Sample cavity suitable for laser heating argon-argon dating analysis

Abstract

The utility model discloses a sample cavity suitable for laser heating argon-argon dating analysis. The sample cavity comprises a laser window, a sample pool, a gas release module for heating and releasing gas for the sample pool, a fixed plate and a lifting rod with a height adjusting function, the sample pool comprises a gas output pipeline and a sample cavity with a counter bore; the laser window comprises a base, a sealing ring, a pressure balance ring, a zinc sulfide glass sheet and a top plate, a lower through hole penetrating the upper and lower side surfaces of the base is formed in the middle of the base, and an upper through hole penetrating the upper and lower side surfaces of the top plate is formed in the top plate; the base is mounted on the sample cavity, and the lower through hole and the counter bore are opposite in position and are communicated together; the zinc sulfide glass sheet sleeves the lower through hole, the sealing ring sleeves the lower end of the zinc sulfide glass sheet, and the pressure balancing ring sleeves the upper end of the zinc sulfide glass sheet; and the sample cavity is connected with the fixed plate through a lifting rod. The device is smaller in size, convenient to use and suitable for different heights, and the micro-leakage risk after the sample pool is baked and the damage to the laser window in the baking process are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of geological sample analysis instruments, in particular to a sample cavity suitable for laser heating argon-argon dating analysis. Background Art

[0002] Laser step heating is one of the important gas extraction methods in argon-argon dating. This method uses a carbon dioxide laser to heat the sample and measures the relative content of argon isotopes released at different heating temperatures by mass spectrometry to obtain the argon-argon ages of each stage. The sample cavity is the place where the sample is stored, and the sample will be exposed to the atmosphere when it is replaced regularly; and generally has a relatively large volume compared to the increasingly compact purification system.

[0003] When argon-argon dating analysis is carried out using the static mass spectrometry method, the gas extraction system is completely isolated from the pumping system before the laser starts to heat the sample. The argon gas inherently adsorbed in the sample itself, in the cavity or in the pipeline will gradually be released into the vacuum cavity, becoming the main source of the system test background value. Especially after replacing the sample, it generally takes a long time for the system to be baked and evacuated to restore the system to the ultimate background value. Therefore, the background value of the sample cavity system will directly determine the background value of the entire test process. Secondly, when the gas content in the purification system is certain, the concentration of the element to be measured in the system is proportional to the volume of the entire vacuum system. Therefore, reducing the volume of the purification system as much as possible is one of the important means to improve the sensitivity of the entire system.

[0004] The laser sample cavity is one of the key components for realizing laser step heating argon-argon dating. After replacing the sample, baking is beneficial to improve the gas release rate of the sample and reduce the background value of the entire system. However, in order to achieve ultra-high vacuum, the entire sample cavity is tightly composed of various components with different thermal expansion coefficients, including zinc sulfide glass sheets, oxygen-free copper gaskets, stainless steel flanges and sealing rings, etc. During the heating and baking process, components with different thermal expansion coefficients have different responses, especially the zinc sulfide glass sheet. Too high temperature or too fast temperature change may affect the sealing performance of the entire sample cavity. Therefore, a sample cavity with high safety, convenient use and excellent performance is a necessary device for carrying out laser step heating argon-argon dating. Summary of the Utility Model

[0005] The purpose of the utility model is to overcome the above-mentioned deficiencies of the prior art and provide a sample cavity suitable for laser heating argon-argon dating analysis.

[0006] The present utility model is realized through the following technical solutions: A sample chamber applicable to laser heating argon-argon dating analysis, comprising a laser window, a sample cell, a degassing module for heating and degassing the sample cell, a fixing plate, and a lifting rod with a function of adjustable height; The sample cell includes a sample cavity and a gas output pipeline, the sample cavity is recessed from top to bottom to form a counterbore for placing a sample, and the gas output pipeline is communicated with the counterbore; The laser window includes a base, a sealing ring, a pressure balance ring, a zinc sulfide glass sheet, and a top plate, a lower through hole penetrating the upper and lower sides thereof is opened in the middle of the base, and an upper through hole penetrating the upper and lower sides thereof is opened in the top plate; The base is installed on the sample cavity, the lower through hole is opposite to and communicated with the counterbore in position, and a counterbore is formed by outward depression in the upper section of the lower through hole; The zinc sulfide glass sheet is sleeved at the counterbore of the lower through hole, the sealing ring is sleeved at the lower end of the zinc sulfide glass sheet, the pressure balance ring is sleeved at the upper end of the zinc sulfide glass sheet, the top plate is fixed to the base by screws, and the zinc sulfide glass sheet is located below the upper through hole; The lower part of the sample cavity is connected to the upper end of the lifting rod, and the lower end of the lifting rod is installed on the fixing plate; The degassing module wraps the outside of the sample cavity.

[0007] A washer made of oxygen-free copper is provided between the sample cavity and the base.

[0008] The degassing module includes a heating element, a thermocouple, a heat preservation box, and a temperature control unit; The heating element is a heating plate, a heating block, or a heating wire; The heat preservation box includes part or the whole of the sample cavity and is installed on the sample cavity by screws; The thermocouple is in contact with the sample cavity and monitors the temperature of the sample cavity in real time; The temperature control unit is connected to the heating element and controls its temperature, and the temperature control unit includes heating-up control, constant-temperature control, and cooling-down control.

[0009] The lifting rod includes a fixed rod, a screw rod, and a fixing nut; The upper end of the screw rod is connected to the lower part of the sample cavity, the lower end of the screw rod is sleeved inside the fixed rod and can slide along its inner wall, and the fixing nut is installed on the fixed rod and locks or loosens the screw rod by rotation; The lower end of the fixed rod is installed on the fixing plate.

[0010] The fixing plate is provided with a number of through holes distributed at equal intervals.

[0011] The diameter of the through hole is 6 mm, and the distance between adjacent through holes is 5-20 mm.

[0012] The diameter of the counterbore is 40 - 80 mm, and its depth is 8 - 20 mm; the inner diameter of the gas output pipeline is 6 - 18 mm, and its length is 10 - 50 mm; the diameter of the lower through hole is 30 - 70 mm, and the diameter of the countersunk head hole is 40 - 80 mm.

[0013] The sealing ring is a metal sealing ring.

[0014] The sealing ring is made of pure metal or alloy material with a Vickers hardness range of 8 - 60 HV.

[0015] The sealing ring is made of gold, silver, indium, tin, bismuth or Babbitt alloy.

[0016] Compared with the prior art, the advantages of the present utility model are as follows: In this device, zinc sulfide glass is sunk into the window bottom plate, and the window volume is as small as 9 cm 3 , which is much smaller than the current commercial window (80 cm 3 ). This design can not only reduce the laser travel distance but also greatly reduce the volume of the entire sample chamber; this device is designed with an adjustable lifting rod, which can be applicable to application scenarios with different heights; this device is designed with a fixed plate at the bottom, which can be applicable to installation environments with different hole sizes; this device is designed with a sample cell heat preservation box, which improves the temperature control ability of the sample cell. This device is designed with an accurate temperature control method, which can not only slowly raise and lower the temperature of the sample cell but also provide interlock protection when the temperature of the sample cell is abnormal, reducing the risk of micro-leakage after baking the sample cell and the damage of the laser window during the baking process. Description of the Drawings

[0017] Figure 1 is a perspective view of an embodiment of the present utility model;

[0018] Figure 2 is a front view of an embodiment of the present utility model;

[0019] Figure 3 is Figure 2 a cross-sectional view taken along the A - A direction in

[0020] Figure 4 is a perspective view of an embodiment of the present utility model longitudinally cut;

[0021] Figure 5 is a side view of an embodiment of the present utility model after removing the base and the heat preservation box;

[0022] Figure 6 is a perspective view of an embodiment of the present utility model after removing the base and the heat preservation box;

[0023] Figure 7 is a top view of the assembly of the top plate and the zinc sulfide window sheet of an embodiment of the present utility model;

[0024] Figure 8 is Figure 7 the sectional view taken along line B-B in the figure;

[0025] Figure 9 is the perspective view of the upper side direction after the top plate and the zinc sulfide window plate of the embodiment of the present utility model are assembled;

[0026] Figure 10 is the perspective view of the lower side direction after the top plate and the zinc sulfide window plate of the embodiment of the present utility model are assembled.

[0027] The meanings of the reference numerals in the figure are as follows: 1, top plate; 2, zinc sulfide window plate; 3, base; 4, sample cavity; 5, gas output pipeline; 6, screw; 7, heating element; 8, thermocouple; 9, heat preservation box; 10, fixing nut; 11, fixing rod; 12, fixing plate; 13, pressure balance ring; 14, sealing ring; 15, washer. Specific embodiments

[0028] The content of the present utility model will be further described in detail below with reference to the drawings and specific embodiments.

[0029] Embodiment

[0030] Refer to Figures 1 to 10 , which is a sample cavity applicable to laser heating argon-argon dating analysis, including a laser window, a sample cell, a degassing module for heating and degassing the sample cell, a fixing plate 12 and a lifting rod with a function of adjustable height; the sample cell includes a sample cavity 4 and a gas output pipeline 5, the sample cavity 4 is recessed from top to bottom to form a counterbore for placing a sample, and the gas output pipeline 5 is communicated with the counterbore; the laser window includes a base 3, a sealing ring 14, a pressure balance ring 13, a zinc sulfide glass sheet and a top plate 1, a lower through hole penetrating the upper and lower side surfaces thereof is opened in the middle of the base 3, and an upper through hole penetrating the upper and lower side surfaces thereof is opened in the top plate 1; the base 3 is installed on the sample cavity 4, the lower through hole and the counterbore are opposite in position and communicated with each other, and a counterbore is formed by the outer depression of the upper section of the lower through hole; the zinc sulfide glass sheet is sleeved at the counterbore of the lower through hole, the sealing ring 14 is sleeved at the lower end of the zinc sulfide glass sheet, the pressure balance ring 13 is sleeved at the upper end of the zinc sulfide glass sheet, the top plate 1 is fixed to the base 3 by screws, and the zinc sulfide glass sheet is located below the upper through hole; the lower part of the sample cavity 4 is connected to the upper end of the lifting rod, and the lower end of the lifting rod is installed on the fixing plate 12; the degassing module wraps the outside of the sample cavity 4.

[0031] A washer 15 made of oxygen-free copper CF63 material is arranged between the sample cavity 4 and the base 3.

[0032] The gas release module includes a heating element 7, a thermocouple 8, a heat preservation box 9 and a temperature control unit; the heating element 7 is a heating plate, a heating block or a heating wire; the heat preservation box 9 includes part or the whole of the sample cavity 4 and is installed on the sample cavity 4 by screws; the thermocouple 8 is in contact with the sample cavity 4 and monitors the temperature of the sample cavity 4 in real time; the temperature control unit is connected to the heating element 7 and controls its temperature. The temperature control unit includes heating-up control, constant-temperature control and cooling-down control. In this embodiment, the heat preservation material filled in the heat preservation box 9 is quartz wool; the sample cell is heated by a heating plate, and the thermocouple 8 (thermocouple) is used to measure the temperature.

[0033] The lifting rod includes a fixed rod 11, a screw rod 6 and a fixing nut 10; the upper end of the screw rod 6 is connected to the lower part of the sample cavity 4, the lower end of the screw rod 6 is sleeved in the fixed rod 11 and can slide along its inner wall, and the fixing nut 10 is installed on the fixed rod 11 and locks or loosens the screw rod 6 by rotation; the lower end of the fixed rod 11 is installed on the fixing plate 12. By adjusting the fixing nut 10 and the screw rod 6, the height of the lifting rod can be adjusted.

[0034] The fixing plate 12 is provided with a number of through holes evenly distributed. The whole device can be installed on the desktop through the through holes on the fixing plate 12 to fix the whole device.

[0035] The diameter of the through hole is 6 mm, and the distance between adjacent through holes is 5 - 20 mm.

[0036] The pressure balance ring 13 is a balance ring made of polytetrafluoroethylene material; the diameter of the counterbore is 40 - 80 mm, and its depth is 8 - 20 mm; the inner diameter of the gas output pipeline 5 is 6 - 18 mm, and its length is 10 - 50 mm; the diameter of the lower through hole is 30 - 70 mm, and the diameter of the countersunk head hole is 40 - 80 mm. The pressure balance ring 13 can also be made of pure metal material or alloy material, and its materials include but are not limited to iron, copper, aluminum, steel, etc.

[0037] The sealing ring 14 is a metal sealing ring 14.

[0038] The sealing ring 14 is made of pure metal or alloy material with a Vickers hardness range of 8 - 60 HV.

[0039] The sealing ring 14 is made of gold, silver, indium, tin, bismuth or Babbitt alloy.

[0040] In this embodiment, the lower through-hole is a through-hole with a diameter of 50 mm, and a counterbore with a diameter of 54 mm is formed at its upper end for the installation of the zinc sulfide glass sheet in the counterbore of the installation device. The sealing ring 14 is located on the lower side of the counterbore. By screwing to compress the sealing ring 14 between the base 3 and the top plate 1 and the zinc sulfide glass sheet, the base 3 is tightly combined with the sealing ring 14, and the sealing ring 14 is tightly combined with the zinc sulfide glass sheet. The deformation of the pressure balance ring 13 can release stress, avoid generating local high pressure on the zinc sulfide glass sheet, and enhance the stability of the window. The pressure balance ring 13 can act as a buffer during the heating of the window, avoiding the influence of thermal expansion and contraction of materials on the vacuum stability.

[0041] The end of the gas output pipeline 5 is equipped with a VCR or CF16 joint. In this embodiment, by sinking the zinc sulfide glass into the base 3 of the laser window, the volume occupied by the window is greatly compressed, and by tightly connecting the heating element 7 with the sample cavity 4, the temperature control ability of the sample cell is improved. The setting of the fixing plate 12 enables this sample cavity to be applicable to different installation environments. In this embodiment, the volume of the zinc sulfide window is as small as 9 cm 3 , which is much smaller than the current commercial window (80 cm 3 ).

[0042] The above detailed description is a specific description of the feasible embodiments of the present invention, and this embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification without departing from the present invention shall be included in the patent scope of this case.

Claims

1. A sample chamber suitable for laser-heated argon-argon dating analysis, characterized in that: The invention comprises a laser window, a sample pool, a gas release module for heating and releasing gas from the sample pool, a fixing plate and a lifting rod with an adjustable height function; the sample pool comprises a sample cavity and a gas output pipeline, the sample cavity is recessed from top to bottom to form a countersunk hole for placing the sample, and the gas output pipeline is connected to the countersunk hole; the laser window comprises a base, a sealing ring, a pressure balance ring, a zinc sulfide glass sheet and a top plate, the middle of the base is provided with a lower through hole penetrating the upper and lower sides thereof, and the top plate is provided with an upper through hole penetrating the upper and lower sides thereof; the base is mounted on the sample cavity. The lower through hole is opposite to the countersunk hole and is connected together, and the upper section of the lower through hole is recessed outward to form a countersunk hole; the zinc sulfide glass sheet is sleeved at the countersunk hole of the lower through hole, the sealing ring is sleeved at the lower end of the zinc sulfide glass sheet, the pressure balance ring is sleeved at the upper end of the zinc sulfide glass sheet, the top plate is fixed to the base by screws, and the zinc sulfide glass sheet is located below the upper through hole; the lower part of the sample cavity is connected to the upper end of the lifting rod, and the lower end of the lifting rod is installed on the fixed plate; the gas release module wraps the outside of the sample cavity.

2. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: A gasket made of oxygen-free copper is arranged between the sample cavity and the base.

3. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: The gas release module includes a heating element, a thermocouple, an insulation box and a temperature control unit; the heating element is a heating plate, a heating block or a heating wire; the insulation box includes part or the entire sample cavity and is installed on the sample cavity by screws; the thermocouple is in contact with the sample cavity and monitors the temperature of the sample cavity in real time; the temperature control unit is connected to the heating element and performs temperature control on it, and the temperature control unit includes temperature rise control, constant temperature control and temperature drop control.

4. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: The lifting rod includes a fixed rod, a screw rod and a fixed nut; the upper end of the screw rod is connected to the lower part of the sample chamber, the lower end of the screw rod is sleeved in the fixed rod and can slide along the inner wall thereof, the fixed nut is installed on the fixed rod and locks or loosens the screw rod by rotation; the lower end of the fixed rod is installed on the fixed plate.

5. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: The fixing plate is provided with a plurality of through holes which are distributed at equal intervals.

6. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 5, characterized in that: The diameter of the through hole is 6 mm, and the spacing between adjacent through holes is 5-20 mm.

7. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: The diameter of the countersunk hole is 40-80 mm, and its depth is 8-20 mm; the inner diameter of the gas output pipeline is 6-18 mm, and its length is 10-50 mm; the diameter of the lower through hole is 30-70 mm, and the diameter of the countersunk hole is 40-80 mm.

8. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 1, characterized in that: The sealing ring is a metal sealing ring.

9. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 8, characterized in that: The sealing ring is made of pure metal or alloy material with a Vickers hardness range of 8-60HV.

10. The sample chamber suitable for laser-heated argon-argon dating analysis according to claim 8 or 9, characterized in that: The sealing ring is made of gold, silver, indium, tin, bismuth or babbitt alloy.

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