11C are attached to the entire inner wall of the reservoir 16. It is a figure explaining the case where the agent 25 is coated.

<When coating the entire surface of the ampoule>
As shown in FIG. 10A, an adhesive 25 (chain saturated hydrocarbon) is coated on the entire surface of the ampoule 20 in advance. Although illustration is omitted, for example, the ampoule 20 and the adhesive 25 are disposed in a sealed container, and the entire container is heated to about 200 ° C. Thereby, the thin film | membrane of the adhesive 25 is formed so that the whole surface of the ampoule 20 may be covered.

  As shown in FIG. 10B, when the ampoule 20 on which a thin film of the adhesive 25 is formed is stored in the reservoir 16, the ampoule 20 is fixed to the inner wall of the reservoir 16 via the adhesive 25. Since the entire surface of the ampoule 20 is covered with the adhesive 25, the ampoule 20 can be fixed to the inner wall of the reservoir 16 regardless of the position of the ampoule 20 in the reservoir 16.

  Since the entire surface of the ampoule 20 is covered with the adhesive 25, the ampoule 20 may be fixed at an undesirable position on the inner wall of the reservoir 16. For example, as shown in FIG. 10C, when the reservoir 16 is fixed to the inner wall on the upper side (+ Z direction side) of the reservoir 16, the distance between the upper surface of the reservoir 16 (the surface on the + Z direction side) and the surface of the ampoule 20 is reduced. Therefore, it becomes difficult to focus the pulse laser beam 40 on the surface of the ampoule 20 in the irradiation process.

  In such a case, as shown in FIG. 10C, when the portion where the ampule 20 on the upper surface of the reservoir 16 is fixed is locally heated with a heating device 45 (for example, a soldering iron), the adhesive 25 is melted. Since the ampule 20 is separated from the inner wall of the reservoir 16, the ampule 20 can be moved to another position in the reservoir 16. When the ampoule 20 is fixed to the inner wall on the bottom side (−Z direction side) of the reservoir 16, the distance between the upper surface of the reservoir 16 and the surface of the ampoule 20 is increased. It becomes easy to match the surface.

<When coating the entire inner wall of the reservoir>
As shown in FIG. 11A, the entire inner wall of the reservoir 16 is coated with an adhesive 25 (chain saturated hydrocarbon). Although illustration is omitted, for example, the adhesive 25 is disposed in a part of the reservoir 16, the opening 18 (see FIG. 4A) is temporarily sealed, the inside of the cell 12 is sealed, and the temperature is about 200 ° C. Bake for about a minute. Thereby, as shown in FIG. 11A, a thin film of the adhesive 25 is formed so as to cover the entire inner wall of the reservoir 16. When forming a thin film of the adhesive 25 on the inner wall of the reservoir 16, a thin film of the adhesive 25 may be formed on the inner wall of the main chamber 14.

  When the ampoule 20 is stored in the reservoir 16 in which the thin film of the adhesive 25 is formed on the entire inner wall, the ampoule 20 is fixed to the inner wall of the reservoir 16 via the adhesive 25. Since the entire inner wall of the reservoir 16 is covered with the adhesive 25, the ampoule 20 can be fixed to the inner wall of the reservoir 16 regardless of the position of the ampoule 20 in the reservoir 16.

  As shown in FIG. 11B, when the ampoule 20 is fixed to an unfavorable position (for example, the upper side) of the inner wall of the reservoir 16, the upper side (+ Z direction side) of the reservoir 16 is heated by the heating device 46. At the same time, the bottom side (+ Z direction side) of the reservoir 16 is cooled by the cooling device 48.

  Accordingly, as shown in FIG. 11C, the adhesive 25 on the upper side of the reservoir 16 is melted and concentrated on the bottom side, so that the ampoule 20 is moved away from the inner wall on the upper side of the reservoir 16 and moved to the bottom side of the reservoir 16. Can be fixed. Further, by concentrating the adhesive 25 to the bottom side of the reservoir 16, the thickness of the adhesive 25 on the bottom side is increased, so that the ampoule 20 can be more securely fixed to the inner wall of the reservoir 16.

  In the manufacturing method of Modification 1, the entire surface of the ampoule 20 may be coated with the adhesive 25 and the entire inner wall of the reservoir 16 may be coated with the adhesive 25. In addition, the method demonstrated in the modification 1 is applicable also when using the pill 30 of 2nd Embodiment.

(Modification 2)
An apparatus to which the gas cell according to the embodiment is applicable is not limited to the magnetic measurement apparatus 100. The gas cell according to the embodiment and the modification can be applied to, for example, an atomic oscillator such as an atomic clock. FIG. 12 is a schematic diagram illustrating a configuration of an atomic oscillator according to the second modification. 13A and 13B are diagrams illustrating the operation of the atomic oscillator according to the second modification.

  An atomic oscillator (quantum interference device) 101 according to the second modification illustrated in FIG. 13 is an atomic oscillator using a quantum interference effect. As shown in FIG. 12, the atomic oscillator 101 includes a gas cell 10 (or a gas cell 10A) according to the embodiment, a light source 71, optical components 72, 73, 74, and 75, a light detection unit 76, a heater 77, and the like. , A temperature sensor 78, a magnetic field generator 79, and a controller 80.

  The light source 71 emits two types of light (resonance light L1 and resonance light L2 shown in FIG. 13A) having different frequencies, which will be described later, as excitation light LL for exciting alkali metal atoms in the gas cell 10. The light source 71 is composed of, for example, a semiconductor laser such as a vertical cavity surface emitting laser (VCSEL). The optical components 72, 73, 74, and 75 are provided on the optical path of the excitation light LL between the light source 71 and the gas cell 10, respectively, and the optical component 72 (lens) and the optical component from the light source 71 side to the gas cell 10 side. 73 (polarizing plate), optical component 74 (darkening filter), and optical component 75 (λ / 4 wavelength plate) are arranged in this order.

  The light detection unit 76 detects the intensity of the excitation light LL (resonance light L1, L2) that has passed through the gas cell 10. The light detection part 76 is comprised, for example with the solar cell, the photodiode, etc., and is connected to the excitation light control part 82 of the control part 80 mentioned later. The heater 77 (heating unit) heats the gas cell 10 in order to maintain the alkali metal in the gas cell 10 in a gaseous state (as the alkali metal gas 13). The heater 77 (heating unit) is composed of, for example, a heating resistor.

  The temperature sensor 78 detects the temperature of the heater 77 or the gas cell 10 in order to control the amount of heat generated by the heater 77. The temperature sensor 78 includes various known temperature sensors such as a thermistor and a thermocouple. The magnetic field generator 79 generates a magnetic field that causes Zeeman splitting of a plurality of energy levels of the alkali metal in the gas cell 10 that are degenerated. Zeeman splitting can increase the resolution by widening the gap between different energy levels of alkali metal degeneration. As a result, the accuracy of the oscillation frequency of the atomic oscillator 101 can be increased. The magnetic field generator 79 is composed of, for example, a Helmholtz coil or a solenoid coil.

  The control unit 80 controls the excitation light control unit 82 that controls the frequency of the excitation light LL (resonant light L 1, L 2) emitted by the light source 71, and the temperature that controls the energization of the heater 77 based on the detection result of the temperature sensor 78. The controller 81 and the magnetic field controller 83 that controls the magnetic field generated from the magnetic field generator 79 to be constant. The control unit 80 is provided, for example, on an IC chip mounted on a substrate.

  The principle of the atomic oscillator 101 will be briefly described. FIG. 13A is a diagram for explaining the energy state of alkali metal in the gas cell 10 of the atomic oscillator 101, and FIG. 13B shows the frequency difference between the two lights from the light source 71 of the atomic oscillator 101 and the detection intensity at the light detector 76. It is a graph which shows the relationship. As shown in FIG. 13A, the alkali metal (alkali metal gas 13) enclosed in the gas cell 10 has a three-level energy level and has two ground states (bases) having different energy levels. There can be three states: a state S1, a ground state S2) and an excited state. Here, the ground state S1 is a lower energy state than the ground state S2.

  When such an alkali metal gas 13 is irradiated with two types of resonant lights L1 and L2 having different frequencies, according to the difference (ω1−ω2) between the frequency ω1 of the resonant light L1 and the frequency ω2 of the resonant light L2. The optical absorptance (light transmittance) of the resonance lights L1 and L2 in the alkali metal gas 13 changes. When the difference (ω1−ω2) between the frequency ω1 of the resonant light L1 and the frequency ω2 of the resonant light L2 matches the frequency corresponding to the energy difference between the ground state S1 and the ground state S2, the ground states S1 and S2 Each excitation to the excited state stops. At this time, the resonance lights L1 and L2 are transmitted without being absorbed by the alkali metal gas 13. Such a phenomenon is called a CPT phenomenon or an electromagnetically induced transparency (EIT) phenomenon.

  The light source 71 emits two types of light (resonant light L1 and resonant light L2) having different frequencies as described above toward the gas cell 10. Here, for example, when the frequency ω1 of the resonant light L1 is fixed and the frequency ω2 of the resonant light L2 is changed, the difference (ω1−ω2) between the frequency ω1 of the resonant light L1 and the frequency ω2 of the resonant light L2 is obtained. When the frequency ω0 corresponds to the energy difference between the ground state S1 and the ground state S2, the detection intensity of the light detection unit 76 increases sharply as shown in FIG. 13B. Such a steep signal is called an EIT signal. This EIT signal has an eigenvalue determined by the type of alkali metal. Therefore, by using such an EIT signal as a reference, a highly accurate atomic oscillator 101 can be realized.

  The gas cell 10 used for the atomic oscillator 101 is required to be small and have a long life. However, according to the configuration of the gas cell and the manufacturing method thereof according to the above embodiment, the gas cell 10 having a small size and a long life is provided. Since it can be stably manufactured, it can be suitably used for the atomic oscillator 101 having a small size, high accuracy, and long life.

  DESCRIPTION OF SYMBOLS 10,10A ... Gas cell, 12 ... Cell part, 13 ... Alkali metal gas (alkali metal gas), 14 ... Main chamber (first chamber), 16 ... Reservoir (second chamber), 18 ... Opening, 19 ... Sealing Stop part, 20 ... Ampoule (solid matter containing alkali metal), 25 ... Adhesive (chain saturated hydrocarbon), 30 ... Pill (solid matter containing alkali metal), 40 ... Pulse laser beam (laser beam), 44 ... continuous oscillation laser beam (laser beam), 100 ... magnetic measuring device.

Claims (8)

A method of manufacturing a magnetic measuring device for measuring a magnetic field,
A cell portion having a first chamber, a second chamber communicating with the first chamber and having a longitudinal direction, and an opening provided on the opposite side of the second chamber from the first chamber in the longitudinal direction. A storage step of inserting and storing a solid material containing an alkali metal into the second chamber from the opening;
A sealing step of sealing the opening with a sealing portion;
An irradiation step of irradiating the solid with a laser beam,
In the storing step, a chain saturated hydrocarbon is disposed on at least one of the inner wall of the second chamber and the solid material. It is a manufacturing method of the magnetic measuring device according to claim 1,
In the sealing step, the cell part is arranged on the sealing part so that the longitudinal direction is along the vertical direction and the opening is on the lower side in the vertical direction. Device manufacturing method. It is a manufacturing method of the magnetic measuring device according to claim 1 or 2,
The solid matter is an ampoule filled with alkali metal inside,
In the irradiation step, the ampoule is irradiated with pulsed laser light having a wavelength in the ultraviolet region. It is a manufacturing method of the magnetic measuring device according to claim 1 or 2,
The solid matter is a pill containing an alkali metal compound and an adsorbent,
In the irradiation step, the pill is irradiated with a continuous wave laser beam having a wavelength from red to an infrared region. A cell portion having a first chamber, a second chamber communicating with the first chamber and having a longitudinal direction, and an opening provided on the opposite side of the second chamber from the first chamber in the longitudinal direction. A storage step of inserting and storing a solid material containing an alkali metal into the second chamber from the opening;
A sealing step of sealing the opening with a sealing portion;
An irradiation step of irradiating the solid with a laser beam,
In the storing step, a chain saturated hydrocarbon is disposed on at least one of the inner wall of the second chamber and the solid material. It is a manufacturing method of the gas cell according to claim 5,
In the sealing step, the cell portion is disposed on the sealing portion so that the longitudinal direction is along the vertical direction and the opening is on the lower side in the vertical direction. Production method. It is a manufacturing method of the gas cell according to claim 5 or 6,
The solid matter is an ampoule filled with alkali metal inside,
In the irradiation step, the ampule is irradiated with pulsed laser light having a wavelength in the ultraviolet region. It is a manufacturing method of the gas cell according to claim 5 or 6,
The solid matter is a pill containing an alkali metal compound and an adsorbent,
In the irradiation step, the pill is irradiated with a continuous wave laser beam having a wavelength in a red to infrared region.

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