A precision measurement platform for displacement and force of thermal insulation support parts for superconducting cavities at extremely low temperatures

Abstract

The invention discloses a displacement and force precision measuring platform for an insulation support at extremely low temperature for a superconducting cavity, characterized in that it comprises a three-dimensional tester calibration installation platform (1), a measuring platform pillar (2), a measuring platform base (3), a calibration platform fine-tuning body (4) and a measuring platform outer cylinder (6); wherein the top of the measuring platform outer cylinder (6) is provided with a three-dimensional tester calibration installation platform (1); the bottom of the measuring platform outer cylinder (6) is connected to the measuring platform base (3) through the measuring platform pillar (2); the calibration platform fine-tuning body (4) is arranged inside the measuring platform outer cylinder (6); and the measuring platform base (3) is provided with a low-temperature heater element, a low-temperature temperature measuring element and a fixing installation hole for a prefabricated force transmission rod. The invention can ensure the measurement accuracy at extremely low temperature and provide a stable test platform at micrometer level at extremely low temperature for the tested object.

Description

Technical Field

[0001] The present invention relates to a displacement and force precision measuring platform for an insulating support for a superconducting cavity at an extremely low temperature, in particular to a precision measurement of force and displacement of an insulating support for a superconducting cavity configured with stainless steel and epoxy resin in an extremely low temperature environment, and belongs to the technical field of accelerator superconducting low temperature testing. Background Art

[0002] The superconducting cavity is an important device for particle acceleration in accelerators. It is mainly used to accelerate electrons, protons, etc. in the beam channel and regulate the beam. The superconducting cavity is made of Nb-Ti alloy material. This alloy material behaves as a conventional conductor at room temperature. When it is cooled to below -265℃, the superconducting cavity enters the superconducting state, becomes a superconductor, and enters its working mode. In order to maintain the superconducting state of the superconducting cavity, it needs to be placed inside a container filled with extremely low temperature liquid, which is called a cryostat. The cryostat is mainly composed of a vacuum chamber, a superconducting cavity helium pool, a superconducting cavity and its accessories, and an extremely low temperature insulation support. The superconducting cavity needs to be maintained in an extremely low temperature environment during operation, and the vacuum chamber of the cryostat is at room temperature. In order to maintain the stable operation of the superconducting cavity and energy saving and environmental protection, a composite material made of stainless steel and epoxy with low thermal conductivity is required as its support. The support made of this composite material can support a superconducting cavity helium pool weighing hundreds of kilograms inside the vacuum chamber of the cryostat. One end of the superconducting cavity insulation support is connected to the room temperature vacuum chamber wall of the cryostat, and the other end is connected to the helium pool of the superconducting cavity in an extremely low temperature environment. When the superconducting cavity is in stable operation, its position needs to be relatively stable, and the displacement amplitude is controlled within a few microns. The extremely low temperature support made of a composite material made of stainless steel and epoxy resin can provide better supporting force. At present, the low temperature mechanical properties of the superconducting cavity insulation material support can be tested by a tensile machine with a low temperature device, but the accuracy of its force and displacement measurement cannot meet the test requirements of the insulation support for the superconducting cavity cryostat at extremely low temperatures. The present invention can be used for the precise force and displacement measurement of the insulation support made of stainless steel and epoxy resin for the superconducting cavity cryostat in an extremely low temperature environment at -196°C. Summary of the invention

[0003] The purpose of the present invention is to provide a precision measurement platform for displacement and force of an insulating support for a superconducting cavity at an extremely low temperature, so as to solve the problem that the current dynamometer with a cryogenic device cannot meet the requirements for precise measurement of force and displacement under extremely low temperature test conditions, and cannot meet the test problem of measuring micron-level displacement in an ultra-low temperature environment at a 1:1 size of an insulating support actually used under a certain tension / pressure.

[0004] The technical solution adopted by the present invention is:

[0005] A displacement and force precision measuring platform for superconducting cavity insulation support at ultra-low temperature, characterized in that it comprises a three-dimensional tester calibration installation platform 1, a measuring platform support 2, a measuring platform base 3, a calibration platform fine-tuning body 4 and a measuring platform outer cylinder 6; wherein,

[0006] A three-dimensional tester calibration installation platform 1 is arranged on the top of the outer cylinder 6 of the measuring platform; the bottom of the outer cylinder 6 of the measuring platform is connected to the measuring platform base 3 through the measuring platform support 2;

[0007] The calibration platform fine-tuning body 4 is arranged inside the outer cylinder 6 of the measuring platform; the bottom of the calibration platform fine-tuning body 4 is a fine-tuning body base, a central cylinder is arranged on the fine-tuning body base, and a central cone is arranged on the central cylinder; the top of the central cone is in direct contact with the three-dimensional tester calibration mounting platform 1; the calibration platform fine-tuning body 4 is used to fine-tune the three-dimensional displacement of the three-dimensional tester calibration mounting platform 1;

[0008] The measuring platform base 3 is provided with fixing installation holes for the low-temperature heater element, the low-temperature temperature measuring element and the prefabricated force transmission rod; the measuring platform base 3 is used to connect with the low-temperature end of the superconducting cavity insulation support to be measured to transfer heat; the force at the low-temperature end of the superconducting cavity insulation support to be measured is transmitted to the dynamometer through the prefabricated force transmission rod, and the force data is transmitted to the data processing unit through the dynamometer; the displacement of the low-temperature end of the superconducting cavity insulation support to be measured is measured by the three-dimensional tester installed on the three-dimensional tester calibration installation platform 1 and transmitted to the data processing unit.

[0009] Furthermore, the central cone column is made of carbon fiber material by fixed mold manufacturing and then polished, and the fibers of the carbon fiber material are arranged horizontally during the fixed mold manufacturing.

[0010] Furthermore, the central cylinder is made of stainless steel, and a raised structure is provided at the bottom thereof; the fine-tuning main body base is made of stainless steel; the outer cylinder 6 of the measuring platform is made of stainless steel, and the three-dimensional tester calibration mounting platform 1 is made of carbon fiber.

[0011] Furthermore, the measuring platform support column 2 is made of a composite material of G10 glass fiber and resin.

[0012] Furthermore, the measuring platform support 2 is made of stainless steel.

[0013] Furthermore, a fine-tuning hole 5 is provided on the side of the outer cylinder 6 of the measuring table, which is used to adjust the position of the fine-tuning main body base through the fine-tuning hole 5, so as to realize the position calibration of the three-dimensional tester calibration mounting platform 1 before it is installed and fixed on the top of the outer cylinder 6 of the measuring table.

[0014] A method for measuring displacement and force of an insulating support member for a superconducting cavity at extremely low temperatures, the steps comprising:

[0015] 1) After the low-temperature end of the superconducting cavity composite insulation support to be tested is connected to the measuring platform base 3, the three-dimensional tester calibration installation platform 1 is pre-installed on the top of the measuring platform outer cylinder 6; wherein, the bottom of the measuring platform outer cylinder 6 is connected to the measuring platform base 3 through the measuring platform support 2; a calibration platform fine-tuning body 4 is arranged in the measuring platform outer cylinder 6; the bottom of the calibration platform fine-tuning body 4 is a fine-tuning body base, a central cylinder is arranged on the fine-tuning body base, and a central cone column is arranged on the central cylinder; the top of the central cone column is in direct contact with the three-dimensional tester calibration installation platform 1;

[0016] 2) The position of the base of the fine-tuning main body is adjusted through the fine-tuning hole 5 on the side of the outer cylinder 6 of the measuring platform, so as to realize the position calibration of the three-dimensional tester calibration mounting platform 1; then the three-dimensional displacement of the three-dimensional tester calibration mounting platform 1 is finely adjusted through the calibration platform fine-tuning main body 4, and then the three-dimensional tester calibration mounting platform 1 is installed on the top of the outer cylinder 6 of the measuring platform;

[0017] 3) According to the working temperature requirement of the calibration mounting platform 1 of the three-dimensional tester, the temperature of the measuring platform base 3 is controlled by the thermometer and the heater on the measuring platform base 3, thereby controlling the temperature of the measuring platform support 2;

[0018] 4) The force applied to the low-temperature end of the superconducting cavity insulation support member under test is transmitted to the dynamometer through the prefabricated force transmission rod on the measuring platform base 3, and the force data is transmitted to the data processing unit through the dynamometer; the displacement of the low-temperature end of the superconducting cavity insulation support member is measured by the three-dimensional tester installed on the three-dimensional tester calibration installation platform 1 and transmitted to the data processing unit.

[0019] The displacement and force precision measuring platform of the superconducting cavity insulation support at ultra-low temperature of the present invention comprises an ultra-low temperature micrometer displacement test platform and an ultra-low temperature force test piece. The ultra-low temperature micrometer displacement test platform is the table and foundation for measuring the micro displacement of the composite insulation support made of stainless steel and epoxy resin under ultra-low temperature conditions; the ultra-low temperature force test piece is placed on the base of the measuring platform, which can realize the force measurement and force conduction of the composite insulation support made of stainless steel and epoxy resin under ultra-low temperature conditions. The ultra-low temperature micron-level displacement test bench needs to be calibrated at room temperature and low temperature. The processing materials of the ultra-low temperature micron-level displacement test bench are composed of 316 stainless steel, stainless steel and carbon fiber. According to the distance from the calibration table fine-tuning column, the base and pillar of the measuring table are made of stainless steel, the bottom of the calibration table fine-tuning column is made of stainless steel, the upper end of the calibration table fine-tuning column is made of carbon fiber, the outer cylinder of the test bench is made of stainless steel, the mounting table of the three-dimensional calibrator is made of carbon fiber, and the bolts for fixing and positioning the base of the measuring table are made of 316 stainless steel; except for the calibration table fine-tuning column and the mounting table of the three-dimensional calibrator, which need to be molded and manually polished, the processing materials of other parts are processed and manufactured using traditional mechanical processes. The ultra-low temperature micron-level displacement test bench has extremely small displacement changes at extremely low temperatures. It is equipped with a precision three-dimensional tester that can work at extremely low temperatures to form an ultra-low temperature micron-level test device. The overall size of the test bench is 76mm in height, and the area occupied by the bottom is a circular area with a diameter of 90mm. The test bench is equipped with a low-temperature temperature sensor, a low-temperature heater, an insulating support calibration point, and a three-dimensional tester fixing fixture. The temperature sensor and the low-temperature heater transmit the temperature and current signals to the normal temperature signal interface through the connecting wire of the special sensor. The displacement signal collected by the three-dimensional tester transmits the optical signal to the normal temperature signal interface through a special optical fiber, and then is transmitted to the external processor by the normal temperature signal interface, so as to realize remote monitoring, reading, storage and display of tiny displacement signals under extremely low temperatures.

[0020] Compared with the prior art, the present invention has the following positive effects:

[0021] The ultra-low temperature displacement measuring platform described in the present invention works in a low temperature environment of -196℃-30℃, and the displacement measurement accuracy at ultra-low temperature is 1 to 10 microns; by arranging the ultra-low temperature displacement measuring platform at different positions of the measured object, multi-point simultaneous measurement can be achieved; it is made of materials such as 316 stainless steel, stainless steel and carbon fiber according to certain arrangement rules, and different materials have different expansion coefficients, rigidity and costs at ultra-low temperatures, which are used as processing materials for different parts of the ultra-low temperature displacement measuring platform, which can reduce the cost of the ultra-low temperature displacement measuring platform and ensure the measurement accuracy requirements. Among them, 316 stainless steel is used as the processing material of the measuring platform base 3 and the measuring platform outer cylinder 6. 316 stainless steel has low thermal conductivity at 80K temperature, but is cheap, easy to obtain and process, and the rigidity of the 316 material itself meets the force and heat transfer requirements of the ultra-low temperature displacement measuring platform. The thermal shrinkage of stainless steel at low temperature is much lower than that of 316 stainless steel. Using stainless steel as the processing material for the central cylinder of the calibration platform fine-tuning body 4 can maintain the micron-level measurement accuracy of extremely low temperature displacement measurement, and is easy to process using CNC machine tools, effectively reducing the calibration workload and processing difficulty of the measurement platform at low temperature; carbon fiber material is used as the central cone column of the calibration platform fine-tuning body 4, which is directly in contact with the three-dimensional calibration instrument installation platform 1. The thermal expansion coefficient of carbon fiber material at extremely low temperature is extremely low, and the bearing capacity in the longitudinal direction of carbon fiber is high. The central cone column of the calibration platform fine-tuning body 4 is processed with carbon fiber material. The longitudinal growth of carbon fiber material into fiber meets the normal temperature and low temperature fine-tuning calibration requirements of the extremely low temperature displacement measurement platform. The cone angle and cone top size of the central cone column of the calibration platform fine-tuning body 4 can be adjusted according to the processing material of the three-dimensional calibration instrument installation platform 1 to ensure the measurement accuracy at extremely low temperature. The extremely low temperature measurement platform is supplemented by a non-contact three-dimensional positioning instrument at extremely low temperature to provide a stable test platform at the micron level at extremely low temperature for the measured object.

[0022] The present invention fixes a prefabricated force transmission rod on the base of the measuring platform, so that the axial or tangential force applied to the composite insulation support for the superconducting cavity can be transmitted to the dynamometer at the room temperature end. By replacing the prefabricated rod, the insulation support made of stainless steel and epoxy resin of different sizes can be tested for axial force or tangential force at extremely low temperature.

[0023] The present invention adopts a modular structure, which is convenient for calibration of the test bench and placement of insulation supports of a certain size, and realizes real-time remote monitoring and display functions of displacement, temperature, force and heat received by the tested piece in a low temperature environment range of -196°C to 30°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 It is a left view of the present invention.

[0026] Figure 3 It is a schematic diagram of the cross-sectional structure of the present invention.

[0027] 1-3D tester calibration mounting table, 2-measuring table support, 3-measuring table base, 4-calibration table fine-tuning column, 5-horizontal direction fine-tuning hole, 6-measuring table outer cylinder. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings.

[0029] like Figure 1 The figure shows a superconducting cavity insulation support ultra-low temperature displacement and force precision measuring platform of the present invention, which is composed of a three-dimensional tester calibration installation platform 1, a measuring platform support 2, a measuring platform base 3, a calibration platform fine-tuning body 4, a fine-tuning hole 5, and a measuring platform outer cylinder 6. The inner layer of the measuring platform outer cylinder 6 is the calibration platform fine-tuning body 4, which includes a central cylinder, a central cone column and a fine-tuning body base, as shown in FIG. Figure 3 As shown, the central cone column presents a structure with a large bottom and a small top. It is made of carbon fiber material and then manually polished. When the fixed mold is made, the fibers of the carbon fiber material are arranged horizontally. In this way, the axial deformation is small when the temperature drops from normal temperature to a low temperature environment. To a certain extent, the central cone column can save low-temperature calibration after normal temperature calibration, which is convenient to use. The central cone column is placed on the upper surface of the central cylinder and is in direct contact with the calibration mounting table 1 of the three-dimensional tester; the central cylinder is made of stainless steel material and processed by CNC technology. There is a tiny protrusion structure on the bottom, which is installed on the fine-tuning main body base, and the bottom and top need to be fine-ground; the fine-tuning main body base is the support seat of the central cylinder and the central cone column, and is made of stainless steel material. After the stainless steel material is formed by CNC processing, its surface is fine-ground by CNC, and the position can be fine-tuned through the fine-tuning hole 5. The fine-tuning main body base is fixed on the measuring table pillar 2. The outer cylinder 6 of the measuring platform is connected to the measuring platform base 3 through the measuring platform support 2. The measuring platform base 3 is fixed with fixed mounting holes for low-temperature heater elements, low-temperature temperature measuring elements and prefabricated force transfer rods. At the same time, the measuring platform base 3 is connected to the extremely low temperature end of the insulating support to be measured to transfer heat. The outer cylinder 6 of the measuring platform and the calibration platform fine-tuning body 4 are both installed on the top of the measuring platform support 2. The measuring platform support 2 has two forms, one is a composite material of G10 glass fiber and resin, and the other is non-expanding steel with a larger thermal conductivity and lower shrinkage at low temperatures. The choice is based on actual usage. The left view of the present invention is as follows: Figure 2 shown.

[0030] The measuring platform base 3 is at the bottom of the measuring platform pillar 2, and it controls the temperature and overall flatness of the measuring platform. After the low temperature end of the composite insulation support to be tested is connected to the measuring platform base 3, the three-dimensional tester calibration installation platform 1 is installed. Before the three-dimensional tester calibration installation platform 1 is installed, it is necessary to perform coarse adjustment of the horizontal and vertical displacements through the fine adjustment holes 5 to perform position calibration. After the three-dimensional tester calibration installation platform 1 is installed and before being cooled down, the three-dimensional displacement is finely adjusted through the calibration platform fine adjustment body 4, and the displacement accuracy is adjusted to a few microns. After the three-dimensional tester calibration installation platform 1 is connected to the three-dimensional measuring instrument, the three-dimensional tester calibration installation platform 1 needs to be fine-tuned. After the low temperature end of the composite insulation support and the measuring platform are cooled down, the measuring platform base 3 and the composite insulation support to be tested are heat exchanged, and the test platform is gradually cooled. The measuring platform pillar 2 is connected to the measuring platform base 3. According to the working temperature requirements of the three-dimensional tester calibration installation platform 1, the temperature of the measuring platform base 3 is controlled through the thermometer and heater on the measuring platform base 3, and then the temperature of the measuring platform pillar 2 is controlled. The force on the low temperature end of the tested insulation support is transmitted to the peripheral dynamometer through the prefabricated force transmission rod on the base 3 of the measuring platform, and is displayed on the remote computer through the dynamometer transmission line. The displacement of the low temperature end of the tested composite insulation support is measured by the three-dimensional tester installed on the three-dimensional tester calibration installation platform 1. The displacement change data signal of the insulation support under extremely low temperature is transmitted to the remote computer through optical fiber for real-time display and automatic data processing.

[0031] All parts of a precision displacement and force measuring platform for superconducting cavity insulation support at ultra-low temperature need to be calibrated in a constant temperature room. After all parts are calibrated and assembled, the overall calibration is performed. After the overall calibration is completed, it is connected to the ultra-low temperature end of the measured part, and then the overall fine-tuning is performed. Finally, the cryogenic temperature sensor, cryogenic heater, and force measuring guide rod are installed on the base of the measuring platform, and the overall signal and data are read and displayed by a remote computer.

[0032] The above contents are further detailed descriptions of the present application in combination with specific implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the inventive concept of the present application.

Claims

1. A precision measurement platform for displacement and force of an extremely low temperature insulation support for a superconducting cavity, characterized in that: It comprises a three-dimensional tester calibration installation platform (1), a measuring platform support (2), a measuring platform base (3), a calibration platform fine-tuning body (4) and a measuring platform outer cylinder (6); wherein: A three-dimensional tester calibration installation platform (1) is arranged on the top of the measuring platform outer cylinder (6); the bottom of the measuring platform outer cylinder (6) is connected to the measuring platform base (3) via a measuring platform support (2); A calibration platform fine-tuning body (4) is arranged inside the measuring platform outer cylinder (6); the bottom of the calibration platform fine-tuning body (4) is a fine-tuning body base, a central cylinder is arranged on the fine-tuning body base, and a central cone is arranged on the central cylinder; the top of the central cone is in direct contact with the three-dimensional tester calibration installation platform (1); the calibration platform fine-tuning body (4) is used for fine-tuning the three-dimensional displacement of the three-dimensional tester calibration installation platform (1); the central cylinder is made of non-expanding steel material, and a protruding structure is arranged at the bottom; the fine-tuning body base is made of non-expanding steel material; the measuring platform outer cylinder (6) is made of non-expanding steel material, and the three-dimensional tester calibration installation platform (1) is made of carbon fiber material; a fine-tuning hole (5) is arranged on the side of the measuring platform outer cylinder (6), and the position of the fine-tuning body base is adjusted through the fine-tuning hole (5), so as to realize the position calibration of the three-dimensional tester calibration installation platform (1) before the three-dimensional tester calibration installation platform (1) is installed and fixed on the top of the measuring platform outer cylinder (6); The measuring platform base (3) is provided with fixing holes for a low-temperature heater element, a low-temperature temperature measuring element and a prefabricated force transmission rod; the measuring platform base (3) is used to connect with the low-temperature end of the superconducting cavity insulation support member to be measured to transfer heat; the force at the low-temperature end of the superconducting cavity insulation support member to be measured is transmitted to the force gauge through the prefabricated force transmission rod, and the force data is transmitted to the data processing unit through the force gauge; the displacement of the low-temperature end of the superconducting cavity insulation support member to be measured is measured by a three-dimensional tester installed on the three-dimensional tester calibration installation platform (1) and transmitted to the data processing unit.

2. The displacement and force precision measuring platform of the superconducting cavity insulation support at ultra-low temperature as claimed in claim 1, characterized in that: The central cone column is made of carbon fiber material by fixed mold manufacturing and then polishing. When the fixed mold is manufactured, the fibers of the carbon fiber material are arranged horizontally.

3. The displacement and force precision measuring platform of the superconducting cavity insulation support at ultra-low temperature as claimed in claim 1, characterized in that: The measuring platform support (2) is made of a composite material of G10 glass fiber and resin.

4. The displacement and force precision measuring platform of the superconducting cavity insulation support at ultra-low temperature as claimed in claim 1, characterized in that: The measuring platform support (2) is made of inflatable steel.

5. A method for measuring displacement and force of an extremely low temperature insulating support for a superconducting cavity, using the displacement and force precision measuring platform for extremely low temperature insulating support for a superconducting cavity as claimed in claim 1, comprising the following steps: 1) After the low-temperature end of the superconducting cavity composite insulation support member to be tested is connected to the measuring platform base (3), the three-dimensional tester calibration installation platform (1) is pre-installed on the top of the measuring platform outer cylinder (6); wherein the bottom of the measuring platform outer cylinder (6) is connected to the measuring platform base (3) via the measuring platform support (2); a calibration platform fine-tuning body (4) is arranged inside the measuring platform outer cylinder (6); the bottom of the calibration platform fine-tuning body (4) is a fine-tuning body base, a central cylinder is arranged on the fine-tuning body base, and a central cone column is arranged on the central cylinder; the top of the central cone column is in direct contact with the three-dimensional tester calibration installation platform (1); 2) adjusting the position of the base of the fine-tuning main body through the fine-tuning hole (5) on the side of the outer cylinder (6) of the measuring platform, thereby realizing the position calibration of the three-dimensional tester calibration installation platform (1); then fine-tuning the three-dimensional displacement of the three-dimensional tester calibration installation platform (1) through the calibration platform fine-tuning main body (4), and then installing the three-dimensional tester calibration installation platform (1) on the top of the outer cylinder (6) of the measuring platform; 3) According to the working temperature requirement of the three-dimensional tester calibration installation platform (1), the temperature of the measuring platform base (3) is controlled by a thermometer and a heater on the measuring platform base (3), thereby controlling the temperature of the measuring platform support (2); 4) applying force to the low-temperature end of the superconducting cavity insulation support member to be measured, transmitting the force at the low-temperature end of the superconducting cavity insulation support member to the dynamometer via the prefabricated force transmission rod on the measuring platform base (3), and transmitting the force data to the data processing unit via the dynamometer; measuring the displacement of the low-temperature end of the superconducting cavity insulation support member via the three-dimensional tester installed on the three-dimensional tester calibration installation platform (1) and transmitting it to the data processing unit.

6. The method according to claim 5, characterized in that The central cone column is made of carbon fiber material by fixed mold manufacturing and then polishing. When the fixed mold is manufactured, the fibers of the carbon fiber material are arranged horizontally.

7. The method according to claim 5, characterized in that The measuring platform support (2) is made of inflatable steel.

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