Ion source structure and thermal ionization mass spectrometer

Abstract

The present invention discloses an ion source structure, which includes an ion source chamber, a sample turntable, an ion lens group, and a shielded glove box. The front of the ion source chamber is sealed and connected to the shielded glove box, and a door hole is provided on the front of the ion source chamber, and an ion source chamber door is provided on the door hole. The ion source chamber door is in the shielded glove box and is opposite to the operating surface of the shielded glove box; the sample turntable and the ion lens group are both arranged inside the ion source chamber, and the ion lens group, the sample turntable, the ion source chamber door, and the shielded glove box are linearly arranged in the horizontal direction in sequence. The present invention also discloses a thermal ionization mass spectrometer. The present invention can be applied to the detection of radioactive samples, effectively realizes the isotope abundance or abundance ratio analysis of radioactive samples, and is easy to disassemble, clean and replace, and can ensure long-term and stable operation.

Description

Technical Field

[0001] The invention belongs to the technical field of analysis, and in particular relates to an ion source structure and a thermal ionization mass spectrometer comprising the ion source structure. Background Art

[0002] Thermal ionization mass spectrometry (TI MS) is an analytical testing technology developed in the 1970s for the precise measurement of element isotope abundance and isotope abundance ratio. Compared with other analytical techniques, thermal ionization mass spectrometry has the advantages of high accuracy and precision, and is widely used in nuclear industry, environment, geology, archaeology and other fields.

[0003] In the nuclear fuel reprocessing analysis process, the abundance analysis and nuclear material balance of nuclear materials are key analysis items that require precise analysis to ensure nuclear criticality safety. Thermal ionization mass spectrometry is an essential method widely used in reprocessing plants at home and abroad. The ion source is the key part of the thermal ionization mass spectrometer, and its performance directly determines the key performance indicators of the thermal ionization mass spectrometer, such as sensitivity and detection limit.

[0004] At present, the ion sources used in mainstream thermal ionization mass spectrometer products have their own specific designs and characteristics. Although they can basically achieve high ionization efficiency and ion transmission efficiency, they are not suitable for radioactive sample analysis and are difficult to disassemble and clean. After a period of use, various performance indicators have dropped significantly, but they cannot be improved due to inconveniences in maintenance and replacement. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an ion source structure and a thermal ionization mass spectrometer for the above-mentioned deficiencies in the prior art, which can be applied to the detection of radioactive samples, effectively realize the isotope abundance or abundance ratio analysis of radioactive samples, and can be easily disassembled and cleaned, and conveniently maintained and replaced, thereby ensuring long-term and stable operation.

[0006] The technical solution of the present invention to solve the above technical problems is:

[0007] According to one aspect of the present invention, an ion source structure is provided, which includes an ion source chamber, a sample turntable, an ion lens group, and a shielded glove box, wherein: the front portion of the ion source chamber is sealed and connected to the shielded glove box, and a door hole is provided on the front portion of the ion source chamber, an ion source chamber door is provided on the door hole, the ion source chamber door is located in the shielded glove box and is opposite to the operating surface of the shielded glove box; the sample turntable and the ion lens group are both arranged inside the ion source chamber, and the ion lens group, the sample turntable, the ion source chamber door, and the shielded glove box are linearly arranged in sequence in the horizontal direction.

[0008] Preferably, the ion source chamber door is arched, and the top of the arched ion source chamber door faces the shielding glove box.

[0009] Preferably, the ion source chamber door is a compression door, and the distance between the ion source chamber and the operating surface of the shielding glove box is 350-450 mm.

[0010] Preferably, the shielded glove box includes a box body, a glove chuck, an ion source flange interface, an article transfer channel, an air inlet filter, and an exhaust filter, the front portion of the box body is the operating surface, the glove chuck is arranged on the operating surface, a shielding glove is provided on the glove chuck, and the box body is provided with an air inlet and an air outlet, the air inlet filter is arranged on the air inlet, and the air outlet filter is arranged on the air outlet; the ion source flange interface is arranged at the rear portion of the box body, for connecting to the front portion of the ion source chamber; the article transfer channel is arranged on the left or right side of the box body, for allowing articles to pass through when entering and exiting the box body.

[0011] Preferably, the sealing level of the shielding glove box is level 3, and the dimensions of the box body are: 900mm×350mm×700mm.

[0012] Preferably, the present structure also includes a turntable drive device and a high-voltage connector, wherein the turntable drive device is disposed on one of the left and right sides of the ion source chamber and is connected to the sample turntable for driving the sample turntable to rotate; the high-voltage connector is disposed on the other of the left and right sides of the ion source chamber and is electrically connected to the sample turntable, the turntable drive device, and the ion lens group, respectively, to provide stable and adjustable current and voltage.

[0013] Preferably, the sample turntable includes a sample holder, a turntable, a rotating shaft, a support rod, a positioning ring, and a chuck, one end of the support rod is connected to the ion lens group, and the other end of the support rod is rotatably connected to the rotating shaft, so that the sample turntable and the ion lens group are relatively fixed; the turntable is arranged on the rotating shaft, and the number of the sample holders is multiple, and the multiple sample holders are all arranged on the turntable and distributed in a ring along the circumferential direction of the turntable, each sample holder provides a sample position for placing the sample, and the sample position is provided with an evaporation belt and an ionization belt, which are respectively used to evaporate and ionize the sample, the chuck is arranged on the rotating shaft and connected to the turntable driving device, and is used to cooperate with the turntable driving device to drive the rotating shaft to rotate and drive the turntable to rotate; the positioning ring is fixed on the turntable, and is provided with an indicator mark, and each indicator mark corresponds to a sample holder.

[0014] Preferably, the high-voltage connector adopts an aviation plug, which includes a body and a shell. The body is arranged in the shell, and a 15-core pin is arranged on the body. The shell is a glass insulating shell, and the insulation requirement between the pin and the shell is above 15KV.

[0015] Preferably, the present structure also includes a liquid nitrogen cooling hydrazine and a vacuum interface, wherein the liquid nitrogen cooling hydrazine is arranged at the top of the ion source chamber, and is used to condense the substances scattered by the heated ionization of the sample during the test process; the vacuum interface is arranged at the bottom of the ion source chamber, and is used to connect the vacuum pumping equipment to vacuum the ion source chamber.

[0016] According to another aspect of the present invention, a thermal ionization mass spectrometer is provided, which includes an ion source, and the ion source adopts the ion source structure described above.

[0017] The ion source structure of the present invention has a reasonable layout, a simple structure, and good sealing performance. It can be applied to the detection of radioactive samples and effectively realizes the isotope abundance or abundance ratio analysis of radioactive samples. In addition, it is convenient to disassemble, clean, overhaul and replace components such as an ion lens group in the ion source chamber, thereby ensuring the performance such as ionization efficiency and particle transmission efficiency, and realizing long-term and stable operation.

[0018] A thermal ionization mass spectrometer of the present invention has good sealing performance due to the adoption of the above-mentioned ion source structure, and can be applied to the detection of radioactive samples. In addition, it is easy to disassemble. When various performance indicators of the thermal ionization mass spectrometer drop significantly after being used for a period of time, it is convenient to disassemble, clean, overhaul and replace components such as the ion lens group in the ion source chamber, thereby ensuring the ionization efficiency, particle transmission efficiency and other performances, and realizing long-term and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of an ion source structure in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of a shielded glove box in an embodiment of the present invention;

[0021] Figure 3 It is a structural schematic diagram of a turntable driving device in an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of the structure of the sample turntable in the embodiment of the present invention.

[0023] In the figure: 1-shielded glove box; 2-ion source chamber door; 31-sample turntable; 32-ion lens group; 4-ion source chamber; 5-turntable drive device; 6-sealing flange; 7-high voltage connector; 8-vacuum interface; 9-liquid nitrogen cold trap; 10-exhaust filter; 11-box; 12-ion source flange interface; 13-item transfer channel; 14-inlet filter; 15-glove chuck; 16-sample holder; 17-turntable; 18-rotating shaft; 19-support rod; 20-positioning ring; 21-chuck; 22-reducer; 23-stepping motor; 24-adjusting mechanism. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0025] In the description of the present invention, it should be noted that the directions or positional relationships indicated by “upper” and the like are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience and simplification of the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0026] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connect", "set", "install", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example 1

[0029] like Figure 1As shown, this embodiment discloses an ion source structure, which includes an ion source chamber 4, a sample turntable 31, an ion lens group 32, and a shielding glove box 1, wherein:

[0030] The front part of the ion source chamber 4 is sealed with the shielding glove box 1 through a sealing flange 6, and a door hole is opened on the front part, and an ion source chamber door 2 is provided on the door hole. The ion source chamber door 2 is used to block the door hole, and the ion source chamber door 2 is located in the shielding glove box 1 and is opposite to the operating surface of the shielding glove box 1 (that is, the side with the shielding gloves).

[0031] The sample turntable 31 and the ion lens group 2 are both disposed inside the ion source chamber 4 , and the ion lens group 32 , the sample turntable 31 , the ion source chamber door 2 , and the shielding glove box 1 are linearly arranged in sequence in the horizontal direction.

[0032] The ion source structure of this embodiment has good sealing performance due to the unique layout design mentioned above. The operator can load samples and perform analysis through the shielding gloves on the shielding glove box 1. It can be applied to the detection of radioactive samples and effectively realize the isotope abundance or abundance ratio analysis of radioactive samples. In addition, the operator can use the shielding gloves on the shielding glove box 1 to easily disassemble, clean, inspect and replace components such as the ion lens group in the ion source room, thereby ensuring long-term and stable operation.

[0033] It should be noted that the ion source structure of this embodiment is not only applicable to the detection of radioactive samples, but also can be applied to the detection of other non-radioactive samples.

[0034] In some embodiments, the ion source chamber door 2 is arched, for example, a hemispherical arch design can be adopted, and the top of the arched ion source chamber door 2 faces the shielding glove box 1, that is, the ion source chamber door 2 protrudes into the shielding glove box 1, thereby shortening the distance between the ion lens group 32, the sample turntable 31 and other components in the ion source chamber 4 and the operating surface of the shielding glove box 1, thereby facilitating disassembly, inspection, replacement and other operations.

[0035] In some embodiments, the ion source chamber door 2 is preferably a compact door that can be easily disassembled, and the distance between the ion source chamber 4 and the operating surface of the shielding glove box 1 is no more than 450 mm.

[0036] In this embodiment, the distance between the ion source chamber 4 and the operating surface of the shielding glove box 1 is preferably 350-450 mm to ensure the convenience of operations such as replacement and maintenance of the ion lens group.

[0037] In some embodiments, Figure 2 As shown, the shielding glove box 1 includes a box body 11, a glove chuck 15, an ion source flange interface 12, an article transfer channel 13, an air inlet filter 14, and an exhaust filter 10.

[0038] Specifically, the front of the box body 11 is the operating surface, and the glove chuck 15 is arranged on the operating surface. The glove chuck 15 is provided with the shielding gloves, and the operator can also perform operations such as spotting, coating, and loading on the radioactive samples through the shielding gloves. The box body 11 is provided with an air inlet and an air outlet. The air inlet filter 14 is arranged on the air inlet to prevent dust and other impurities from entering the box body, and the air outlet filter 10 is arranged on the air outlet to prevent the leakage of radioactive substances. The width of the box body 11 is preferably not more than 450mm, preferably 300-450mm. The ion source flange interface 12 is arranged at the rear of the box body 11, and is used to connect to the front of the ion source chamber 4. That is to say, the shielding glove box 1 is in front of the ion source chamber 4. The sealing flange 6 is arranged on the ion source flange interface 12, and the ion source chamber 4 is sealed and connected to the box body 11 of the shielding glove box 1 through the sealing flange 6. The article transfer channel 13 is arranged on the left or right side of the box body 11, such as Figure 2 As shown, the article transfer channel 13 is preferably arranged on the right side of the box body 11 and at the lower part of the box body 11, and is used for samples, ion lens groups and other articles to pass through when entering and leaving the box body.

[0039] In this embodiment, the sealing level of the shielding glove box 1 is preferably level 3, with good radioactive containment, and the length, width and height dimensions of the box body 11 of the shielding glove box 1 are preferably: 900mm×350mm×700mm.

[0040] In some embodiments, the ion source structure also includes a turntable drive device 5 and a high-voltage connector 7, wherein: the turntable drive device 5 is disposed on one of the left and right sides of the ion source chamber 4, and is sealed and connected to the ion source chamber 4 by means of a sealing flange or the like to ensure that the ion source chamber 4 is in a high vacuum state, and is connected to the sample turntable 31 to drive the sample turntable 31 to rotate to switch samples; the high-voltage connector 7 is disposed on the other of the left and right sides of the ion source chamber 4, and is electrically connected to the sample turntable 31, the turntable drive device 5, and the ion lens group 32, respectively, to provide stable and adjustable current and voltage.

[0041] Specifically, if Figure 3As shown, the turntable driving device 5 includes a reducer 22, a stepper motor 23, and an adjustment mechanism 24, wherein the stepper motor 23 is connected to the sample turntable 31 to drive the sample turntable to rotate; the reducer 22 is connected to the stepper motor 23 through gear meshing, and the adjustment mechanism 24 is connected to the stepper motor 23 and the reducer 22 respectively, so as to control the rotation and stop of the sample turntable 31 by controlling the start and stop of the stepper motor 23 and the reducer 22, thereby switching samples. More specifically, the adjustment mechanism 24 may include an automatic control module, which is electrically connected to the stepper motor 23 and the reducer 22 respectively, and a control software is provided in the automatic control module to control the start and stop of the stepper motor 23 and the reducer 22 by inputting computer instructions, thereby driving the sample turntable 31 to rotate and position, and realizing sample switching. Of course, the adjustment mechanism 24 may also include a manual control module, which is electrically connected to the stepper motor 23 and the reducer 22 respectively, and is used for the operator to manually control the start and stop of the stepper motor and the reducer.

[0042] The high-voltage connector 7 adopts an aviation plug, which is fixed on the ion source chamber through a sealing flange and connected to an external high-voltage power supply module. The aviation plug includes a body and a shell, and the body is provided with 15 pins, that is, a 15-core pin is adopted. The shell is preferably a glass insulating shell, and the insulation requirement between the pin and the shell is above 15KV.

[0043] In some embodiments, Figure 4 As shown, the sample turntable 31 includes a sample holder 16 , a turntable 17 , a rotation axis 18 , a support rod 19 , a positioning ring 20 , and a chuck 21 .

[0044] Specifically, one end of the support rod 19 is connected to the ion lens group 32, and the other end of the support rod 19 is rotatably connected to the shaft 18, that is, when the shaft 18 rotates, the support rod 19 does not rotate with the shaft 18, so that the sample turntable 31 and the ion lens group 32 are relatively fixed. The turntable 17 is circular, which is arranged on the shaft 18 and rotates with the shaft 18. The number of sample holders 16 is preferably multiple, and multiple sample holders 16 are arranged on the turntable 17 and distributed in a ring along the circumferential direction of the turntable 17. Each sample holder 16 provides a sample position for placing the sample, and each sample holder 16 adopts a dual-belt mode design, and an evaporation belt and an ionization belt are provided on the sample position for evaporating and ionizing the sample, which can be suitable for nanogram content and a wide mass range (Li 6 to U 238The chuck 21 is arranged on the rotating shaft 18 and is at the end of the rotating shaft 18. The chuck 21 can play a fixing role. In addition, the chuck 21 is also connected to the output end of the stepper motor in the turntable drive device 5 to cooperate with the turntable drive device to drive the rotating shaft 18 to rotate and drive the turntable 17 to rotate, so as to rotate and switch the samples at different sample positions to the detection position to realize sample switching. The positioning ring 20 is fixed on the turntable 17 and is provided with an indicator mark. Each indicator mark corresponds to a sample holder, so that the required sample can be selected according to the indicator mark and the sample currently being detected can be identified.

[0045] In this embodiment, the number of the sample holders 16 is preferably greater than or equal to 11, that is, at least 11 sample positions are provided on the sample turntable 31 .

[0046] In some embodiments, the ion source structure also includes a turntable drive device 5 and a high-voltage connector 7, wherein: the turntable drive device 5 is disposed on one of the left and right sides of the ion source chamber 4, and is connected to the sample turntable 31, and is used to drive the sample turntable 31 to rotate to switch samples; the high-voltage connector 7 is disposed on the other of the left and right sides of the ion source chamber 4, and is electrically connected to the sample turntable 31, the turntable drive device 5, and the ion lens group 32, respectively, to provide stable and adjustable current and voltage.

[0047] Specifically, if Figure 4 As shown, the turntable driving device 5 includes a reducer 22, a stepper motor 23, and an adjustment mechanism 24, wherein the stepper motor 23 is connected to the sample turntable 31 to drive the sample turntable to rotate; the reducer 22 is connected to the stepper motor 23 through gear meshing, and the adjustment mechanism 24 is connected to the stepper motor 23 and the reducer 22 respectively, so as to control the rotation and stop of the sample turntable 31 by controlling the start and stop of the stepper motor 23 and the reducer 22, thereby switching samples. More specifically, the adjustment mechanism 24 may include an automatic control module, which is electrically connected to the stepper motor 23 and the reducer 22 respectively, and a control software is provided in the automatic control module to control the start and stop of the stepper motor 23 and the reducer 22 by inputting computer instructions, thereby driving the sample turntable 31 to rotate and position, and realizing sample switching. Of course, the adjustment mechanism 24 may also include a manual control module, which is electrically connected to the stepper motor 23 and the reducer 22 respectively, and is used for the operator to manually control the start and stop of the stepper motor and the reducer.

[0048] The high-voltage connector 7 adopts an aviation plug, which is fixed on the ion source chamber through a sealing flange and connected to an external high-voltage power supply module. The aviation plug includes a body and a shell, the body is arranged in the shell, and 15 pins are arranged on the body, that is, a 15-core pin is adopted, the shell is preferably a glass insulation shell, and the insulation requirement between the pin and the shell is above 15KV.

[0049] In some embodiments, the ion source structure also includes a vacuum interface 8 and a liquid nitrogen cooling hydrazine 9, wherein: the vacuum interface 8 is disposed at the bottom of the ion source chamber 4, and is used to connect a vacuum pumping device to evacuate the interior of the ion source chamber; the liquid nitrogen cooling hydrazine 9 is disposed at the top of the ion source chamber 4, and is used to condense substances scattered by the heated ionization of the sample during the test process, so as to prevent the introduction of impurities and affect the detection and analysis results.

[0050] Specifically, the vacuum interface 8 can be a flange interface made of stainless steel, and the vacuum device can be a turbomolecular pump. The pumping rate of the turbomolecular pump can be about 255L / S to pump the ion source chamber to 5×10 -8 Vacuum above mbar.

[0051] The liquid nitrogen cooling hydrazine 9 includes a cylindrical liquid nitrogen bottle and a flange seat. The liquid nitrogen bottle is fixed to the top of the ion source chamber 4 through the flange seat. The body of the liquid nitrogen bottle is inside the ion source chamber 4. Liquid nitrogen is stored in the liquid nitrogen bottle. The liquid nitrogen bottle can provide a surface with a very low temperature. When the substances scattered by the heated ionization in the sample gather on the low-temperature surface, they are condensed. In addition, due to the existence of the above-mentioned condensation process, the vacuum degree in the ion source chamber can also be improved.

[0052] The ion source structure of the present embodiment has a reasonable layout, a simple structure, and good sealing performance. By arranging the ion lens group, the sample turntable, the ion source chamber door, and the shielding glove box linearly in the horizontal direction, the operator can load and analyze the sample through the shielding gloves on the shielding glove box. It can be applied to the detection of radioactive samples and effectively realize the isotope abundance or abundance ratio analysis of radioactive samples. In addition, the operator can also use the shielding gloves on the shielding glove box to facilitate the disassembly, cleaning, maintenance and replacement of the ion lens group and other components in the ion source chamber, thereby ensuring the ionization efficiency, particle transmission efficiency and other performance, and realizing long-term and stable operation.

[0053] Example 2

[0054] This embodiment discloses a thermal ionization mass spectrometer, which includes multiple components such as an ion source, a magnetic field mass analyzer, a detector system, and a measurement and control and software system. The ion source adopts the ion source structure described in Example 1.

[0055] The thermal ionization mass spectrometer of this embodiment adopts the ion source structure described in Example 1, has good sealing performance, can be applied to the detection of radioactive samples, and is easy to disassemble. When various performance indicators of the thermal ionization mass spectrometer drop significantly after being used for a period of time, the ion lens group and other components in the ion source chamber can be easily disassembled, cleaned, repaired and replaced, thereby ensuring the ionization efficiency, particle transmission efficiency and other performances, and achieving long-term and stable operation.

[0056] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An ion source structure, characterized in that: Including ion source chamber, sample turntable, ion lens set, and shielded glove box, The front part of the ion source chamber is sealed with the shielding glove box, and a door hole is opened on the front part of the ion source chamber, and an ion source chamber door is arranged on the door hole. The ion source chamber door is in the shielding glove box and is opposite to the operation surface of the shielding glove box; The sample turntable and the ion lens group are both arranged inside the ion source chamber, and the ion lens group, the sample turntable, the ion source chamber door, and the operating surface of the shielding glove box are linearly arranged in sequence in the horizontal direction.

2. The ion source structure according to claim 1, characterized in that: The ion source chamber door is arched, and the top of the arched ion source chamber door faces the shielding glove box.

3. The ion source structure according to claim 2, characterized in that: The ion source chamber door is a compression door, and the distance between the ion source chamber and the operating surface of the shielding glove box is 350-450 mm.

4. The ion source structure according to claim 1, characterized in that: The shielded glove box includes a box body, a glove chuck, an ion source flange interface, an article transfer channel, an air inlet filter, and an exhaust filter. The front part of the box body is the operating surface, the glove chuck is arranged on the operating surface, the glove chuck is provided with a shielding glove, and the box body is provided with an air inlet and an air outlet, the air inlet filter is arranged on the air inlet, and the air outlet filter is arranged on the air outlet; The ion source flange interface is arranged at the rear of the housing and is used to connect to the front of the ion source chamber; The article transfer channel is arranged on the left side or the right side of the box body, and is used for articles to pass through when entering or leaving the box body.

5. The ion source structure according to claim 4, characterized in that: The sealing level of the shielding glove box is level 3, and the length, width and height of the box are: 900mm×350mm×700mm.

6. The ion source structure according to any one of claims 1 to 5, characterized in that: Also includes turntable drive and high voltage connectors, The turntable driving device is disposed on one of the left and right sides of the ion source chamber and is connected to the sample turntable, and is used to drive the sample turntable to rotate; The high voltage connector is arranged on the other of the left and right sides of the ion source chamber, and is electrically connected to the sample turntable, the turntable driving device, and the ion lens group respectively to provide stable and adjustable current and voltage.

7. The ion source structure according to claim 6, characterized in that: The sample turntable comprises a sample support, a turntable, a rotating shaft, a support rod, a positioning ring, and a chuck. One end of the support rod is connected to the ion lens group, and the other end of the support rod is rotatably connected to the rotating shaft, so that the sample turntable and the ion lens group are relatively fixed; The turntable is arranged on the rotating shaft, and the number of the sample holders is multiple, and the multiple sample holders are arranged on the turntable and distributed in a ring shape along the circumferential direction of the turntable, and each sample holder provides a sample position for placing a sample. The sample position is provided with an evaporation zone and an ionization zone, which are used to evaporate and ionize the sample respectively. The chuck is arranged on the rotating shaft and connected to the turntable driving device, and is used to cooperate with the turntable driving device to drive the rotating shaft to rotate and drive the turntable to rotate; The positioning ring is fixed on the turntable and is provided with indication marks, each indication mark corresponding to a sample holder.

8. The ion source structure according to claim 6, characterized in that: The high voltage connector adopts an aviation plug, which includes a body and a shell. The main body is arranged in the shell, and 15-core plug pins are arranged on the main body. The shell is a glass insulating shell, and the insulation requirement between the plug pins and the shell is above 15KV.

9. The ion source structure according to claim 6, characterized in that: It also includes liquid nitrogen cooling and vacuum interfaces. The liquid nitrogen cooling hydrazine is arranged at the top of the ion source chamber, and is used to condense the substances scattered by the sample when it is heated and ionized during the test process; The vacuum interface is arranged at the bottom of the ion source chamber and is used to connect a vacuum pumping device to evacuate the ion source chamber.

10. A thermal ionization mass spectrometer, comprising an ion source, characterized in that: The ion source adopts the ion source structure described in any one of claims 1-9.

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