A kind of 3 Ultra-low temperature vacuum sample holder for He refrigerator

Abstract

The present invention provides a method for 3 The ultra-low temperature vacuum sample holder of the He refrigerator comprises: a sliding main unit; a vacuum chamber unit comprising: an outer tube, a vacuum chamber formed in the outer tube, a first vacuum extraction port for evacuating the vacuum chamber, and a first vacuum extraction port provided at one end of the vacuum chamber unit for contacting with the first vacuum extraction port. 3 The assembly comprises a vacuum connection flange secured to the valve interface of the He refrigerator; a lower support rod and sample holder assembly, comprising: a lower support rod disposed within the vacuum chamber along the longitudinal axis of the vacuum chamber unit; and a sample holder disposed at one end of the lower support rod proximate the vacuum connection flange. The other end of a sliding main pipe unit extends into the vacuum chamber unit and communicates with the vacuum chamber unit, ensuring an airtight connection between the sliding main pipe unit and the vacuum chamber unit. The other end of the lower support rod is secured to the other end of the sliding main pipe unit, and the sliding main pipe unit is configured to move in a piston-like manner within the vacuum chamber unit, thereby driving the lower support rod and sample holder to move axially along the vacuum chamber unit.

Description

Technical Field

[0001] The present invention generally relates to the technical field of ultra-low temperature physics research equipment, and in particular to a method for 3 Ultra-low temperature vacuum sample holder for He refrigerator. Background Art

[0002] With the deepening of condensed matter physics research, more and more quantum effects have been discovered by researchers, such as the quantum Hall effect. Furthermore, the discovery of two-dimensional graphene has made the study of new two-dimensional materials a hot topic. The emergence of two-dimensional superconductivity, two-dimensional magnetism, and slip ferroelectricity has opened up new physics research topics. For these novel quantum research fields, ultra-low temperature precision electrical transport is the best research method for related topics and an indispensable experimental technique in the field of cutting-edge condensed matter research. However, the development of ultra-low temperature scientific research equipment in China is still relatively slow, and there is an urgent need to develop ultra-low temperature vacuum sample rods, especially ultra-low temperature vacuum precision electrical transport measurement sample rods, to supplement the equipment shortage in related fields. Summary of the Invention

[0003] In view of the above problems, the present invention proposes a method for overcoming the above problems or at least partially solving the above problems. 3 Ultra-low temperature vacuum sample holder for He refrigerator.

[0004] One object of the present invention is to provide a 3 The ultra-low temperature vacuum sample holder of the He refrigerator can ensure the vacuum inside the sample holder to ensure 3 And the normal operation of the refrigerator.

[0005] A further object of the present invention is to eliminate the influence of minute air leakage generated through the sliding portion when the sliding main body unit slides.

[0006] Another further object of the present invention is to improve the effectiveness of the sample rod in performing precise electrical transport measurements.

[0007] In particular, the present invention provides a method for 3 Ultra-low temperature vacuum sample holder for He refrigerator, including:

[0008] a sliding main unit having one end sealed by a closure member;

[0009] A vacuum chamber unit comprising:

[0010] External control;

[0011] a vacuum cavity formed in the outer tube;

[0012] A first vacuum extraction port, used to evacuate the vacuum cavity; and

[0013] The vacuum connection flange is provided at one end of the vacuum chamber unit and is used to connect 3 He refrigerator valve interface fixed; and

[0014] The lower support rod and sample holder assembly is disposed in the vacuum chamber and includes:

[0015] a lower support rod, disposed in the vacuum chamber along the longitudinal axis of the vacuum chamber unit; and

[0016] The sample holder is arranged at one end of the lower support rod close to the vacuum connection flange, and the lower support rod, the sample holder and the vacuum chamber unit form an inner and outer nested structure;

[0017] The other end of the sliding main pipe unit extends into the vacuum chamber unit and communicates with the vacuum chamber body in a manner that the sliding main pipe unit and the vacuum chamber unit are airtightly connected. The other end of the lower support rod is fixed to the other end of the sliding main pipe unit, and the sliding main pipe unit is configured to be able to move like a piston inside the vacuum chamber unit to drive the lower support rod and the sample holder to move along the longitudinal axis of the vacuum chamber unit.

[0018] Optionally, the vacuum chamber unit further includes:

[0019] a vacuum isolation chamber formed at the other end of the vacuum chamber unit;

[0020] The outer wall of the sliding main unit passes through the vacuum isolation chamber and forms a tight fit with the vacuum isolation chamber, so that the sliding main unit can move airtightly along the longitudinal axis of the vacuum chamber unit;

[0021] The vacuum isolation chamber is provided with a second vacuum extraction port for evacuating the vacuum isolation chamber.

[0022] Optionally, the vacuum isolation chamber includes:

[0023] a top ring cover disposed at the end of the other end of the vacuum chamber unit; and

[0024] a bottom annular seal spaced apart from the top annular cover in the longitudinal direction of the outer tube and fixed to the outer tube by welding, wherein the top annular cover, the bottom annular seal and the outer tube enclose a vacuum isolation chamber;

[0025] The vacuum isolation chamber also includes:

[0026] a support block filling a space between the top ring cover, the bottom annular seal, the outer tube, and an outer wall of the sliding main tube unit, the top ring cover being fixed to the support block by a first fastener; and

[0027] Two O-rings are arranged on the inner surface of the outer wall of the support block facing the sliding main unit in a manner spaced apart from each other along the longitudinal direction of the outer tube. The outer wall of the sliding main unit is covered by the O-rings to form a tight fit.

[0028] Optionally, the sliding main tube unit includes a connecting tube with a hole fixed at the other end thereof, so that the interior of the sliding main tube unit is in communication with the vacuum chamber through the hole;

[0029] The other end of the lower support rod is provided with a connecting flange;

[0030] The perforated connecting pipe and the connecting flange are connected via a second fastener.

[0031] Optionally, the ultra-low temperature vacuum sample holder further comprises:

[0032] an upper support rod, disposed inside the sliding main body unit along the longitudinal axis of the sliding main body unit to form an inner-outer nested structure with the sliding main body unit; and

[0033] One or more radiation-proof supporting metal sheets are arranged along the longitudinal direction of the upper supporting rod and are used to position the upper supporting rod in the sliding main unit.

[0034] Optionally, the cryogenic vacuum sample holder further includes a head wiring unit as the closing element, which includes:

[0035] a lead interface for leading out measurement leads from the sample holder and passing through the interior of the vacuum chamber unit and the sliding main unit so as to be connected to an external measurement device; and

[0036] A seal is used to seal the lead interface.

[0037] Optionally, the head wiring unit further includes:

[0038] a head body, wherein the lead interface is provided on the head body; and

[0039] a top cover plate connected to the head body by a third fastener;

[0040] A fixing ring is provided at one end of the sliding main unit;

[0041] The head body is airtightly fixed to the fixing ring by a fourth fastener so that the head wiring unit seals the sliding main body unit as a closing element, and the interior of the head wiring unit is evacuated through the interior of the sliding main body unit via the vacuum chamber unit;

[0042] A support rod fixing groove is also provided in the head body, which is configured to allow one end of the upper support rod to be inserted therein to fix the upper support rod.

[0043] Optionally, the lower support rod and sample holder assembly further comprises:

[0044] One or more radiation-proof metal sheets are arranged in the vacuum chamber unit along the longitudinal direction of the lower support rod;

[0045] The heat sink metal flange is arranged in the vacuum chamber and penetrates the lower support rod, and is configured to utilize 3 The cooling capacity provided by the specific cooling part of the He refrigerator cools the measuring lead; and

[0046] One or more wiring troughs are provided near the heat sink metal flange or at other locations in the vacuum chamber for guiding or transferring the measuring leads, wherein the measuring leads are coupled to the heat sink metal flange via or without the wiring troughs.

[0047] Optionally, the lower support rod and sample holder assembly further comprises:

[0048] One or more heat-insulating filling blocks are disposed in the vacuum chamber and on the lower support rod passing between the heat sink metal flange and the sample holder; and

[0049] The filter is arranged in the vacuum cavity and located between the heat sink metal flange and the sample holder, and is connected to the measuring lead for filtering the signal transmitted by the measuring lead.

[0050] Optionally, the outer tube of the vacuum chamber unit and the sliding main tube unit are made of thin-walled metal tubes;

[0051] The measuring leads include leads with various functions, and the lead with each function is wrapped by a metal braided mesh.

[0052] The present invention provides 3 The ultra-low temperature vacuum sample holder of the He refrigerator is a long rod-shaped entity formed by a sliding main unit and a vacuum chamber unit. The lower support rod and the sample holder are nested inside the vacuum chamber unit. When in use, the vacuum chamber unit is fixed to the vacuum chamber unit through a vacuum connection flange. 3 The upper valve interface of the He refrigerator, the sliding main unit moves up and down like a piston inside the vacuum chamber unit, driving the lower support rod and the sample holder to move up and down, thereby achieving the sample holder in 3 The He refrigerator is transferred from the room temperature end to the low temperature end. The vacuum chamber is evacuated through the first vacuum port to ensure the vacuum inside the vacuum chamber and the sliding main unit connected to the gas, avoiding 3 Other gases enter the He refrigerator, thus ensuring good 3 And the normal operation of the refrigerator.

[0053] Furthermore, the vacuum chamber unit of the cryogenic vacuum sample holder provided by the present invention is equipped with a vacuum isolation chamber at one end near the sliding main unit, and a second vacuum evacuation port is provided in the vacuum isolation chamber. The outer wall of the sliding main unit passes through the vacuum isolation chamber and forms a tight fit with the two O-rings in the vacuum isolation chamber. This configuration ensures that when the sliding main unit slides while refrigerant gas is present within the vacuum chamber unit, any trace gas leakage generated through the sliding area can be evacuated within the vacuum isolation chamber.

[0054] Furthermore, in the ultra-low temperature vacuum sample holder provided by the present invention, the vacuum chamber unit is used for 3 The refrigeration adsorption pump of the He refrigerator structure and the 1K cell refrigeration part provide specific positions corresponding to the cooling power parts, and corresponding heat sink metal flanges are set. The measurement leads drawn down from room temperature are cooled by thermal contact, which reduces system heat leakage and thermal noise.

[0055] Furthermore, the outer tube of the vacuum chamber unit and the main sliding tube unit are both constructed from thin-walled metal tubes, ensuring that the measurement leads are effectively shielded from external electromagnetic noise throughout the metal tubes of the main sliding tube unit and the vacuum chamber unit. Furthermore, a metal braided mesh can be used to provide electromagnetic shielding isolation between measurement leads with different functions (for example, those for large-signal power circuits and precision small-signal measurement circuits). This ensures the conditions for performing precision electrical transport measurements within the cryogenic vacuum sample holder, thereby enhancing the effectiveness of these measurements.

[0056] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below.

[0057] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0059] Figure 1 Schematic diagram of the overall structure of a cryogenic vacuum sample holder according to one embodiment of the present invention;

[0060] Figure 2is a schematic perspective view of a three-dimensional model of a cryogenic vacuum sample holder according to an embodiment of the present invention;

[0061] Figure 3 for Figure 1 An enlarged schematic diagram of the head wiring unit of the ultra-low temperature vacuum sample holder is shown;

[0062] Figure 4 for Figure 1 A partially enlarged schematic diagram of the upper support rod and the sliding main unit of the ultra-low temperature vacuum sample holder is shown;

[0063] Figure 5 for Figure 1 An enlarged schematic diagram of a portion of the sliding main unit of the ultra-low temperature vacuum sample holder, the vacuum chamber unit, the lower support rod, and the sample holder assembly is shown;

[0064] Figure 6 FIG. 1 is a schematic structural diagram of a vacuum isolation chamber of a cryogenic vacuum sample holder according to an embodiment of the present invention. DETAILED DESCRIPTION

[0065] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0066] In order to solve the above technical problems, the embodiment of the present invention provides a method for 3 Ultra-low temperature vacuum sample holder for He refrigerator.

[0067] The extremely low temperature in this article may refer to a temperature below 4.2K, such as 1.2K or even 0.3K.

[0068] Figure 1 This is a schematic diagram of the overall structure of a cryogenic vacuum sample holder 100 according to an embodiment of the present invention. Figure 2 FIG. 1 is a schematic three-dimensional perspective view of a cryogenic vacuum sample holder 100 according to an embodiment of the present invention.

[0069] Figure 3 for Figure 1 The enlarged schematic diagram of the head wiring unit 140 of the cryogenic vacuum sample holder 100 is shown. Figure 4 for Figure 1 The upper support rod 112 and the sliding main unit 110 of the ultra-low temperature vacuum sample holder 100 are partially enlarged. Figure 5 for Figure 1FIG. 1 is an enlarged schematic diagram of a portion of the sliding main unit 110 of the cryogenic vacuum sample holder 100 , the vacuum chamber unit 120 , the lower support rod, and the sample holder assembly 130 . Figure 6 FIG. 1 is a schematic structural diagram of the vacuum isolation chamber 125 of the cryogenic vacuum sample holder 100 according to an embodiment of the present invention.

[0070] See also Figure 1 and Figure 2 As shown, in one embodiment, the cryogenic vacuum sample holder 100 of the present invention generally includes a sliding main tube unit 110, a vacuum chamber unit 120, and a lower support rod and sample holder assembly 130. One end of the sliding main tube unit 110 (also referred to as the top end of the sliding main tube unit 110) is sealed by a sealing element. The various components of the cryogenic vacuum sample holder 100 are described in detail below with reference to the accompanying drawings.

[0071] See also Figure 1 and Figure 5 As shown, in some embodiments, the vacuum chamber unit 120 includes: an outer tube 121; a vacuum chamber 122 formed in the outer tube 121; a first vacuum extraction port 123 for evacuating the vacuum chamber 122; and a vacuum connection flange 124 provided at one end of the vacuum chamber unit 120 (also referred to as the bottom end of the vacuum chamber unit 120) for connecting with the vacuum chamber unit 120. 3 The valve interface of the He refrigerator is fixed. The lower support rod and sample holder assembly 130 is disposed within the vacuum chamber 122 of the vacuum chamber unit 120. It includes a lower support rod 131 disposed within the vacuum chamber 122 along the longitudinal axis of the vacuum chamber unit 120; and a sample holder 132 disposed at one end of the lower support rod 131 near the vacuum connection flange 124 (also referred to as the bottom end of the lower support rod 131). The lower support rod 131 and sample holder 132 form a nested structure within the vacuum chamber unit 120.

[0072] The other end of the sliding main tube unit 110 (also referred to as the bottom end of the sliding main tube unit 110) extends from the other end (also referred to as the top end of the vacuum chamber unit 120) into the vacuum chamber unit 120 and communicates with the vacuum chamber body 122, such that the sliding main tube unit 110 and the vacuum chamber unit 120 are airtightly connected. The other end of the lower support rod 131 (also referred to as the top end of the lower support rod 131) is fixed to the other end of the sliding main tube unit 110. The sliding main tube unit 110 is configured to move in a piston-like manner within the vacuum chamber unit 120, thereby driving the lower support rod 131 and the sample holder 132 to move along the longitudinal axis of the vacuum chamber unit 120. Since the other end of the sliding main tube unit 110 is in airtight communication with the vacuum chamber body 122 of the vacuum chamber unit 120, the interior of the sliding main tube unit 110 can be evacuated via the vacuum chamber unit 120.

[0073] The embodiment of the present invention provides a 3 The He cryogenic vacuum sample holder 100 is composed of a sliding main unit 110 and a vacuum chamber unit 120 to form a long rod-shaped entity. The lower support rod 131 and the sample holder 132 are arranged inside the vacuum chamber unit 120 in an inner and outer nested manner. When in use, the vacuum chamber unit 120 is fixed to the vacuum chamber unit 120 by a vacuum connection flange 124. 3 The upper valve interface of the He refrigerator is connected, and the sliding main unit 110 moves up and down like a piston inside the vacuum chamber unit 120 to drive the lower support rod 131 and the sample holder 132 to move up and down, thereby realizing the sample holder 132 3 The He refrigerator is transferred from the room temperature end to the low temperature end. The vacuum chamber 122 is evacuated through the first vacuum port 123 to ensure the vacuum inside the vacuum chamber 122 and the sliding main unit 110 connected to the gas, thereby avoiding 3 Other gases enter the He refrigerator, thus ensuring good 3 And the normal operation of the refrigerator.

[0074] In some embodiments, the lower support rod 131 may be composed of multiple, for example, two to three, thin-walled metal tubes (e.g., stainless steel tubes). These metal tubes may be evenly arranged around the central axis of the outer tube 121 of the vacuum chamber unit 120. For example, two metal tubes may be arranged symmetrically around the center; three metal tubes may be arranged in an equilateral triangle.

[0075] Continue to see Figure 1 and Figure 5 In some embodiments, the vacuum chamber unit 120 may further include a vacuum isolation chamber 125 formed at the other end of the vacuum chamber unit 120. The outer wall of the sliding main tube unit 110 passes through the vacuum isolation chamber 125 and forms a tight fit therewith, allowing the sliding main tube unit 110 to move airtightly along the longitudinal axis of the vacuum chamber unit 120. The vacuum isolation chamber 125 is also provided with a second vacuum port 127 for evacuating the vacuum isolation chamber 125.

[0076] See also Figure 6 As shown, in some embodiments, the vacuum isolation chamber 125 includes: a top annular cover 1251, which is disposed at the end of the other end of the vacuum chamber unit 120; and a bottom annular seal 1252, which is spaced apart from the top annular cover 1251 along the longitudinal direction of the outer tube 121 and fixed to the outer tube 121 by welding. The top annular cover 1251, the bottom annular seal 1252 and the outer tube 121 enclose a vacuum isolation chamber 125.

[0077] The vacuum isolation chamber 125 may further include a support block 1253, which fills the space between the top annular cover 1251, the bottom annular seal 1252, the outer tube 121, and the outer wall of the sliding main tube unit 110 (i.e., the inner vacuum chamber 1255). This leaves an axial cylindrical area in the center of the support block 1253 for the sliding main tube unit 110 to slide. The top annular cover 1251 is secured to the support block 1253 by a first fastener (e.g., a screw). The sliding main tube unit 110 slides through the center hole of the top annular cover 1251, the axial cylindrical area of ​​the support block 1253, and the center hole of the bottom annular seal 1252. The material of the support block 1253 can be, for example, polytetrafluoroethylene.

[0078] The vacuum isolation chamber 125 may also include two O-rings 1254, spaced longitudinally along the outer tube 121, disposed on the inner surface of the outer wall of the support block 1253 facing the sliding main tube unit 110. The O-rings 1254 enclose the outer wall of the sliding main tube unit 110, creating a tight fit. This allows the gap between the support block 1253 and the sliding main tube unit 110 to be evacuated via the second vacuum port 127 and sealed by the two O-rings 1254, thereby ensuring that any air leakage generated during the sliding process is promptly removed.

[0079] In some embodiments, the support block 1253 may include multiple sub-support blocks 1253 closely arranged along the axial direction of the outer tube 121, and each O-ring 1254 may be embedded in a gap between two sub-support blocks 1253, with the O-ring 1254 partially protruding from the inner surface of the outer wall of the support block 1253 facing the sliding main tube unit 110. In other alternative embodiments, two corresponding grooves may be formed on the inner surface of the outer wall of the support block 1253 facing the sliding main tube unit 110, and two O-rings 1254 may be respectively installed in the two grooves, with the O-rings 1254 partially protruding from the inner surface of the outer wall of the support block 1253 facing the sliding main tube unit 110.

[0080] The vacuum chamber unit 120 of the cryogenic vacuum sample holder 100 provided in this embodiment of the present invention is provided with a vacuum isolation chamber 125 at one end near the sliding main tube unit 110, and a second vacuum evacuation port 127 is provided on the vacuum isolation chamber 125. The outer wall of the sliding main tube unit 110 passes through the vacuum isolation chamber 125 and forms a tight fit with two O-rings 1254 in the vacuum isolation chamber 125. This configuration ensures that when refrigerant gas is present within the vacuum chamber unit 120 and the sliding main tube unit 110 slides, any trace gas leakage generated through the sliding area can be evacuated within the vacuum isolation chamber 125, preventing external gas from entering the vacuum chamber 122 of the vacuum chamber unit 120 and interfering with refrigeration.

[0081] Continue to see Figure 5 In some embodiments, the sliding main tube unit 110 includes a perforated connecting tube 111 fixed (e.g., by welding) at its other end (i.e., the bottom end), such that the interior of the sliding main tube unit 110 communicates with the vacuum chamber 122 of the vacuum chamber unit 120 through the holes in the perforated connecting tube 111. The holes can be distributed on the peripheral wall or the bottom wall of the perforated connecting tube 111.

[0082] The other end (i.e., top end) of the lower support rod 131 may be provided with a connecting flange 133. The perforated connecting pipe 111 and the connecting flange 133 may be connected by a second fastener (e.g., a screw) to achieve a fixed connection between the lower support rod 131 and the sliding main unit 110.

[0083] See also Figure 1 and Figure 4 As shown, in some embodiments, the cryogenic vacuum sample holder 100 may further include an upper support rod 112. The upper support rod 112 is disposed within the sliding main body unit 110 along the longitudinal axis of the sliding main body unit 110, forming an inner-outer nested structure with the sliding main body unit 110. The upper support rod 112 may be composed of multiple, for example, three, thin-walled metal tubes (e.g., stainless steel tubes). These metal tubes may be evenly arranged around the central axis of the sliding main body unit 110. For example, the three metal tubes may be arranged in an equilateral triangle.

[0084] Optionally, the cryogenic vacuum sample holder 100 may further include one or more radiation-proof supporting metal sheets 113 arranged longitudinally along the upper supporting rod 112 for positioning the upper supporting rod 112 in the sliding main unit 110. The metal sheets may be steel sheets, for example.

[0085] See also Figure 1 and Figure 3 In some embodiments, the cryogenic vacuum sample holder 100 may further include a head wiring unit 140. The head wiring unit 140 includes: a lead interface 141 for leading out measurement leads (such as cryogenic measurement leads) from the sample holder 132 and passing through the interior of the vacuum chamber unit 120 and the sliding main unit 110 to connect to external measurement equipment; and a seal (not shown in the figure) for sealing the lead interface 141. The lead interface 141 can be customized according to the actual vacuum sealing joint used. The seal can be an O-ring that matches a threaded cap to seal the lead interface 141.

[0086] Continue to see Figure 3In some embodiments, the header wiring unit 140 may further include: a header body 142, on which the lead interface 141 is disposed; and a top cover 143 connected to the header body 142 via a third fastener (e.g., a screw). The connection between the top cover 143 and the header body 142 may also be sealed by a sealing element (e.g., an O-ring, not shown).

[0087] Furthermore, a fixing ring 114 is provided (e.g., by welding) at one end (i.e., the top end) of the sliding main body unit 110. The head body 142 is airtightly fixed to the fixing ring 114 of the sliding main body unit 110 via a fourth fastener (e.g., a jackscrew), allowing the head wiring unit 140 to act as a sealing element to seal the sliding main body unit 110, and the interior of the head wiring unit 140 can be evacuated from the interior of the sliding main body unit 110 via the vacuum chamber unit 120. Specifically, the airtight fixation between the head body 142 and the sliding main body unit 110 is achieved using a seal 115, which can be an O-ring and is disposed within a groove reserved in the head body 142 and / or the fixing ring 114.

[0088] In some embodiments, a support rod fixing groove 144 is further provided in the head body 142 of the sliding main unit 110, which is configured to allow one end of the upper support rod 112 to be inserted therein to fix the upper support rod 112, thereby achieving convenient and accurate positioning of the upper support rod 112.

[0089] See also Figure 1 and Figure 5 As shown, in some embodiments, the lower support rod and sample holder assembly 130 may further include one or more radiation shielding metal sheets 134 arranged in the vacuum chamber unit 120 along the longitudinal direction of the lower support rod 131. The metal sheet may be, for example, a steel sheet.

[0090] In some embodiments, the lower support rod and sample holder assembly 130 may further include a heat sink metal flange 135 disposed in the vacuum chamber 122 and passing through the lower support rod 131, configured to utilize 3 The cooling capacity provided by the specific cooling part of the He refrigerator cools the measuring lead. 3 The specific refrigeration part of the He refrigerator may be a refrigeration adsorption pump, a 1K cell refrigeration part, etc. The heat sink metal flange 135 may be made of a metal with good thermal conductivity, such as copper.

[0091] In this embodiment, the vacuum chamber unit 120 is used to 3The specific positions corresponding to the cooling power parts provided by the refrigeration adsorption pump and the 1K cell refrigeration part of the He refrigerator structure are provided with corresponding heat sink metal flanges 135, and the measurement leads drawn down from room temperature are cooled by thermal contact, thereby reducing the heat leakage of the system and the thermal noise, and providing conditions for precise low-temperature measurement.

[0092] In some embodiments, the lower support rod and sample holder assembly 130 may further include one or more wiring grooves 136 disposed near the heat sink metal flange 135 or at other locations within the vacuum chamber 122 for guiding or transferring measurement leads, wherein the measurement leads are coupled to the heat sink metal flange 135 via or without the wiring grooves 136 .

[0093] Specifically, according to the specific situation of the measurement lead connection, a wiring groove 136 is configured near the heat sink metal flange 135, and the measurement lead is coupled to the heat sink metal flange 135 by the wiring groove 136, or the wiring groove 136 is not used for connection, and the lead is directly coupled to the copper flange, and the radiation-proof metal sheet 134 is used to fix the lower support rod 131 at the remaining positions.

[0094] Continue to see Figure 1 and Figure 5 In some embodiments, the lower support rod and sample holder assembly 130 may further include: one or more heat-insulating filling blocks 137, which are disposed in the vacuum chamber 122 and pass through the lower support rod 131 between the heat sink metal flange 135 and the sample holder 132. The heat-insulating filling blocks 137 may be made of polymer materials. By disposing the heat-insulating filling blocks 137 between the heat sink metal flange 135 and the low-temperature sample holder 132, the 3 Heat leakage ensures the cooling effect.

[0095] In some embodiments, the lower support rod and sample holder assembly 130 may further include a filter 138 disposed in the vacuum chamber 122 and located between the heat sink metal flange 135 and the sample holder 132 , and connected to the measurement lead for filtering the signal transmitted by the measurement lead.

[0096] The measurement leads can be constructed from multiple segments of low-temperature twisted-pair cable, extending from the lead interface 141 at the head of the sample holder 100 to the low-temperature sample holder 132 at the bottom. Heat sinking in key cooling components (such as the refrigerated adsorption pump and 1K cell) and the addition of a low-temperature filter 138 can provide excellent, precise low-temperature measurements.

[0097] In some embodiments, the outer tube 121 of the vacuum chamber unit 120 and the sliding main tube unit 110 are made of thin-walled metal tubes (e.g., stainless steel tubes). Since the measurement leads are completely inside the metal tubes of the sliding main tube unit 110 and the vacuum chamber unit 120, they can be effectively shielded from external electromagnetic noise.

[0098] Optionally, in some embodiments, the measurement leads include multiple leads with different functions, and each lead with a function is wrapped in a metal braided mesh (not shown). The metal braided mesh provides electromagnetic shielding isolation between the measurement leads with different functions (e.g., the leads for a large signal power circuit and a precision small signal measurement circuit).

[0099] Through the above configuration, the conditions for the ultra-low temperature vacuum sample holder 100 to perform precise electrical transport measurements can be guaranteed, thereby improving the effect of the sample holder 100 performing precise electrical transport measurements.

[0100] The following combination Figure 1 The illustrated embodiment specifically illustrates the structure and working method of the cryogenic vacuum sample holder 100 of the present invention.

[0101] The sample rod 100 includes multiple units and inner and outer nested structures. The vacuum chamber unit 120 will be fixed to the refrigerator through the vacuum connection flange 124 and remain stationary. The head wiring unit 140, the upper and lower support rods 131 and the sliding main pipe unit 110 are integrated through a variety of fixing methods, including: the head wiring unit 140 is fixed to the sliding main pipe unit 110 through the main pipe fixing ring 114 with a top screw; the upper support rod 112 is fixed to the head wiring unit 140 through the support rod fixing groove 144 inside the head body 142 with a screw; the sliding main pipe unit 110 is fixed to the lower support rod 131 through the perforated connecting tube 111 and the connecting flange 133 with a top screw. The long rod-like entity formed in this way can allow the sliding main pipe unit 110 to move like a piston inside the vacuum chamber unit 120, thereby realizing the low-temperature sample holder 132 3 The vacuum chamber unit 120 is fixed to the room temperature end of the He refrigerator through the vacuum connection flange 124. 3 The upper valve interface of the He refrigerator can be used to perform vacuuming operation through the first vacuum port 123 and the second vacuum port 127 to ensure the vacuum inside the vacuum chamber 122 and the sliding main unit 110 that can be ventilated therewith, thereby avoiding 3 The double O-ring vacuum isolation chamber 125 ensures that when there is refrigerant gas inside the vacuum chamber unit 120 and the sliding main unit 110 slides, the trace gas leakage generated through the sliding part can be extracted in the isolation chamber.

[0102] During operation, the chip to be tested is first inserted into the matching low-temperature sample holder 132, and the internal low-temperature measurement lead is introduced into the head wiring unit 140 and led out from the corresponding lead interface 141, and then connected to the measurement equipment through the external measurement line. Then, a clamp is used to clamp the sliding main unit 110 on the upper part of the double O-ring vacuum isolation chamber 125 to prevent it from sliding relative to the vacuum chamber unit 120, and then the sample holder 100 is fixed to the vacuum connection flange 124. 3 Open the upper interface of the He refrigerator, keeping the refrigerator interface valve closed, and evacuate the vacuum chamber unit 120 and the vacuum isolation chamber 125 through the first and second vacuum interfaces. Once the vacuum reaches the required value for the refrigerator system, stop evacuating the vacuum chamber 122 while maintaining the vacuum isolation chamber 125. Open the refrigerator interface valve, release the sliding main pipe unit 110, and slowly slide it deeper into the refrigerator until the low-temperature sample holder 132 reaches the low-temperature end. At this point, the head connection unit 140 has just reached the top of the vacuum chamber unit 120, preventing the sliding main pipe unit 110 from sliding further downward. Vacuuming the vacuum isolation chamber 125 is also stopped, and the low-temperature measurement experiment can then be carried out. Finally, after the measurement is completed, re-evacuate the vacuum isolation chamber 125, allowing the sliding main pipe unit 110 to slowly slide back to the room temperature end. Close the refrigerator interface valve, and after the sample holder 100 has fully warmed up, disconnect the sample holder 100 from the refrigerator and retrieve the sample.

[0103] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0104] At this point, those skilled in the art will recognize that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications consistent with the principles of the present invention may be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims

1. A method for 3 Ultra-low temperature vacuum sample holder for He refrigerator, including: a sliding main unit having one end sealed by a closure member; A vacuum chamber unit comprising: External control; a vacuum cavity formed in the outer tube; A first vacuum port, used for evacuating the vacuum cavity; and The vacuum connection flange is provided at one end of the vacuum chamber unit and is used to connect with the 3 He refrigerator valve interface fixed; and The lower support rod and sample holder assembly is disposed in the vacuum chamber and includes: a lower support rod, disposed in the vacuum chamber along the longitudinal axis of the vacuum chamber unit; and A sample holder is provided at one end of the lower support rod close to the vacuum connection flange, wherein the lower support rod, the sample holder and the vacuum chamber unit form an inner-outer nested structure; The other end of the sliding main pipe unit extends into the vacuum chamber unit and communicates with the vacuum chamber body in a manner that the sliding main pipe unit is airtightly connected to the vacuum chamber unit. The other end of the lower support rod is fixed to the other end of the sliding main pipe unit, and the sliding main pipe unit is configured to be able to move in a piston-like manner inside the vacuum chamber unit to drive the lower support rod and the sample holder to move along the longitudinal axis of the vacuum chamber unit.

2. The cryogenic vacuum sample holder according to claim 1, wherein: The vacuum chamber unit further includes: a vacuum isolation chamber formed at the other end of the vacuum chamber unit; The outer wall of the sliding main unit passes through the vacuum isolation chamber and forms a tight fit with the vacuum isolation chamber, so that the sliding main unit can move airtightly along the longitudinal axis of the vacuum chamber unit; The vacuum isolation chamber is provided with a second vacuum extraction port for evacuating the vacuum isolation chamber.

3. The cryogenic vacuum sample holder according to claim 2, wherein: The vacuum isolation chamber comprises: a top ring cover, disposed at the distal end of the other end of the vacuum chamber unit; and a bottom annular seal, spaced apart from the top annular cover along the longitudinal direction of the outer tube and fixed to the outer tube by welding, wherein the top annular cover, the bottom annular seal and the outer tube enclose the vacuum isolation chamber; The vacuum isolation chamber further comprises: a support block filling a space between the top ring cover, the bottom annular seal, the outer tube, and an outer wall of the sliding main tube unit, the top ring cover being fixed to the support block by a first fastener; and Two O-rings are arranged on the inner surface of the outer wall of the support block facing the sliding main unit in a manner of being spaced apart from each other in the longitudinal direction of the outer tube. The outer wall of the sliding main unit is covered by the O-rings to form a tight fit.

4. The cryogenic vacuum sample holder according to claim 1, wherein: The sliding main pipe unit includes a connecting pipe with a hole fixed at the other end thereof, so that the interior of the sliding main pipe unit is connected to the vacuum chamber through the hole; The other end of the lower support rod is provided with a connecting flange; The perforated connecting pipe is connected to the connecting flange via a second fastener.

5. The cryogenic vacuum sample holder according to claim 1 , further comprising: an upper support rod, arranged inside the sliding main unit along the longitudinal axis of the sliding main unit, so as to form an inner-outer nested structure with the sliding main unit; as well as One or more radiation-proof supporting metal sheets are arranged along the longitudinal direction of the upper supporting rod and are used to position the upper supporting rod in the sliding main unit.

6. The cryogenic vacuum sample holder according to claim 5, further comprising a head wiring unit as the closing element, comprising: A lead interface, used for leading out a measurement lead from the sample holder and passing through the interior of the vacuum chamber unit and the sliding main unit to connect to an external measurement device; as well as A sealing member is used to seal the lead interface.

7. The cryogenic vacuum sample holder according to claim 6, wherein: The head wiring unit also includes: a head body, the lead interface being arranged on the head body; and a top cover plate connected to the head body via a third fastener; The one end of the sliding main unit is provided with a fixing ring; The head body is airtightly fixed to the fixing ring by a fourth fastener, so that the head wiring unit seals the sliding main body unit as the closing element, and the interior of the head wiring unit is evacuated through the interior of the sliding main body unit via the vacuum chamber unit; The head body is also provided with a support rod fixing groove, which is configured to allow one end of the upper support rod to be inserted therein to fix the upper support rod.

8. The cryogenic vacuum sample holder according to claim 6, wherein: The lower support rod and sample holder assembly further comprises: One or more radiation-proof metal sheets are arranged in the vacuum chamber unit along the longitudinal direction of the lower support rod; The heat sink metal flange is arranged in the vacuum chamber and penetrates the lower support rod, and is configured to utilize the 3 The specific refrigeration part of the He refrigerator provides cooling capacity to cool the measuring lead; and One or more wiring troughs are provided near the heat sink metal flange or at other locations in the vacuum chamber for guiding or transferring the measuring leads, wherein the measuring leads are coupled to the heat sink metal flange via or without the wiring troughs.

9. The cryogenic vacuum sample holder according to claim 8, wherein: The lower support rod and sample holder assembly further comprises: One or more heat-insulating filling blocks are disposed in the vacuum chamber and pass through the lower support rod between the heat sink metal flange and the sample holder; and The filter is arranged in the vacuum chamber and located between the heat sink metal flange and the sample holder, and is connected to the measuring lead, and is used for filtering the signal transmitted by the measuring lead.

10. The cryogenic vacuum sample holder according to claim 6, wherein: The outer tube of the vacuum chamber unit and the sliding main tube unit are made of thin-walled metal tubes; The measuring leads include leads with multiple functions, and each lead with a function is wrapped by a metal braided mesh.

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