Automatic sample changing sample rod for neutron scattering experiment

Abstract

An automatic sample changing sample rod for a neutron scattering experiment comprises: a support rod, a first end of which is inserted into a sample tube from an opening of the sample tube and a second end of which is located outside the sample tube; the heat insulation part is arranged on the supporting rod in a sleeving manner; the sample seat is fixedly arranged at the first end; the sample seat is used for placing at least two samples, and the samples are arranged at intervals along the length direction; the fixing part is used for being connected with the cryostat and sealing the sample tube; the fixing piece is arranged on the supporting rod in a sleeving mode, the fixing piece and the supporting rod are mutually sealed at the connecting position, and the fixing piece and the supporting rod can relatively move in the length direction. The sample seat is provided with at least two samples which are arranged at intervals along the length direction, and the supporting rod and the fixing piece are in sealed movable connection, so that the sample corresponding to the neutron beam window in position can be changed by adjusting the relative position between the supporting rod and the fixing piece, the sample changing process is simplified, and the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to neutron scattering experiment technical field, concretely relates to a kind of automatic sample change sample rod for neutron scattering experiment. BACKGROUND

[0002] Cryostat is a kind of equipment that can provide low-temperature environment for neutron scattering experiment, considering the scarcity of liquid helium and operation safety, low-temperature equipment can be dry type without liquid helium type, using GM refrigerator provides cold source, through heat conduction band, the cold quantity of refrigerator is transmitted to sample tube, a certain high-purity helium gas is filled in sample tube, the low temperature of sample tube can be transmitted to sample, so as to realize sample cooling down;The sample to be measured is set behind sample seat, fixed on sample rod, then sample rod can be inserted into cryostat, and neutron beam window on sample tube is opposite to carry out neutron scattering experiment.Under this structure, if sample replacement is carried out, the entire sample rod must be taken out from sample tube, the sample on the sample seat of previous sample is replaced, and then the sample rod is inserted into sample tube, the sample changing process is relatively cumbersome, leading to low detection efficiency. SUMMARY

[0003] The utility model mainly solves the technical problems of the sample changing means of neutron scattering experiment in the related art is cumbersome, and the detection efficiency is low.

[0004] To solve the above technical problems, an automatic sample changing sample rod for neutron scattering experiment is provided in the embodiments of the present application, which is used for a sample tube in a cryostat;It comprises:

[0005] A support rod has a first end and a second end opposite along its length direction, the first end is inserted into the sample tube from the opening of the sample tube, and the second end is located outside the sample tube;

[0006] A heat insulating member is provided on the support rod;

[0007] A sample seat is fixedly provided on the first end;The sample seat is used for placing at least two samples, and each sample is spaced apart along the length direction;

[0008] A fixing member is used for connecting with the cryostat and sealing the sample tube;The fixing member is provided on the support rod, the fixing member and the support rod are sealed at the connection, and the fixing member and the support rod can move relative to each other along the length direction.

[0009] In one embodiment, the fixing member comprises an end cap and an elastic sealing ring; the end cap has an assembly through hole extending along the length direction; the elastic sealing ring is sleeved on the support rod, and the elastic sealing ring and the support rod are sleeved in the assembly through hole; the elastic sealing ring elastically abuts against the inner wall of the assembly through hole and the outer wall of the support rod.

[0010] In one embodiment, the fixing member further comprises at least two sleeves, the sleeves are sequentially sleeved on the support rod along the length direction, and the sleeves are sleeved in the assembly through hole; the elastic sealing ring is clamped between adjacent sleeves.

[0011] In one embodiment, the elastic sealing ring comprises at least two, the number of sleeves matches the number of elastic sealing rings, and each elastic sealing ring is arranged apart from each sleeve.

[0012] In one embodiment, the fixing member further comprises a top cap and a bottom cap, the top cap and the bottom cap are respectively arranged at both ends of the end cap along the length direction, and the top cap and the bottom cap respectively cover the openings at both ends of the assembly through hole; the top cap and the bottom cap are fixedly connected with the end cap, and the top cap and the bottom cap clamp and fix the sleeves and the elastic sealing rings in the length direction.

[0013] In one embodiment, the sample seat has at least two sample boxes arranged apart along the length direction, and the sample boxes are used for placing the samples.

[0014] In one embodiment, the positioning member comprises a limiting flange sleeved on the support rod and a plurality of elastic top beads arranged along the circumferential edge of the limiting flange; each elastic top bead is symmetrically arranged about the center point of the limiting flange, and the elastic top bead elastically abuts against the inner wall of the sample tube.

[0015] In one embodiment, the heat insulation member comprises at least two, and each heat insulation member is arranged apart along the length direction.

[0016] In one embodiment, the temperature controller is arranged on the sample seat and is used for controlling the working temperature of the sample seat.

[0017] In one embodiment, the heat insulation member is provided with a wire hole for the wire to pass through.

[0018] According to the automatic sample changing sample rod for neutron scattering experiments in the above embodiment, since the sample seat is provided with at least two samples arranged at intervals along the length direction, and the sealing movable connection is formed between the support rod and the fixing member, the sample corresponding to the position of the neutron beam window can be changed by adjusting the relative position between the support rod and the fixing member, so that the sample changing process is simplified, and the detection efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A schematic diagram of a low-temperature thermostat structure in the related art.

[0020] Figure 2 A schematic diagram of an automatic sample changing sample rod structure in the embodiment of the application.

[0021] Figure 3 A schematic diagram of the connection between the fixing member and the support rod in the embodiment of the application.

[0022] Figure 4 A schematic diagram of the elastic sealing ring and the sleeve sleeve set on the support rod in the embodiment of the application.

[0023] Figure 5 A schematic diagram of the fixing member structure in the embodiment of the application.

[0024] Figure 6 A schematic diagram of the fixing member structure in the embodiment of the application.

[0025] Figure 7 A schematic diagram of the positioning member structure in the embodiment of the application.

[0026] Figure 8 A schematic diagram of the elastic top bead structure in the embodiment of the application.

[0027] Figure 9 A schematic diagram of the support rod structure in which the clamp is arranged in the embodiment of the application.

[0028] Figure 10 A schematic diagram of the clamp structure in the embodiment of the application.

[0029] BRIEF DESCRIPTION OF DRAWINGS

[0030] 11-refrigerator; 12-heat conducting member; 13-sample tube; 14-heat shield; 15-neutron beam window; 16-vacuum cover; 17-sample rod;

[0031] 2-support rod;

[0032] 3-heat insulating member; 31-wiring hole;

[0033] 4-sample seat; 41-sample box;

[0034] 5 - fixing member; 51 - end cap; 52 - elastic sealing ring; 53 - assembly through hole; 54 - sleeve; 55 - top cover; 56 - bottom cover; 57 - vacuum electric connector;

[0035] 6 - positioning member; 61 - limiting flange; 62 - elastic top bead; 63 - top bead; 64 - spring;

[0036] 7 - clamp. DETAILED DESCRIPTION

[0037] The utility model will be further described in detail below by means of specific embodiments in connection with the drawings. In different embodiments, similar elements are provided with similar element reference numbers. In the following embodiments, many details are described in order to make the present application better understood. However, those skilled in the art can easily realize that some features can be omitted in different cases or replaced by other elements, materials or methods. In some cases, some operations related to the present application are not shown or described in the specification in order to avoid the core part of the present application being overwhelmed by too much description, and it is not necessary to describe these related operations in detail for those skilled in the art according to the description in the specification and general technical knowledge in the art.

[0038] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. Meanwhile, the steps or actions in the method description can also be sequentially adjusted or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for the purpose of clearly describing a certain embodiment, and do not mean that the sequence is necessary, unless otherwise stated that a certain sequence must be followed.

[0039] The serial numbers of components in this paper, such as "first", "second", etc., are only used to distinguish the described objects, and have no sequence or technical meaning. Unless otherwise specified, the "connection" and "coupling" in this application include direct and indirect connection (coupling).

[0040] Neutron scattering is a commonly used technique for studying the microstructure of matter, which is used to study the structure and dynamics of materials. Low temperature can promote the in-depth study of neutron in the field of material science, condensed matter physics and other related fields. The role of low temperature in the field of neutron scattering includes: increasing scattering contrast, studying material magnetism, studying phase transition, detecting low-energy excitation, dynamics research, developing new materials, etc.

[0041] A cryostat is a device that can provide a low-temperature environment for neutron scattering experiments, and can provide a neutron test environment at low temperature for a neutron spectrometer. Considering the scarcity and safety of liquid helium, the low-temperature device can adopt a dry liquid-helium-free type. A GM refrigerator is used to provide a cold source, and the cold quantity of the refrigerator is transmitted to the sample tube through a heat-conducting band. The sample tube is filled with a certain amount of high-purity helium gas, so that the low temperature of the sample tube can be transmitted to the sample, thereby realizing sample cooling. The typical structure of the dry liquid-helium-free type cryostat is shown in Figure 1 , mainly including a refrigerator 11, a heat-conducting member 12, a sample tube 13, a heat shield 14, a neutron beam window 15, a vacuum cover 16, a sample rod 17, and the like. The sample to be measured is sealed and arranged at the rear of the sample seat 4, and the sample seat 4 is fixed on the sample rod 17, so that the sample rod 17 can be inserted into the sample tube 13 for cooling, and the sample is opposite to the neutron beam window 15, so that the neutron scattering experiment can be carried out.

[0042] In order to improve the sample exchange efficiency, the embodiment of the present application provides an automatic sample exchange sample rod for neutron scattering experiments, which is used in a sample tube in a cryostat; please refer to Figure 2 , the automatic sample exchange sample rod comprises:

[0043] A support rod 2 has a first end and a second end opposite along the length direction thereof, the first end is inserted into the sample tube from the opening of the sample tube, and the second end is located outside the sample tube;

[0044] A heat insulation member 3 is sleeved on the support rod 2;

[0045] A sample seat 4 is fixedly arranged at the first end; the sample seat 4 is used for placing at least two samples, and each sample is arranged at intervals along the length direction;

[0046] A fixing member 5 is used for connecting with the cryostat and sealing the sample tube; the fixing member 5 is sleeved on the support rod 2, the fixing member 5 and the support rod 2 are sealed at the connection position, and the fixing member 5 and the support rod 2 can move relative to each other along the length direction.

[0047] The automatic sample exchange sample rod in the embodiment of the present application is applied in neutron scattering experiments, especially matched with the cryostat. The cryostat has a sample tube, the sample tube is provided with a neutron beam window, the sample is arranged on the automatic sample exchange sample rod, and the automatic sample exchange sample rod is inserted into the sample tube, so that the sample on the automatic sample exchange sample rod is opposite to the neutron beam window, and the neutron scattering experiment can be carried out.

[0048] The automatic sample changing rod comprises a support rod 2, a heat insulation piece 3, a sample seat 4 and a fixing piece 5. The support rod 2 serves as the framework of the automatic sample changing rod, and other components are directly or indirectly arranged on the support rod 2. The support rod 2 can be an integral rod structure or a plurality of parts connected to each other, so that the support rod 2 has the telescopic feature and can be conveniently adjusted in length to be matched with the sample tube. In order to realize the telescopic feature, the support rod 2 can be formed by sleeving two or more connecting rods with nested inner diameters.

[0049] The neutron scattering experiment requires that the sample is in a constant temperature environment. In order to prevent the external temperature from affecting the sample in the sample tube, the support rod 2 is provided with the heat insulation piece 3. The heat insulation piece 3 can comprise one or more heat insulation pieces 3, and each heat insulation piece 3 is sequentially and spacedly arranged along the length direction. The heat insulation pieces 3 can be uniformly distributed or the intervals between the heat insulation pieces 3 can be unequal. The heat insulation piece 3 can block the space on both sides to a certain extent, thereby reducing heat conduction. The more heat insulation pieces 3 are arranged, the better the effect of isolating the space to reduce heat transfer. The heat insulation piece 3 can be in the form of a sheet, which can fill the cross section of the sample tube as much as possible to block the space on both sides and reduce heat transfer on both sides.

[0050] The sample seat 4 is arranged at the first end of the support rod 2, and the sample seat 4 is also located in the sample tube when the support rod 2 is inserted into the sample tube. A plurality of samples can be arranged on the sample seat 4, and each sample is spacedly arranged along the length direction of the support rod 2. Therefore, each sample can be switched to be opposite to the neutron beam window on the sample tube, and each sample can be selectively opposite to the neutron beam window, so that the neutron scattering experiment can be performed on the corresponding sample. If the position of the sample opposite to the neutron beam window is switched, the sample changing operation is completed.

[0051] Since the sample window in the embodiment of the present application is a sealed structure, in order to keep the sealed state even when the sample is switched, the sample rod in the embodiment of the present application further comprises a fixing member 5 which is used to be connected with the cryostat, and is arranged to seal the sample tube; in addition, the fixing member 5 is sleeved on the support rod 2, and the fixing member 5 and the support rod 2 are movably connected, wherein the fixing member 5 and the support rod 2 can move relative to each other along the length direction; at the same time, the fixing member 5 and the support rod 2 are sealed at the sleeved part, so that the sample tube can be kept in a sealed state without being connected with the outside world in the state that the fixing member 5 and the support rod 2 move relative to each other. Therefore, when the sample rod in the embodiment of the present application is applied to the cryostat, the first end of the support rod 2 with the heat insulating member 3 and the sample seat 4 is inserted into the sample tube, the fixing member 5 is fixed at the opening of the sample tube, so that the sample tube is in a sealed state, and the second end of the support rod 2 is located outside; in this state, by controlling the support rod 2 to move relative to the fixing member 5 along the length direction, the depth of the support rod 2 inserted into the sample tube can be adjusted without changing the sealed state of the sample tube, and different depths can make the samples arranged along the length direction selectively face the neutron beam window on the sample tube, so that the sample rod can be replaced without being disassembled, thereby greatly improving the detection efficiency.

[0052] In some optional embodiments, please refer to Figures 3-6As shown, in order to realize mutual sealing between the fixing member 5 and the support rod 2 at the connection, so that the relative movement between the support rod 2 and the fixing member 5 does not affect the sealing state of the sample tube, and the constant temperature state in the sample tube is not destroyed, the fixing member 5 can specifically include an end cover 51 and an elastic sealing ring 52; the end cover 51 has an assembly through hole 53 extending in the length direction; the elastic sealing ring 52 is sleeved on the support rod 2, and the elastic sealing ring 52 is sleeved in the assembly through hole 53 together with the support rod 2, and the elastic sealing ring 52 is elastically abutted against the inner wall of the assembly through hole 53 and the outer wall of the support rod 2. Among them, the end cover 51 in the embodiment of the application is directly plugged in the opening of the sample tube, and is directly or indirectly fixedly connected with the sample tube through a connecting member. The fixed connection is generally detachable, and the specific connecting member can include a threaded connecting member, a buckle and the like. The end cover 51 is formed with an assembly through hole 53 extending in the length direction, and the assembly through hole 53 penetrates the end cover 51 in the length direction, so that the end cover 51 can be sleeved on the support rod 2 through the assembly through hole 53. In order to realize sealing between the end cover 51 and the support rod 2 at the connection, the elastic sealing ring 52 is sleeved outside the support rod 2, and the elastic sealing ring 52 is sleeved in the assembly through hole 53 together with the support rod 2 sleeved therein. Due to the existence of the elastic sealing ring 52, the elasticity of the elastic sealing ring 52 can make the inner side of the elastic sealing ring 52 elastically abut against the outer wall of the support rod 2, and the outer side of the elastic sealing ring 52 elastically abut against the inner wall of the assembly through hole 53, so as to form a movable connection between the support rod 2 and the end cover 51. Even if the support rod 2 and the end cover 51 move relative to each other in the length direction, the sealing state can be maintained under the action of the elastic sealing ring 52.

[0053] In some optional embodiments, in order to enhance the sealing effect, the fixing member 5 further includes at least two sleeves 54, the sleeves 54 are sequentially sleeved on the support rod 2 in the length direction, and the sleeves 54 are sleeved in the assembly through hole 53; the elastic sealing ring 52 is clamped between adjacent sleeves 54. Among them, the elastic sealing ring 52 can include at least two, the number of sleeves 54 matches the number of elastic sealing rings 52, and each elastic sealing ring 52 is arranged in space with each sleeve 54. In other words, the sleeves 54 and the elastic sealing rings 52 can be sleeved on the support rod 2 in the embodiment of the application, and at least one elastic sealing ring 52 is arranged between each two sleeves 54, and each elastic sealing ring 52 can form a multiple sealing structure between the support rod 2 and the end cover 51, which can effectively enhance the sealing effect. Even if the sealing effect of a certain elastic sealing ring 52 fails, the sealing effect can still be maintained by other sealing rings. For example, please refer to Figure 3 and Figure 4Five sleeves 54 can be arranged, and one elastic sealing ring 52 is arranged between every two adjacent sleeves 54, so that there are four elastic sealing rings 52, which form a quadruple sealing structure and effectively improve the sealing performance between the support rod 2 and the fixing member 5. In addition, the shapes and sizes of the sleeves 54 can be the same or different, for example Figure 3 and Figure 4 The sleeves 54 in the above two embodiments have different sizes and shapes and can be adapted to the assembly hole 53.

[0054] In some optional embodiments, in order to prevent the components including the sealing ring and the sleeve 54 from being separated from the connection between the end cover 51 and the support rod 2, the fixing member 5 can further include a top cover 55 and a bottom cover 56, which are respectively arranged at the two ends of the end cover 51 along the length direction, and the top cover 55 and the bottom cover 56 respectively cover the openings at the two ends of the assembly hole 53; the top cover 55 and the bottom cover 56 are fixedly connected with the end cover 51, and the top cover 55 and the bottom cover 56 clamp and fix the sleeve 54 and the elastic sealing ring 52 in the length direction. When the top cover 55 and / or the bottom cover 56 are not connected to the end cover 51, the sleeve 54 and the elastic sealing ring 52 can be arranged in the assembly hole 53 of the end cover 51; then, the top cover 55 and the bottom cover 56 can be fixedly connected with the end cover 51, and the connection mode can be formed by a threaded connection member, a buckle or the like. Moreover, through the mutual extrusion between the top cover 55 and the bottom cover 56, the sleeve 54 can also extrude the elastic sealing ring 52, so that the elastic sealing ring 52 elastically expands in the circumferential direction, thereby improving the sealing effect of the elastic sealing ring 52.

[0055] In some optional embodiments, please continue to refer to Figure 2 In order to accommodate multiple samples, the sample seat 4 has at least two sample boxes 41 arranged at intervals along the length direction, and the sample boxes 41 are used to place samples. Since each sample box 41 is arranged at intervals along the length direction, the corresponding samples placed in each sample box 41 are also arranged at intervals along the length direction, and then by adjusting the depth of the support rod 2 inserted into the sample tube, the corresponding sample box 41 and the neutron beam window can be adjusted to be opposite to each other, thereby realizing the sample changing operation.

[0056] In some optional embodiments, when the sample rod is inserted into the sample tube, in order to allow the sample rod to be located at a specified position in the sample tube, for example, to allow the sample rod to be located on the axis of the sample tube, that is, to allow the axis of the support rod 2 to overlap with the axis of the sample tube, please refer to Figure 7 and Figure 8In this embodiment, a positioning element 6 can be provided on the support rod 2, allowing the positioning element 6 to cooperate with the inner wall of the sample tube to control the actual position of the sample rod within the sample tube. Specifically, the positioning element 6 may include a limiting flange 61 sleeved on the support rod 2, and a plurality of elastic top beads 62 arranged along the circumferential edge of the limiting flange 61. Each elastic top bead 62 is symmetrically arranged about the center point of the limiting flange 61, and elastically abuts against the inner wall of the sample tube. Each elastic top bead 62 can move elastically radially along the limiting flange 61, equivalent to forming a telescopic movement along the circumferential edge of the limiting flange 61. Since multiple elastic top beads 62 are arranged along the circumferential edge of the limiting flange 61, and each elastic top bead 62 cooperates with each other, when the support rod 2 is inserted into the sample tube, the elastic top beads 62 form elastic contact with the inner wall of the sample tube, and the elastic top beads 62 in each direction achieve elastic balance within the sample tube, thereby aligning the axis of the support rod 2 with the axis of the sample tube. The elastic top ball 62 can be directly or indirectly connected to the limiting flange 61 by the top ball 63 and the spring 64. The extension and contraction direction of the spring 64 is along the radial direction of the limiting flange 61. The number of elastic top balls 62 can be 3, 4, 5, 6, 8 or more. Each elastic top ball 62 is centrally symmetrically arranged around the center point of the limiting flange 61 to ensure that the elastic force of each elastic top ball 62 is balanced when the support rod 2 is inserted into the sample tube.

[0057] In some alternative embodiments, please continue to refer to Figure 2 In order to improve the heat insulation effect inside the sample tube, the heat insulation element 3 may specifically include at least two, and each heat insulation element 3 is spaced apart along the length direction.

[0058] In some alternative embodiments, a temperature controller may be included to regulate the ambient temperature of the sample. The temperature controller is disposed on the sample holder 4 and is used to control the operating temperature of the sample holder 4. The controller includes a temperature regulator and a temperature indicator, wherein the temperature indicator is used to characterize the current ambient temperature, and the temperature regulator is used to control the ambient temperature of the sample holder 4, that is, to adjust the ambient temperature of the sample. The real-time ambient temperature of the sample can be obtained by a temperature indicator such as a thermometer, and then the ambient temperature of the sample can be adjusted to a specified temperature by a temperature regulator such as a heater.

[0059] In some alternative embodiments, if the temperature controller is a wired device, please refer to the following for instructions on how to properly connect the temperature controller's wiring to an external source for power supply and drive control. Figure 2 The heat insulation component 3 is provided with a wiring hole 31 for wires to pass through. The wiring hole 31 can extend along the length of the support rod 2, passing through both sides of the heat insulation component 3 to form a through hole, allowing wires to pass through, that is, allowing the temperature controller's wiring to pass through. In addition, the positioning component 6 can also be provided with a corresponding wiring hole.

[0060] Please refer to Figure 5 and Figure 6 Vacuum connector 57 can also be provided on the fixing part 5 to form an electrical connection with the wiring of the temperature controller, while maintaining the sealed state in the sample tube. The vacuum connector 57 is used to realize the electrical connection between the inside and outside.

[0061] In addition, to position and fix the various components on support rod 2, please refer to... Figure 9 and Figure 10 The support rod 2 is also equipped with a clamp 7, which is fitted onto the support rod 2. The clamp 7 can be pre-fixed to the support rod 2 with components such as the heat insulation component 3 and the positioning component 6. The heat insulation component 3 and the positioning component 6 can be fixed based on the position set by the clamp 7, so the clamp 7 plays a positioning and guiding role for these components.

[0062] Furthermore, unlike the sample rods in existing technologies, in this embodiment, the relative movement between the support rod 2 and the fixing member 5 does not affect the sealing state of the sample tube. Therefore, the support rod 2 can be controlled by setting up a drive motor and slide rails, allowing it to move relative to the fixing member 5 without manual control, thus enabling remote sample changing. Moreover, in addition to relative movement, the support rod 2 can also rotate relative to the fixing member 5. Therefore, the sample rod in this embodiment also has the function of oriented sample crystals. For some single-crystal samples, the angle between the crystal plane and the neutron beam can be adjusted to allow for oriented neutron scattering experiments on that single-crystal sample.

[0063] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. An automated sample change sample rod for neutron scattering experiments for a sample tube to be set in a cryostat; characterized in that, The application relates to a sample tube support device for a low-temperature thermostat, which comprises the following parts: a support rod with a first end and a second end opposite to each other along the length direction of the support rod, the first end is inserted into the sample tube from the opening of the sample tube, and the second end is located outside the sample tube; a heat insulation part sleeved on the support rod; a sample seat fixedly arranged on the first end, the sample seat is used for placing at least two samples, and each sample is arranged at intervals along the length direction; a fixing part used for connecting with the low-temperature thermostat and sealing the sample tube, the fixing part is sleeved on the support rod, the fixing part and the support rod are sealed at the connecting position, and the fixing part and the support rod can move relative to each other along the length direction.

2. The autochange sample rod of claim 1 wherein, The fixing part comprises an end cover and an elastic sealing ring, the end cover has an assembly through hole extending along the length direction, the elastic sealing ring is sleeved on the support rod, and the elastic sealing ring and the support rod are arranged in the assembly through hole, and the elastic sealing ring is elastically abutted against the inner wall of the assembly through hole and the outer wall of the support rod.

3. The autochange sample rod of claim 2, wherein, The fixing part further comprises at least two sleeves, the sleeves are sequentially sleeved on the support rod along the length direction, and the sleeves are arranged in the assembly through hole; the elastic sealing ring is clamped between the adjacent sleeves.

4. The autochange sample rod of claim 3 wherein, The elastic sealing ring comprises at least two, the number of the sleeves matches the number of the elastic sealing rings, and each elastic sealing ring is arranged at intervals with each sleeve.

5. The autochange sample rod of claim 3 wherein, The fixing part further comprises a top cover and a bottom cover, the top cover and the bottom cover are arranged at two ends of the end cover along the length direction respectively, and the top cover and the bottom cover cover the openings at two ends of the assembly through hole respectively; the top cover and the bottom cover are fixedly connected with the end cover respectively, and the top cover and the bottom cover clamp and fix the sleeves and the elastic sealing rings in the length direction.

6. The autochange sample rod of any of claims 1-5, wherein, The sample seat has at least two sample boxes arranged at intervals along the length direction, and the sample boxes are used for placing the samples.

7. The autochange sample rod of any of claims 1-5, wherein, The application further comprises a positioning part, the positioning part comprises a limiting flange sleeved on the support rod and a plurality of elastic top beads arranged along the circumferential edge of the limiting flange; each elastic top bead is symmetrically arranged about the center point of the limiting flange, and the elastic top bead is elastically abutted against the inner wall of the sample tube.

8. The autochange sample rod of any of claims 1-5, wherein, The heat insulation part comprises at least two, and each heat insulation part is arranged at intervals along the length direction.

9. The autochange sample rod of any of claims 1-5, wherein, The application further comprises a temperature controller arranged on the sample seat and used for controlling the working temperature of the sample seat.

10. The autochange sample rod of any of claims 1-5, wherein, The heat insulation part is provided with a wire hole for passing a wire.

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