A platform, system and method for testing the horizontal temperature of a radio frequency superconducting cavity

Abstract

The present invention provides a platform, a system and a method for use thereof for horizontal temperature testing of a radio frequency superconducting cavity, relating to the field of large-scale superfluid helium cryogenic refrigeration. The platform includes a horizontal test valve box, a plurality of return gas pipelines, a plurality of inlet gas pipelines, a negative pressure heat exchanger, a negative pressure protection and safety relief integrated device, a horizontal test valve box vacuum acquisition device, a cryostat vacuum acquisition device and a displacement pump group. By providing flanges on both the plurality of return gas pipelines and the plurality of inlet gas pipelines, mechanical connection interfaces are provided for cryostats of different types of radio frequency superconducting cavities. By providing cryogenic valves, pressure sensors and temperature sensors on both the plurality of return gas pipelines and the plurality of inlet gas pipelines, it is possible to provide the cryogenic cooling capacity required for testing according to the design requirements of the radio frequency superconducting cavity and corresponding design parameters, accurately obtain the working performance of the radio frequency superconducting cavity under the design conditions, and test its comprehensive design indicators, providing high-fidelity experimental data for the efficient and stable operation of the superconducting accelerator.

Description

Technical Field

[0001] The present invention relates to the technical field of large-scale superfluid helium cryogenic refrigeration technology, and particularly relates to a platform, a system and a usage method for horizontal temperature testing of a radio frequency superconducting cavity. Background Art

[0002] As the core cold mass of a superconducting accelerator, the radio frequency superconducting cavity is coupled with various types of cold masses such as couplers, superconducting solenoid coils and current leads, and undertakes the core task of particle acceleration. Due to the complex design and high integration of the radio frequency superconducting cavity, it must be horizontally tested when it is officially installed and put into operation. Usually, it refers to a test carried out under a fixed level (or condition) to evaluate the performance of the radio frequency superconducting cavity in a stable state. This test method can ensure that relevant problems are found, relevant data are obtained, and its performance indicators are verified for the radio frequency superconducting cavity under the designed working conditions.

[0003] At present, the designs of radio frequency superconducting cavities of different superconducting accelerators are different, and their process schemes are quite different from each other. Therefore, it is very urgent to develop a horizontal test system for different types of radio frequency superconducting cavities to realize experiments with multiple temperature regions and high stability, and to provide a reliable experimental system for the horizontal temperature testing experiments of radio frequency superconducting cavities of different superconducting accelerators. Summary of the Invention

[0004] The present invention provides a platform for horizontal temperature testing of a radio frequency superconducting cavity, which is used to solve the problems that the prior art cannot quickly and accurately obtain the working performance of different types of radio frequency superconducting cavities under the designed working conditions and cannot test their comprehensive design indicators.

[0005] The present invention provides a platform for horizontal temperature testing of a radio frequency superconducting cavity, including a horizontal test valve box, a plurality of return gas pipelines, a plurality of inlet gas pipelines, a negative pressure heat exchanger, a negative pressure protection and safety relief integrated device, a horizontal test valve box vacuum acquisition device, a cryostat vacuum acquisition device and a displacement pump group. Among them, the negative pressure heat exchanger, the plurality of return gas pipelines and the plurality of inlet gas pipelines are arranged in the horizontal test valve box. Low-temperature valves, pressure sensors and temperature sensors are arranged on the plurality of return gas pipelines and the plurality of inlet gas pipelines. The input end of the return gas pipeline is communicated with the output end of the corresponding cryostat, and the output end of the return gas pipeline is communicated with the distribution and transmission system. The input end of the inlet gas pipeline is communicated with the distribution and transmission system, and the output end of the inlet gas pipeline is communicated with the input end of the corresponding cryostat. The negative pressure heat exchanger is connected in series on one of the return gas pipelines and one of the inlet gas pipelines. The negative pressure protection and safety relief integrated device is communicated with the distribution and transmission system, the return gas pipeline, the displacement pump group and the cryostat. The horizontal test valve box vacuum acquisition device is communicated with the horizontal test valve box, and the cryostat vacuum acquisition device is communicated with the cryostat.

[0006] The multiple return gas pipelines include:

[0007] The first return gas pipeline, the input end of the first return gas pipeline is communicated with the output end of the corresponding thermostat, and the output end of the first return gas pipeline is communicated with the cold screen return gas pipeline of the distribution and transmission system;

[0008] The second return gas pipeline, the input end of the second return gas pipeline is communicated with the output end of the corresponding thermostat, and the output end of the second return gas pipeline is communicated with the coupler return gas pipeline of the distribution and transmission system;

[0009] The third return gas pipeline, the input end of the third return gas pipeline is communicated with the output end of the corresponding thermostat, and the output end of the third return gas pipeline is communicated with the 2K return gas pipeline of the distribution and transmission system;

[0010] The multiple intake air pipelines include:

[0011] The first intake air pipeline, the input end of the first intake air pipeline is communicated with the 4.5K gas supply pipeline of the distribution and transmission system, and the output end of the first intake air pipeline is communicated with the input end of the corresponding thermostat;

[0012] The second intake air pipeline, the input end of the second intake air pipeline is communicated with the cold screen gas supply pipeline of the distribution and transmission system, and the output end of the second intake air pipeline is communicated with the input end of the corresponding thermostat.

[0013] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, the first input port and the first output port of the negative pressure heat exchanger are connected in series to the third return gas pipeline, and the second input port and the second output port of the negative pressure heat exchanger are connected in series to the first intake air pipeline.

[0014] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, the first return gas pipeline is provided with a sixteenth cryogenic valve, a fifth pressure sensor, and a sixth temperature sensor, wherein the sixth temperature sensor is located between the sixteenth cryogenic valve and the fifth pressure sensor; the second return gas pipeline is provided with a thirteenth cryogenic valve, a sixth pressure sensor, and a seventh temperature sensor, wherein the seventh temperature sensor is located between the thirteenth cryogenic valve and the sixth pressure sensor; the third return gas pipeline is provided with a tenth cryogenic valve, an eleventh cryogenic valve, a first pressure sensor, a second pressure sensor, a first temperature sensor, a second temperature sensor, and an eighth temperature sensor, wherein the eleventh cryogenic valve is located between the eighth temperature sensor and the first output port of the negative pressure heat exchanger, the first temperature sensor and the first pressure sensor are located between the eleventh cryogenic valve and the first output port of the negative pressure heat exchanger, and the second pressure sensor and the second temperature sensor are located between the tenth cryogenic valve and the first input port of the negative pressure heat exchanger; the first intake pipeline is provided with a sixth cryogenic valve, a third pressure sensor, a fourth pressure sensor, a third temperature sensor, and a fourth temperature sensor, wherein the fourth pressure sensor and the fourth temperature sensor are located between the sixth cryogenic valve and the second output port of the negative pressure heat exchanger, and the third temperature sensor is located between the third pressure sensor and the second input port of the negative pressure heat exchanger; the second intake pipeline is provided with a ninth cryogenic valve, a seventh pressure sensor, and a fifth temperature sensor, wherein the seventh pressure sensor is located between the ninth cryogenic valve and the fifth temperature sensor.

[0015] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, the first return gas pipeline between the sixth temperature sensor and the sixteenth cryogenic valve is communicated with the cooling return gas pipeline of the distribution transmission system through a fifteenth cryogenic valve; the second return gas pipeline between the seventh temperature sensor and the thirteenth cryogenic valve is communicated with the cooling return gas pipeline of the distribution transmission system through a fourteenth cryogenic valve; the third return gas pipeline between the eleventh cryogenic valve and the first pressure sensor is communicated with the cooling return gas pipeline of the distribution transmission system through a twelfth cryogenic valve.

[0016] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, the multiple intake pipelines further include:

[0017] A third intake air pipeline, the input end of the third intake air pipeline is communicated with the first intake air pipeline between the third pressure sensor and the third temperature sensor, and the output end of the third intake air pipeline is communicated with the input end of the corresponding thermostat; the third intake air pipeline is provided with a seventh low-temperature valve, an eighth pressure sensor and a ninth temperature sensor, and the eighth pressure sensor is located between the seventh low-temperature valve and the ninth temperature sensor;

[0018] A fourth intake air pipeline, the input end of the fourth intake air pipeline is communicated with the first intake air pipeline between the third pressure sensor and the third temperature sensor, and the output end of the fourth intake air pipeline is communicated with the input end of the corresponding thermostat; the fourth intake air pipeline is provided with an eighth low-temperature valve.

[0019] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, a first temperature mixing device is arranged on the second intake air pipeline between the ninth low-temperature valve and the seventh pressure sensor, and the input end of the first temperature mixing device is communicated with the rewarming air supply pipeline of the distribution and transmission system through a sixth normal-temperature pneumatic valve;

[0020] A second temperature mixing device is arranged on the third intake air pipeline between the eighth pressure sensor and the seventh low-temperature valve, the second temperature mixing device is sequentially communicated with the rewarming air supply pipeline of the distribution and transmission system through a second one-way valve and a seventh normal-temperature pneumatic valve, and a tenth pressure sensor and a switch valve are arranged on the rewarming air supply pipeline of the distribution and transmission system.

[0021] According to a platform for horizontal temperature testing of a radio frequency superconducting cavity provided by the present invention, the first return air pipeline is communicated with a recovery and purification system through a first connecting pipeline, a third first-stage safety valve and a third bursting disc are arranged on the first connecting pipeline, and the first connecting pipeline between the third bursting disc and the first return air pipeline is communicated with a displacement pump group through a third normal-temperature pneumatic valve; the second return air pipeline is communicated with the recovery and purification system through a second connecting pipeline, and a second first-stage safety valve and a second bursting disc are arranged on the second connecting pipeline; the second connecting pipeline between the second bursting disc and the second return air pipeline is communicated with the displacement pump group through a second normal-temperature pneumatic valve;

[0022] The platform includes a first negative pressure protection and safety relief integrated device and a second negative pressure protection and safety relief integrated device. The air inlet of the first negative pressure protection and safety relief integrated device is communicated with the third return gas pipeline through a first one-way valve. The air supply port of the negative pressure protection and safety relief integrated device of the first negative pressure protection and safety relief integrated device is communicated with the low-pressure circuit branch of the refrigeration system of the distribution and transmission system. The replacement air outlet of the first negative pressure protection and safety relief integrated device is communicated with the replacement pump group through a fourth normal-temperature pneumatic valve. The recovered and purified air outlet of the first negative pressure protection and safety relief integrated device is communicated with the recovery and purification system. The pressure relief air outlet of the first negative pressure protection and safety relief integrated device is communicated with a first rupture disc through a first secondary safety valve.

[0023] The air inlet of the second negative pressure protection and safety relief integrated device is communicated with the thermostat. The air supply port of the negative pressure protection and safety relief integrated device of the second negative pressure protection and safety relief integrated device is communicated with the low-pressure circuit branch of the refrigeration system of the distribution and transmission system. The replacement air outlet of the second negative pressure protection and safety relief integrated device is communicated with the replacement pump group through a fifth normal-temperature pneumatic valve. The recovered and purified air outlet of the second negative pressure protection and safety relief integrated device is communicated with the recovery and purification system. The pressure relief air outlet of the second negative pressure protection and safety relief integrated device is communicated with a fourth rupture disc through a fourth secondary safety valve.

[0024] The present invention also provides a system for horizontal temperature testing of a radio frequency superconducting cavity. The system includes a helium storage system, a refrigeration system, a distribution and transmission system, a superfluid helium acquisition system, a recovery and purification system, a control integration system, and the platform for horizontal temperature testing of a radio frequency superconducting cavity according to any one of the above.

[0025] The present invention also provides a method for using the system for horizontal temperature testing of a radio frequency superconducting cavity, including:

[0026] Step S1, obtaining a vacuum for the horizontal test valve box by the horizontal test valve box vacuum obtaining device and obtaining a vacuum for the thermostat by the thermostat vacuum obtaining device, so as to maintain a vacuum state of the order of 1×10 -4 Pa for the horizontal test valve box and the thermostat.

[0027] Step S2: Open the sixth to sixteenth cryogenic valves, the first to fifth normal-temperature pneumatic valves, and the displacement pump set to evacuate the distribution and transmission system, multiple return gas pipelines and multiple intake gas pipelines in the horizontal test valve box; obtain the values of the first to ninth pressure sensors. When the maximum value among the values of the first to ninth pressure sensors is lower than 100 Pa, close the displacement pump set and the first to fifth normal-temperature pneumatic valves; then open the switch valve, the sixth normal-temperature pneumatic valve, and the seventh normal-temperature pneumatic valve, and slowly fill helium gas at 300 K into the pipeline. When the maximum value among the values of the first to ninth pressure sensors reaches 1.5 bar, close the switch valve, the sixth normal-temperature pneumatic valve, and the seventh normal-temperature pneumatic valve, and let it stand for the first predetermined time;

[0028] Step S3: Repeat Step S2 multiple times to ensure the replacement effect;

[0029] Step S4: Open the ninth cryogenic valve and the fifteenth cryogenic valve, and maintain the opening of the fifteenth cryogenic valve above 90%. Gradually increase the opening of the second cryogenic valve and the ninth cryogenic valve to cool the cold shield assembly of the horizontal test valve box and the cryostat. Obtain the value of the sixth temperature sensor. When the value of the sixth temperature sensor stabilizes at 75 K, open and slowly increase the opening of the sixteenth cryogenic valve, and slowly close the fifteenth cryogenic valve;

[0030] Step S5: Open the first cryogenic valve and the fourteenth cryogenic valve, then open the seventh cryogenic valve, and gradually increase the opening of the seventh cryogenic valve to prepare liquid helium at 4.5 K @ 1.3 bar; at the same time, open the sixth cryogenic valve and keep a small opening to cool the negative pressure heat exchanger;

[0031] Step S6: Control the opening of the seventh cryogenic valve so that the value of the 4.5 K liquid helium level gauge in the cryostat is 95%, and limit the minimum opening adjustment of the seventh cryogenic valve to 10%;

[0032] Step S7: Open the 2K gas heater of the superfluid helium acquisition system and preheat for the second predetermined time to fully activate the heater;

[0033] Step S8: Open the superfluid helium decompression and cooling pump set of the superfluid helium acquisition system, slowly close the seventh cryogenic valve, close the fourteenth cryogenic valve, and then slowly open the thirteenth cryogenic valve; gradually increase the opening of the sixth cryogenic valve to start throttling and decompression to obtain superfluid helium at 2K @ 0.03 bar;

[0034] Step S9: When the liquid helium at 4.5K@1.3bar in the thermostat turns into superfluid helium at 2K@0.03bar, adjust the opening degree of the sixth cryogenic valve to make the value of the 2K superfluid helium level gauge 95%, conduct the 2K test, and then adjust the minimum opening degree of the sixth cryogenic valve to 10%.

[0035] Step S10: After the test is completed, open the fourteenth cryogenic valve, close the thirteenth cryogenic valve and the superfluid helium acquisition system, and slowly close the first cryogenic valve and the second cryogenic valve to stop supplying cooling capacity to the horizontal test valve box and the thermostat.

[0036] Step S11: Turn on the solid-contact DC power heater in the thermostat and control the power of the solid-contact DC power heater within a predetermined range; when the value of the temperature sensor around the solid-contact DC power heater reaches 70K, turn off the solid-contact DC power heater.

[0037] Step S12: Open the switch valve, the fifth normal-temperature pneumatic valve, and the sixth normal-temperature pneumatic valve to input 300K normal temperature into the horizontal test valve box and the thermostat to accelerate the rewarming speed.

[0038] Step S13: When the value of the temperature sensor around the solid-contact DC power heater reaches normal temperature, turn off the vacuum pump groups of the horizontal test valve box vacuum acquisition device and the thermostat vacuum acquisition device.

[0039] The platform for horizontal temperature test of the radio frequency superconducting cavity provided by the present invention provides mechanical connection interfaces for the cryostats of different types of radio frequency superconducting cavities by setting flanges on multiple return gas pipelines and multiple intake gas pipelines. By setting cryogenic valves, pressure sensors, and temperature sensors on multiple return gas pipelines and multiple intake gas pipelines, it can provide the required cryogenic cooling capacity according to the design requirements of the radio frequency superconducting cavity and corresponding design parameters, accurately obtain the working performance of the radio frequency superconducting cavity under the design conditions, and test its comprehensive design indicators, providing high-fidelity experimental data for the efficient and stable operation of the superconducting accelerator. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic structural diagram of the system for horizontal temperature test of the radio frequency superconducting cavity provided by the present invention.

[0042] Figure 2Is Figure 1 The partial enlarged structure at position A in

[0043] Figure 3 Is Figure 1 The partial enlarged structure at position B in

[0044] Reference numerals:

[0045] 100, Horizontal test valve box; L1, First return air pipeline; L2, Second return air pipeline; L3, Third return air pipeline; L4, First intake air pipeline; L5, Second intake air pipeline; L6, Third intake air pipeline; L7, Fourth intake air pipeline; L8, Rewarming supply air pipeline; L9, Cooling return air pipeline; L10, Coupler return air pipeline; L11, 2K return air pipeline; L12, Cold screen return air pipeline; L13, Cold screen supply air pipeline; L14, 4.5K gas supply pipeline; L15, low-pressure branch of the refrigeration system; HX01, negative pressure heat exchanger; CV01, first cryogenic valve; CV02, second cryogenic valve; CV03, third cryogenic valve; CV04, fourth cryogenic valve; CV05, fifth cryogenic valve; CV06, sixth cryogenic valve; CV07, seventh cryogenic valve; CV08, eighth cryogenic valve; CV09, ninth cryogenic valve; CV10, tenth cryogenic valve; CV11, eleventh cryogenic valve; CV12, twelfth cryogenic valve; CV13, thirteenth cryogenic valve; CV14, fourteenth cryogenic valve; CV15, fifteenth cryogenic valve; CV16, sixteenth cryogenic valve; P1, first pressure sensor; P2, second pressure sensor; P3, third pressure sensor; P4, fourth pressure sensor; P5, fifth pressure sensor; P6, sixth pressure sensor; P7, seventh pressure sensor; P8, eighth pressure sensor; P9, ninth pressure sensor; P10, tenth pressure sensor; T1, first temperature sensor; T2, second temperature sensor; T3, third temperature sensor; T4, fourth temperature sensor; T5, fifth temperature sensor; T6, sixth temperature sensor; T7, seventh temperature sensor; T8, eighth temperature sensor; T9, ninth temperature sensor; T10, tenth temperature sensor; SVG01, first negative pressure protection and safety relief integrated device; SVG02, second negative pressure protection and safety relief integrated device; WV01, first normal temperature pneumatic valve; WV02, second normal temperature pneumatic valve; WV03, third normal temperature pneumatic valve; WV04, fourth normal temperature pneumatic valve; WV05, fifth normal temperature pneumatic valve; WV06, sixth normal temperature pneumatic valve; WV07, seventh normal temperature pneumatic valve; SV02, second primary safety valve; SV03, third primary safety valve; BP01, first rupture disc; BP02, second rupture disc; BP03, third rupture disc; BP04, fourth rupture disc; SV01-1, first primary safety valve; SV01-2, first secondary safety valve; SV04-1, fourth primary safety valve; SV04-2, fourth secondary safety valve; Mix1, first temperature mixing device; Mix2, second temperature mixing device; VN01, first check valve; VN02, second check valve; PV01, switch valve; VH01, vacuum cover; TS01, cold shield assembly of the horizontal test valve box; VS01, first vacuum silicon; Pump3, displacement pump group; BV01, first gate valve; BV02, second gate valve; Pump1, first displacement pump assembly; Pump2, second displacement pump assembly; VS02, second vacuum silicon; Ln, normal temperature pipeline; Lm, multi-channel transmission pipeline; 200, thermostat; 300, distribution transmission system; FL01, normal temperature flowmeter; HT01, 2K gas heater; Pump4, throttling and pressure reducing pump group. Detailed implementation mode

[0046] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without any creative effort fall within the scope of protection of the present invention.

[0047] Before introducing the platform for the horizontal temperature test of the radio frequency superconducting cavity, the cryostat 200 will be introduced first. The cryostat 200 is the core cold mass module integration system of the superconducting accelerator, including key components such as superconducting cavities, couplers, superconducting solenoid coils and current leads, and is responsible for the core task of particle acceleration. Due to its complex internal structure and high integration level, each component needs to operate normally under its respective designed working conditions. Therefore, before formal installation and operation, a horizontal test must be carried out, that is, to evaluate the stability performance of the system under specific conditions. This kind of test can discover potential problems, collect important data and verify the performance indicators. At present, the designs of cryostats and the cold mass process schemes of various superconducting accelerators are different. It is particularly urgent to develop a horizontal test system applicable to different cryostats 200 for experimental research with multiple temperature zones and high stability. This will provide a reliable experimental system for the horizontal test of cryostats of different types of superconducting accelerators and ensure their efficient and stable operation in practical applications.

[0048] As Figure 3 shown, the platform for the horizontal temperature test of the radio frequency superconducting cavity includes a horizontal test valve box 100, multiple return gas pipelines, multiple inlet gas pipelines, a negative pressure heat exchanger HX01, a negative pressure protection and safety relief integrated device, a horizontal test valve box vacuum acquisition device, a cryostat vacuum acquisition device and a replacement pump group Pump3. Among them, the negative pressure heat exchanger HX01, multiple return gas pipelines and multiple inlet gas pipelines are arranged in the horizontal test valve box 100. Low-temperature valves, pressure sensors and temperature sensors are arranged on both the multiple return gas pipelines and the multiple inlet gas pipelines. The input end of the return gas pipeline is communicated with the output end of the corresponding cryostat 200, and the output end of the return gas pipeline is communicated with the distribution and transmission system 300; the input end of the inlet gas pipeline is communicated with the distribution and transmission system 300, and the output end of the inlet gas pipeline is communicated with the input end of the corresponding cryostat 200. The negative pressure heat exchanger HX01 is connected in series to one of the return gas pipelines and one of the inlet gas pipelines. The negative pressure protection and safety relief integrated device is communicated with the distribution and transmission system 300, the return gas pipeline, the replacement pump group Pump3 and the cryostat 200; the horizontal test valve box vacuum acquisition device is communicated with the horizontal test valve box 100, and the cryostat vacuum acquisition device is communicated with the cryostat 200.

[0049] The platform for horizontal temperature testing of the radio frequency superconducting cavity provided by the present invention can provide the required cryogenic cooling capacity according to the design requirements of the radio frequency superconducting cavity and corresponding design parameters by setting cryogenic valves, pressure sensors and temperature sensors on multiple return gas pipelines and multiple inlet gas pipelines. It can accurately obtain the working performance of the radio frequency superconducting cavity under the design conditions, test its comprehensive design indicators, and provide high-fidelity experimental data for the efficient and stable operation of the superconducting accelerator.

[0050] In an embodiment of the present invention, the horizontal test valve box 100 includes a vacuum cover VH01 and a horizontal test valve box cold screen assembly TS01. The horizontal test valve box cold screen assembly TS01 is arranged inside the vacuum cover VH01. A tenth temperature sensor T10 is arranged inside the horizontal test valve box cold screen assembly TS01. The tenth temperature sensor T10 is used to judge the cooling state of the cold screen. There are multiple tenth temperature sensors T10. Specifically, there are six tenth temperature sensors T10, with a part used for measurement and the other part as a backup.

[0051] Furthermore, a first vacuum silicon VS01 is provided at the top of the vacuum cover VH01. The first vacuum silicon VS01 is electrically connected to the vacuum monitor and is used to detect the vacuum state of the internal interlayer of the horizontal test valve box.

[0052] In an embodiment of the present invention, the horizontal test valve box vacuum acquisition device includes a first gate valve BV01 located at the top of the vacuum cover VH01 and a first replacement pump assembly Pump1 located on the ground foundation. The first gate valve BV01 is connected to the first replacement pump assembly Pump1 through a flange. The first replacement pump assembly Pump1 includes a primary mechanical pump and a secondary molecular pump.

[0053] In an embodiment of the present invention, a second vacuum silicon VS02 is arranged on the top cover of the thermostat 200. The second vacuum silicon VS02 is electrically connected to the vacuum monitor and is used to detect the vacuum state of the interlayer of the thermostat. The signals of the high-precision temperature sensor, high-precision positive pressure sensor, high-precision negative pressure sensor, 4.5K liquid helium level gauge, 2K superfluid helium level gauge, solid contact heater and built-in cryogenic valve controller inside the thermostat 200 are all connected to the control integration system for signal acquisition and controller control.

[0054] In an embodiment of the present invention, the thermostat vacuum acquisition device includes a second gate valve BV02 and a second replacement pump assembly Pump2. The second gate valve BV02 is arranged on the top cover of the thermostat 200. The second gate valve BV02 is connected to the second replacement pump assembly Pump2 through a flange. The second replacement pump assembly Pump2 includes a primary mechanical pump and a secondary molecular pump.

[0055] In an embodiment of the present invention, the multiple return gas pipelines include a first return gas pipeline L1, a second return gas pipeline L2, and a third return gas pipeline L3, and the multiple intake gas pipelines include a first intake gas pipeline L4 and a second intake gas pipeline L5. The input end of the first return gas pipeline L1 is communicated with the output end of the corresponding thermostat 200, and the output end of the first return gas pipeline L1 is communicated with the cold shield return gas pipeline L12 of the distribution and transmission system 300. The input end of the second return gas pipeline L2 is communicated with the output end of the corresponding thermostat 200, and the output end of the second return gas pipeline L2 is communicated with the coupler return gas pipeline L10 of the distribution and transmission system 300. The input end of the third return gas pipeline L3 is communicated with the output end of the corresponding thermostat 200, and the output end of the third return gas pipeline L3 is communicated with the 2K return gas pipeline L11 of the distribution and transmission system 300. The input end of the first intake gas pipeline L4 is communicated with the 4.5K gas supply pipeline L14 of the distribution and transmission system 300, and the output end of the first intake gas pipeline L4 is communicated with the input end of the corresponding thermostat 200. The input end of the second intake gas pipeline L5 is communicated with the cold shield gas supply pipeline L13 of the distribution and transmission system 300, and the output end of the second intake gas pipeline L5 is communicated with the input end of the corresponding thermostat 200.

[0056] In an embodiment of the present invention, the negative pressure heat exchanger HX01 is located inside the horizontal test valve box 100, and the first input port and the first output port of the negative pressure heat exchanger HX01 are connected in series to the third return gas pipeline L3. Specifically, the third return gas pipeline L3 is a helium gas pipeline. The first input port of the negative pressure heat exchanger HX01 is connected to the output port of the thermostat 200 through the third return gas pipeline L3, and the first output port of the negative pressure heat exchanger HX01 is communicated with the 2K return gas pipeline L11 of the distribution and transmission system 300 through the third return gas pipeline L3.

[0057] The second input port and the second output port of the negative pressure heat exchanger HX01 are connected in series to the first intake gas pipeline L4. Specifically, the second output port of the negative pressure heat exchanger HX01 is communicated with the input end of the thermostat 200 through the first intake gas pipeline L4, and the second input port of the negative pressure heat exchanger HX01 is communicated with the supercritical helium gas pipeline at 4.5K@3bar from the refrigerator system, that is, communicated with the 4.5K gas supply pipeline L14 of the distribution and transmission system 300, through the first intake gas pipeline L4.

[0058] Before the supercritical helium gas at 4.5K@3bar enters the thermostat 200 through the negative pressure heat exchanger HX01, it passes through the sixth cryogenic valve CV06. The sixth cryogenic valve CV06 and the seventh cryogenic valve CV07 are pneumatic Joule-Thomson throttle valves (J-T valves).

[0059] Furthermore, in the 2K mode, the negative pressure heat exchanger HX01 cooperates with the sixth cryogenic valve CV06 and the superfluid helium decompression and cooling pump set to complete throttling and decompression.

[0060] In an embodiment of the present invention, a sixteenth cryogenic valve CV16, a fifth pressure sensor P5, and a sixth temperature sensor T6 are provided on the first return gas pipeline L1, wherein the sixth temperature sensor T6 is located between the sixteenth cryogenic valve CV16 and the fifth pressure sensor P5; a thirteenth cryogenic valve CV13, a sixth pressure sensor P6, and a seventh temperature sensor T7 are provided on the second return gas pipeline L2, wherein the seventh temperature sensor T7 is located between the thirteenth cryogenic valve CV13 and the sixth pressure sensor P6; a tenth cryogenic valve CV10, an eleventh cryogenic valve CV11, a first pressure sensor P1, a second pressure sensor P2, a first temperature sensor T1, a second temperature sensor T2, and an eighth temperature sensor T8 are provided on the third return gas pipeline L3, wherein the eleventh cryogenic valve CV11 is located between the eighth temperature sensor T8 and the first output port of the negative pressure heat exchanger HX01, the first temperature sensor T1 and the first pressure sensor P1 are located between the eleventh cryogenic valve CV11 and the first output port of the negative pressure heat exchanger HX01, and the second pressure sensor P2 and the second temperature sensor T2 are located between the tenth cryogenic valve CV10 and the first input port of the negative pressure heat exchanger HX01; a sixth cryogenic valve CV06, a third pressure sensor P3, a fourth pressure sensor P4, a third temperature sensor T3, and a fourth temperature sensor T4 are provided on the first intake pipeline L4, wherein the fourth pressure sensor P4 and the fourth temperature sensor T4 are located between the sixth cryogenic valve CV06 and the second output port of the negative pressure heat exchanger HX01, and the third temperature sensor T3 is located between the third pressure sensor P3 and the second input port of the negative pressure heat exchanger HX01; a ninth cryogenic valve CV09, a seventh pressure sensor P7, and a fifth temperature sensor T5 are provided on the second intake pipeline L5, wherein the seventh pressure sensor P7 is located between the ninth cryogenic valve CV09 and the fifth temperature sensor T5.

[0061] After the supercritical helium gas from the refrigerator system at 4.5K@3bar enters the horizontal test valve box 100, it is divided into two branches and enters the thermostat 200, that is, it enters the thermostat 200 through the first intake pipeline L4 and the third intake pipeline L6. Among them, after passing through the seventh cryogenic valve CV07 in the third intake pipeline L6, it flows into the thermostat 200. After flowing through the negative pressure heat exchanger HX01 in the first intake pipeline L4, it then passes through the seventh cryogenic valve CV07 and flows into the thermostat 200.

[0062] Furthermore, the first pressure sensor P1 is a positive pressure high-precision pressure sensor, the second pressure sensor P2 is a negative pressure high-precision pressure sensor, and both the third pressure sensor P3 and the fourth pressure sensor P4 are positive pressure high-precision pressure sensors.

[0063] Further, the horizontal test valve box 100 sends the helium gas from the refrigerator system 50K into the horizontal test valve box cold shield assembly TS01 via the ninth cryogenic valve CV09, and then flows into the thermostat cold shield assembly through the second intake pipeline L5. After the return air flows through the fifteenth cryogenic valve CV15 and the sixteenth cryogenic valve CV16, it returns to the refrigerator system.

[0064] In an embodiment of the present invention, the first return air pipeline L1 between the sixth temperature sensor T6 and the sixteenth cryogenic valve CV16 is connected to the cooling return air pipeline L9 of the distribution and transmission system 300 through the fifteenth cryogenic valve CV15; the second return air pipeline L2 between the seventh temperature sensor T7 and the thirteenth cryogenic valve CV13 is connected to the cooling return air pipeline L9 of the distribution and transmission system 300 through the fourteenth cryogenic valve CV14; the third return air pipeline L3 between the eleventh cryogenic valve CV11 and the first pressure sensor P1 is connected to the cooling return air pipeline L9 of the distribution and transmission system 300 through the twelfth cryogenic valve CV12.

[0065] In this embodiment, the eighth cryogenic valve CV08 to the sixteenth cryogenic valve CV16 are all pneumatic control valves. The eleventh cryogenic valve CV11 and the twelfth cryogenic valve CV12 are in a parallel connection relationship, the thirteenth cryogenic valve CV13 and the fourteenth cryogenic valve CV14 are in a parallel connection relationship, and the fifteenth cryogenic valve CV15 and the sixteenth cryogenic valve CV16 are in a parallel connection relationship.

[0066] The horizontal test valve box 100 sends the helium gas from the refrigerator system 50K into the horizontal test valve box cold shield assembly TS01 and the thermostat cold shield assembly via the ninth cryogenic valve CV09. After the return air flows through the fifteenth cryogenic valve CV15 or the sixteenth cryogenic valve CV16, it returns to the refrigerator system.

[0067] In an embodiment of the present invention, the multiple intake pipelines further include a third intake pipeline L6 and a fourth intake pipeline L7. The input end of the third intake pipeline L6 is connected to the first intake pipeline L4 between the third pressure sensor P3 and the third temperature sensor T3, and the output end of the third intake pipeline L6 is connected to the input end of the corresponding thermostat 200; the third intake pipeline L6 is provided with a seventh cryogenic valve CV07, an eighth pressure sensor P8, and a ninth temperature sensor T9, and the eighth pressure sensor P8 is located between the seventh cryogenic valve CV07 and the ninth temperature sensor T9; the input end of the fourth intake pipeline L7 is connected to the first intake pipeline L4 between the third pressure sensor P3 and the third temperature sensor T3, and the output end of the fourth intake pipeline L7 is connected to the input end of the corresponding thermostat 200; the fourth intake pipeline L7 is provided with an eighth cryogenic valve CV08.

[0068] In an embodiment of the present invention, a first temperature mixing device Mix1 is provided in a second intake pipeline L5 between a ninth cryogenic valve CV09 and a seventh pressure sensor P7. The input end of the first temperature mixing device Mix1 is connected to a rewarming air supply pipeline L8 of a distribution and transmission system 300 through a sixth normal temperature pneumatic valve WV06; a second temperature mixing device Mix2 is provided in a third intake pipeline L6 between an eighth pressure sensor P8 and a seventh cryogenic valve CV07. The second temperature mixing device Mix2 is sequentially connected to the rewarming air supply pipeline L8 of the distribution and transmission system 300 through a second one-way valve VN02 and a seventh normal temperature pneumatic valve WV07. A tenth pressure sensor P10 and a switching valve PV01 are provided on the rewarming air supply pipeline L8 of the distribution and transmission system 300.

[0069] The high-pressure gas from the refrigeration system enters the first temperature mixing device Mix1 through the sixth normal temperature pneumatic valve WV06, mixes with the helium gas from the ninth cryogenic valve CV09, and then enters the cold shield assembly TS01 of the horizontal test valve box. The high-pressure gas from the refrigeration system enters the second temperature mixing device Mix2 after passing through the seventh normal temperature pneumatic valve WV07 and the second one-way valve VN02, mixes with the helium gas from the seventh cryogenic valve CV07, and then enters the thermostat 200. Among them, the second one-way valve VN02 can effectively eliminate the influence of the thermoacoustic oscillation phenomenon generated in the temperature range below 4.5K on the measurement of the eighth pressure sensor P8.

[0070] In an embodiment of the present invention, a first return pipeline L1 is connected to a recovery and purification system through a first connecting pipeline. A third primary safety valve SV03 and a third rupture disc BP03 are provided on the first connecting pipeline. The first connecting pipeline between the third rupture disc BP03 and the first return pipeline L1 is connected to a displacement pump set Pump3 through a third normal temperature pneumatic valve WV03; a second return pipeline L2 is connected to the recovery and purification system through a second connecting pipeline. A second primary safety valve SV02 and a second rupture disc BP02 are provided on the second connecting pipeline; the second connecting pipeline between the second rupture disc BP02 and the second return pipeline L2 is connected to the displacement pump set Pump3 through a second normal temperature pneumatic valve WV02.

[0071] The platform includes a first negative pressure protection and safety relief integrated device SVG01 and a second negative pressure protection and safety relief integrated device SVG02. The air inlet of the first negative pressure protection and safety relief integrated device SVG01 is connected to the third return air pipeline L3 through a first one-way valve VN01. The negative pressure protection and safety relief integrated device air supply port of the first negative pressure protection and safety relief integrated device SVG01 is connected to the low-pressure branch L15 of the refrigeration machine system of the distribution and transmission system 300. The replacement air outlet of the first negative pressure protection and safety relief integrated device SVG01 is connected to the replacement pump group Pump3 through a fourth normal-temperature pneumatic valve WV04; the recovered and purified air outlet of the first negative pressure protection and safety relief integrated device SVG01 is connected to the recovery and purification system and is connected to the replacement pump group Pump3 through a first normal-temperature pneumatic valve WV01. The air inlet of the second negative pressure protection and safety relief integrated device SVG02 is connected to the thermostat 200. The negative pressure protection and safety relief integrated device air supply port of the second negative pressure protection and safety relief integrated device SVG02 is connected to the low-pressure branch L15 of the refrigeration machine system of the distribution and transmission system 300. The replacement air outlet of the second negative pressure protection and safety relief integrated device SVG02 is connected to the replacement pump group Pump3 through a fifth normal-temperature pneumatic valve WV05; the recovered and purified air outlet of the second negative pressure protection and safety relief integrated device SVG02 is connected to the recovery and purification system. The replacement pump group Pump3 is used to evacuate the gas environment inside the replacement pipeline. The replacement pump group Pump3 includes a first-stage mechanical pump and a second-stage molecular pump.

[0072] By setting a first one-way valve VN01 between the air inlet of the first negative pressure protection and safety relief integrated device SVG01 and the third return air pipeline L3, the first one-way valve VN01 can prevent thermoacoustic oscillations below the 4.5K temperature range and avoid the safety valve and bursting disc from working under incorrect pressures.

[0073] The first-stage safety valve SV01-1 is encapsulated inside the first negative pressure protection and safety relief integrated device SVG01. The air outlet of the first negative pressure protection and safety relief integrated device SVG01 is connected to the first bursting disc BP01 through a second-stage safety valve SV01-2. The fourth-stage safety valve SV04-1 is encapsulated inside the second negative pressure protection and safety relief integrated device SVG02. The air outlet of the second negative pressure protection and safety relief integrated device SVG02 is connected to the fourth bursting disc BP04 through a fourth-stage safety valve SV04-2.

[0074] Such as Figure 1 and Figure 2As shown in the figure, the present invention also provides a system for horizontal temperature measurement of a radio frequency superconducting cavity. The system includes a helium storage system, a refrigerator system, a distribution and transmission system 300, a superfluid helium acquisition system, a recovery and purification system, a control integration system, and the platform for horizontal temperature measurement of a radio frequency superconducting cavity described in any one of the above embodiments. Among them, the helium storage system is connected to the refrigerator system and the recovery and purification system. The refrigerator system is connected to the superfluid helium acquisition system and the distribution and transmission system 300. The recovery and purification system is connected to the platform for cryogenic testing and the thermostat 200.

[0075] The helium storage system is a gas storage tank. The helium storage system includes 7 high-purity helium storage tanks, which internally have high-pressure high-purity helium gas with a purity greater than 99.999% maintained at about 8 bar, a low-purity helium storage tank, which stores helium gas from the recovery and purification system, and a liquid nitrogen storage tank, which contains 50 Nm 3 of liquid nitrogen, which is the necessary helium gas and liquid ammonia to maintain the operation of the entire superfluid helium cryogenic system; the helium storage system can perform high and low pressure stamping or pressure relief on the refrigerator system to maintain the stable operation of the refrigerator system.

[0076] The refrigerator system is a large cryogenic device developed based on the Claude cycle pre-cooled by liquid nitrogen, including a compressor, an oil removal and drying component, and a refrigerator cold box. The helium compressor can compress low-pressure helium gas at 1.05 bar to 13 bar. The oil removal and drying component removes oil and a small amount of water vapor, NO x , H2, and O2 from the high-pressure helium gas from the helium compressor and then sends it into the refrigerator cold box. The refrigerator cold box includes heat exchangers and turbines at all levels, which expand and cool the high-pressure helium gas at 300 K @ 13 bar to supercritical helium at 4.5 K @ 3.5 bar.

[0077] The superfluid helium acquisition system includes a normal temperature flow meter FL01, a 2K gas heater HT01, and a throttling and decompression pump group Pump4 connected in series in sequence, which is used to achieve pressure reduction and temperature reduction to obtain superfluid helium at 2K @ 0.03 bar. The throttling and decompression pump group Pump4 includes 4 sub-pump groups. Each sub-pump group includes a first-stage mechanical pump and a second-stage Roots pump, which provides a pressure reduction capacity of 2 g / s under rated conditions. The maximum power of the 2K gas heater is 18 kW, which heats the gas to normal temperature and then sends it into the throttling and decompression pump group Pump4. The normal temperature flow meter FL01 is used to adjust the start and stop control of the sub-pump groups in the throttling and decompression pump group Pump4. The superfluid helium acquisition system is connected to the liquid helium return pipeline in the horizontal test valve box. After the superfluid helium acquisition system is started, the liquid helium at 4.5K @ 1.3 bar in the dewar is prepared into superfluid helium at 2K @ 0.03 bar, and the pumped-back 2K gas is heated to normal temperature and then sent back to the refrigerator system;

[0078] The recovery and purification system can recover and purify helium in the event of an emergency water or power outage, or when a safety valve trips or a bursting disc explodes, and deliver it to the helium storage system after reaching 99.999%.

[0079] The distribution and transmission system 300 includes a low-pressure branch line L15 of the refrigeration system, a normal temperature pipeline Ln and a multi-channel transmission pipeline Lm, wherein the normal temperature pipeline Ln includes a rewarming air supply pipeline L8 and a cooling return air pipeline L9, and the multi-channel transmission pipeline Lm includes a coupler return air pipeline L10, a 2K return air pipeline L11, a cold screen return air pipeline L12, a cold screen supply air pipeline L13 and a 4.5K supply air pipeline L14. The low-pressure branch L15 of the refrigerator system is provided with a fifth cryogenic valve CV05, the switch valve PV01 is located at one end of the rewarming air supply pipeline L8 close to the refrigerator system, the fourth cryogenic valve CV04 is provided at one end of the coupler return air pipeline L10 close to the refrigerator system, the third cryogenic valve CV03 is provided at one end of the cold screen return air pipeline L12 close to the refrigerator system, the second cryogenic valve CV02 is provided at one end of the cold screen supply air pipeline L13 close to the refrigerator system, and the first cryogenic valve CV01 is provided at one end of the 4.5K supply air pipeline L14 close to the refrigerator system.

[0080] The refrigerator system delivers 4.5K@3bar supercritical helium into the horizontal test valve box 100 through the 4.5K gas supply pipeline L14, delivers 50K@7bar low-temperature helium into the horizontal test valve box 100 through the cold shield gas supply pipeline L13, and the cold shield return gas of 75K@6bar is sent back to the refrigerator system through the cold shield return gas pipeline L12. In the 2K mode, the 2K gas from the thermostat 200 is sent into the superfluid helium acquisition system through the 2K return gas pipeline L11, and the cold shield return gas and the return gas from the thermostat 200 are sent back to the refrigerator system through the coupler return gas pipeline L10; the refrigerator system delivers 300K@4bar high-pressure helium into the first temperature mixer Mix1 through the sixth normal temperature pneumatic valve WV06 through the rewarming gas supply pipeline L8, and delivers it into the second temperature mixer Mix2 through the seventh normal temperature pneumatic valve WV07 and the second check valve VN02.

[0081] The refrigerator system delivers 300K@1.05bar normal temperature helium into the first negative pressure protection and safety relief integrated device SVG01 and the second negative pressure protection and safety relief integrated device SVG02 through the refrigerator system low-pressure branch L15 of the distribution transmission system 300, maintains a slightly positive pressure environment in the negative pressure protection and safety relief integrated device, and prevents air from invading the refrigerator system through the safety valve.

[0082] The control integration system is electrically connected to all temperature sensors, positive pressure sensors, negative pressure sensors, 4.5K liquid helium level gauges, 2K superfluid helium level gauges, fluid-contact DC power heaters, solid-contact DC power heaters, cryogenic valves, flow meters, normal-temperature valves, gate valves, horizontal test valve box vacuum acquisition equipment, thermostat vacuum acquisition equipment, displacement pump sets, sensors and controllers for the vertical test of superconducting cavities. The controller integration system includes the automatic control of the controller and the data acquisition unit of various sensors.

[0083] The present invention also provides a method for using a system for horizontal temperature test of a radio frequency superconducting cavity, including:

[0084] Step S1, evacuating the horizontal test valve box through the horizontal test valve box vacuum acquisition equipment and evacuating the thermostat through the thermostat vacuum acquisition equipment, so that the horizontal test valve box and the thermostat maintain a vacuum state of the order of 1×10 -4 Pa;

[0085] Step S1 specifically includes: closing all valves except the first gate valve BV01 and the second gate valve BV02, activating the first displacement pump assembly Pump1 of the horizontal test valve box vacuum acquisition equipment and the second displacement pump assembly Pump2 of the thermostat vacuum acquisition equipment, and simultaneously observing the feedback data of the first vacuum silicon VS01 at the top of the vacuum chamber of the horizontal test valve box and the second vacuum silicon VS02 on the top cover of the thermostat 200, so that the interlayer vacuum of the horizontal test valve box 100 and the thermostat 200 maintains a vacuum state of the order of 1×10 -4 Pa during the experimental period.

[0086] Step S2, opening the sixth cryogenic valve CV06 to the sixteenth cryogenic valve CV16, the first normal-temperature pneumatic valve WV01 to the fifth normal-temperature pneumatic valve WV05, and the displacement pump set Pump3 to evacuate the distribution and transmission system 300, multiple return gas pipelines and multiple intake gas pipelines in the horizontal test valve box 100; obtaining the values of the first pressure sensor P1 to the ninth pressure sensor P9, and when the maximum value among the values of the first pressure sensor P1 to the ninth pressure sensor P9 is lower than 100 Pa, closing the displacement pump set Pump3 and the first normal-temperature pneumatic valve WV01 to the fifth normal-temperature pneumatic valve WV05; then opening the switch valve PV01, the sixth normal-temperature pneumatic valve WV06, and the seventh normal-temperature pneumatic valve WV07, and slowly filling helium gas at 300K into the pipeline. When the maximum value among the values of the first pressure sensor P1 to the ninth pressure sensor P9 reaches 1.5 bar, closing the switch valve PV01, the sixth normal-temperature pneumatic valve WV06, and the seventh normal-temperature pneumatic valve WV07, and standing for the first predetermined time;

[0087] It should be noted here that in this embodiment, the first predetermined time is 15 minutes. After completing step S2, helium gas is fully diffused into each pipeline to complete one gas replacement process inside the pipeline.

[0088] Step S3, repeat step S2 multiple times to ensure the replacement effect;

[0089] It should be noted here that in this embodiment, step S2 is repeated five times. Of course, the number of repetitions is not limited to five times and can also be four times, six times or more.

[0090] Step S4, open the ninth cryogenic valve CV09 and the fifteenth cryogenic valve CV15, and maintain the opening of the fifteenth cryogenic valve CV15 above 90%. Gradually increase the opening of the second cryogenic valve CV02 and the ninth cryogenic valve CV09 to cool the cold shield assembly of the horizontal test valve box 100 and the cryostat 200, and obtain the value of the sixth temperature sensor T6. When the value of the sixth temperature sensor T6 stabilizes at 75K, open and slowly and gradually increase the opening of the sixteenth cryogenic valve CV16, and slowly close the fifteenth cryogenic valve CV15 for high-cooling recovery;

[0091] Step S5, open the first cryogenic valve CV01 and the fourteenth cryogenic valve CV14, then open the seventh cryogenic valve CV07, and gradually increase the opening of the seventh cryogenic valve CV07 to prepare liquid helium at 4.5K@1.3bar; at the same time, open the sixth cryogenic valve CV06 and keep a small opening to cool the negative pressure heat exchanger HX01;

[0092] Step S6, control the opening of the seventh cryogenic valve CV07 so that the value of the 4.5K liquid helium level gauge in the cryostat 200 is 95%, and limit the minimum opening adjustment of the seventh cryogenic valve CV07 to 10%;

[0093] Adjusting the minimum opening of the seventh cryogenic valve CV07 to 10% can prevent overpressure in the pipeline, causing the bursting disc to burst and the safety valve to operate.

[0094] Step S7, open the 2K gas heater of the superfluid helium acquisition system and preheat for the second predetermined time to fully activate the heater;

[0095] It should be noted here that the second predetermined time is 20 minutes. Of course, the second predetermined time is not limited to this and is specifically determined according to actual needs.

[0096] Step S8: Turn on the superfluid helium decompression and cooling pump set of the superfluid helium acquisition system, slowly close the seventh cryogenic valve CV07, close the fourteenth cryogenic valve CV14, and then slowly open the thirteenth cryogenic valve CV13; gradually increase the opening of the sixth cryogenic valve CV06 to start throttling and decompression to obtain superfluid helium at 2K@0.03bar.

[0097] Step S9: When the liquid helium at 4.5K@1.3bar in the cryostat 200 is transformed into superfluid helium at 2K@0.03bar, adjust the opening of the sixth cryogenic valve CV06 to make the value of the 2K superfluid helium level gauge 95% for 2K testing, and then adjust the minimum opening of the sixth cryogenic valve CV06 to 10%.

[0098] Adjusting the minimum opening of the sixth cryogenic valve CV06 to 10% can prevent overpressure in this pipeline, causing the rupture disk to burst and the safety valve to operate. All required data are obtained by the control integration system.

[0099] Step S10: After the test is completed, open the fourteenth cryogenic valve CV14, close the thirteenth cryogenic valve CV13 and the superfluid helium acquisition system, and slowly close the first cryogenic valve CV01 and the second cryogenic valve CV02 to stop supplying cooling to the horizontal test valve box 100 and the cryostat 200.

[0100] Step S11: Turn on the solid-contact DC power heater in the cryostat 200 and control the power of the solid-contact DC power heater within a predetermined range; when the value of the temperature sensor around the solid-contact DC power heater reaches 70K, turn off the solid-contact DC power heater.

[0101] It should be noted here that in this embodiment, the predetermined range is 80% of the full power. Of course, the second predetermined range is not limited to this and is specifically determined according to actual needs.

[0102] Step S12: Open the switch valve PV01, the fifth normal-temperature pneumatic valve WV05, and the sixth normal-temperature pneumatic valve WV06 to input 300K normal temperature into the horizontal test valve box 100 and the cryostat 200 to accelerate the rewarming speed.

[0103] Step S13: When the value of the temperature sensor around the solid-contact DC power heater reaches normal temperature, turn off the vacuum pump sets of the horizontal test valve box vacuum acquisition device and the cryostat vacuum acquisition device.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A platform for horizontal temperature testing of a radio frequency superconducting cavity, characterized in that, It includes a horizontal test valve box, multiple return gas pipelines, multiple intake gas pipelines, a negative pressure heat exchanger, a negative pressure protection and safety relief integrated device, a horizontal test valve box vacuum acquisition device, a thermostat vacuum acquisition device, and a replacement pump group. Among them, the negative pressure heat exchanger, multiple return gas pipelines, and multiple intake gas pipelines are arranged in the horizontal test valve box. Low-temperature valves, pressure sensors, and temperature sensors are arranged on both the multiple return gas pipelines and the multiple intake gas pipelines. The input end of the return gas pipeline is connected to the output end of the corresponding thermostat, and the output end of the return gas pipeline is connected to the distribution and transmission system; the input end of the intake gas pipeline is connected to the distribution and transmission system, and the output end of the intake gas pipeline is connected to the input end of the corresponding thermostat. The negative pressure heat exchanger is connected in series to one of the return gas pipelines and one of the intake gas pipelines. The negative pressure protection and safety relief integrated device is connected to the distribution and transmission system, the return gas pipeline, the replacement pump group, and the thermostat; the horizontal test valve box vacuum acquisition device is connected to the horizontal test valve box, and the thermostat vacuum acquisition device is connected to the thermostat; The multiple return gas pipelines include: The first return gas pipeline, the input end of the first return gas pipeline is connected to the output end of the corresponding thermostat, and the output end of the first return gas pipeline is connected to the cold shield return gas pipeline of the distribution and transmission system; The second return gas pipeline, the input end of the second return gas pipeline is connected to the output end of the corresponding thermostat, and the output end of the second return gas pipeline is connected to the coupler return gas pipeline of the distribution and transmission system; The third return gas pipeline, the input end of the third return gas pipeline is connected to the output end of the corresponding thermostat, and the output end of the third return gas pipeline is connected to the 2K return gas pipeline of the distribution and transmission system; The multiple intake gas pipelines include: The first intake gas pipeline, the input end of the first intake gas pipeline is connected to the 4.5K gas supply pipeline of the distribution and transmission system, and the output end of the first intake gas pipeline is connected to the input end of the corresponding thermostat; The second intake gas pipeline, the input end of the second intake gas pipeline is connected to the cold shield gas supply pipeline of the distribution and transmission system, and the output end of the second intake gas pipeline is connected to the input end of the corresponding thermostat.

2. The platform for horizontal temperature measurement of a radio frequency superconducting cavity according to claim 1, characterized in that, The first input port and the first output port of the negative pressure heat exchanger are connected in series to the third return gas pipeline, and the second input port and the second output port of the negative pressure heat exchanger are connected in series to the first intake gas pipeline.

3. The platform for horizontal temperature testing of a radio frequency superconducting cavity according to claim 2, characterized in that, The first return gas pipeline is provided with a sixteenth low-temperature valve, a fifth pressure sensor and a sixth temperature sensor. Among them, the sixth temperature sensor is located between the sixteenth low-temperature valve and the fifth pressure sensor; the second return gas pipeline is provided with a thirteenth low-temperature valve, a sixth pressure sensor and a seventh temperature sensor. Among them, the seventh temperature sensor is located between the thirteenth low-temperature valve and the sixth pressure sensor; the third return gas pipeline is provided with a tenth low-temperature valve, an eleventh low-temperature valve, a first pressure sensor, a second pressure sensor, a first temperature sensor, a second temperature sensor and an eighth temperature sensor. Among them, the eleventh low-temperature valve is located between the eighth temperature sensor and the first output port of the negative pressure heat exchanger, the first temperature sensor and the first pressure sensor are located between the eleventh low-temperature valve and the first output port of the negative pressure heat exchanger, and the second pressure sensor and the second temperature sensor are located between the tenth low-temperature valve and the first input port of the negative pressure heat exchanger; the first intake pipeline is provided with a sixth low-temperature valve, a third pressure sensor, a fourth pressure sensor, a third temperature sensor and a fourth temperature sensor. Among them, the fourth pressure sensor and the fourth temperature sensor are located between the sixth low-temperature valve and the second output port of the negative pressure heat exchanger, and the third temperature sensor is located between the third pressure sensor and the second input port of the negative pressure heat exchanger; the second intake pipeline is provided with a ninth low-temperature valve, a seventh pressure sensor and a fifth temperature sensor. Among them, the seventh pressure sensor is located between the ninth low-temperature valve and the fifth temperature sensor.

4. The platform for horizontal temperature test of the radio frequency superconducting cavity according to claim 3, characterized in that, The first return gas pipeline between the sixth temperature sensor and the sixteenth low-temperature valve is communicated with the cooling return gas pipeline of the distribution transmission system through a fifteenth low-temperature valve; the second return gas pipeline between the seventh temperature sensor and the thirteenth low-temperature valve is communicated with the cooling return gas pipeline of the distribution transmission system through a fourteenth low-temperature valve; the third return gas pipeline between the eleventh low-temperature valve and the first pressure sensor is communicated with the cooling return gas pipeline of the distribution transmission system through a twelfth low-temperature valve.

5. The platform for horizontal temperature test of the radio frequency superconducting cavity according to claim 3, characterized in that, The multiple intake pipelines further include: A third intake pipeline, the input end of the third intake pipeline is communicated with the first intake pipeline between the third pressure sensor and the third temperature sensor, and the output end of the third intake pipeline is communicated with the input end of the corresponding thermostat; the third intake pipeline is provided with a seventh low-temperature valve, an eighth pressure sensor and a ninth temperature sensor, and the eighth pressure sensor is located between the seventh low-temperature valve and the ninth temperature sensor; A fourth intake pipeline, the input end of the fourth intake pipeline is communicated with the first intake pipeline between the third pressure sensor and the third temperature sensor, and the output end of the fourth intake pipeline is communicated with the input end of the corresponding thermostat; the fourth intake pipeline is provided with an eighth low-temperature valve.

6. The platform for horizontal temperature measurement of a radio frequency superconducting cavity according to claim 5, characterized in that, A first temperature mixer is provided in the second intake pipeline between the ninth cryogenic valve and the seventh pressure sensor, and an input end of the first temperature mixer is communicated with a rewarming air supply pipeline of the distribution and transmission system through a sixth normal temperature pneumatic valve; A second temperature mixer is provided in the third intake pipeline between the eighth pressure sensor and the seventh cryogenic valve. The second temperature mixer is sequentially communicated with the rewarming air supply pipeline of the distribution and transmission system through a second one-way valve and a seventh normal temperature pneumatic valve. A tenth pressure sensor and a switch valve are provided on the rewarming air supply pipeline of the distribution and transmission system.

7. The platform for horizontal temperature testing of a radio frequency superconducting cavity according to claim 5, characterized in that, The first return air pipeline is communicated with a recovery and purification system through a first connecting pipeline. A third primary safety valve and a third bursting disc are provided on the first connecting pipeline. The first connecting pipeline between the third bursting disc and the first return air pipeline is communicated with the displacement pump set through a third normal temperature pneumatic valve; the second return air pipeline is communicated with the recovery and purification system through a second connecting pipeline. A second primary safety valve and a second bursting disc are provided on the second connecting pipeline; the second connecting pipeline between the second bursting disc and the second return air pipeline is communicated with the displacement pump set through a second normal temperature pneumatic valve; The platform includes a first negative pressure protection and safety relief integrated device and a second negative pressure protection and safety relief integrated device. An air inlet of the first negative pressure protection and safety relief integrated device is communicated with the third return air pipeline through a first one-way valve. An air supply port of the negative pressure protection and safety relief integrated device of the first negative pressure protection and safety relief integrated device is communicated with a low-pressure circuit branch of the refrigeration system of the distribution and transmission system. A displacement air outlet of the first negative pressure protection and safety relief integrated device is communicated with the displacement pump set through a fourth normal temperature pneumatic valve; a recovery and purification air outlet of the first negative pressure protection and safety relief integrated device is communicated with the recovery and purification system; a pressure relief air outlet of the first negative pressure protection and safety relief integrated device is communicated with a first bursting disc through a first secondary safety valve; An air inlet of the second negative pressure protection and safety relief integrated device is communicated with the thermostat. An air supply port of the negative pressure protection and safety relief integrated device of the second negative pressure protection and safety relief integrated device is communicated with a low-pressure circuit branch of the refrigeration system of the distribution and transmission system. A displacement air outlet of the second negative pressure protection and safety relief integrated device is communicated with the displacement pump set through a fifth normal temperature pneumatic valve; a recovery and purification air outlet of the second negative pressure protection and safety relief integrated device is communicated with the recovery and purification system. A pressure relief air outlet of the second negative pressure protection and safety relief integrated device is communicated with a fourth bursting disc through a fourth secondary safety valve.

8. A system for horizontal temperature testing of a radio frequency superconducting cavity, characterized in that, The system includes a helium storage system, a refrigeration system, a distribution and transmission system, a superfluid helium acquisition system, a recovery and purification system, a control integration system, and a platform for horizontal temperature testing of a radio frequency superconducting cavity according to any one of claims 1 to 7.

9. A method of using a system for horizontal temperature measurement of a radio frequency superconducting cavity, the method being based on the system for horizontal temperature measurement of a radio frequency superconducting cavity according to claim 8, characterized in that, Including: Step S1, the equipment evacuates the horizontal test valve box through the horizontal test valve box vacuum and evacuates the thermostat through the thermostat vacuum, so as to maintain the horizontal test valve box and the thermostat in a vacuum state of the order of 1×10 -4 Pa; Step S2: Open the sixth to sixteenth cryogenic valves, the first to fifth normal-temperature pneumatic valves, and the displacement pump group to evacuate the distribution and transmission system, multiple return gas pipelines and multiple intake gas pipelines in the horizontal test valve box; obtain the values of the first to ninth pressure sensors. When the maximum value among the values of the first to ninth pressure sensors is lower than 100 Pa, close the displacement pump group and the first to fifth normal-temperature pneumatic valves; then open the switch valve, the sixth normal-temperature pneumatic valve, and the seventh normal-temperature pneumatic valve, and slowly fill helium gas at 300 K into the pipeline. When the maximum value among the values of the first to ninth pressure sensors reaches 1.5 bar, close the switch valve, the sixth normal-temperature pneumatic valve, and the seventh normal-temperature pneumatic valve, and let it stand for the first predetermined time; Step S3: Repeat Step S2 multiple times to ensure the replacement effect; Step S4: Open the ninth cryogenic valve and the fifteenth cryogenic valve, and maintain the opening of the fifteenth cryogenic valve above 90%. Gradually increase the opening of the second cryogenic valve and the ninth cryogenic valve to cool the cold shield assembly of the horizontal test valve box and the cryostat. Obtain the value of the sixth temperature sensor. When the value of the sixth temperature sensor stabilizes at 75 K, open and slowly and gradually increase the opening of the sixteenth cryogenic valve, and slowly close the fifteenth cryogenic valve; Step S5: Open the first cryogenic valve and the fourteenth cryogenic valve, then open the seventh cryogenic valve, and gradually increase the opening of the seventh cryogenic valve to prepare liquid helium at 4.5 K @ 1.3 bar; at the same time, open the sixth cryogenic valve and maintain a small opening to cool the negative pressure heat exchanger; Step S6: Control the opening of the seventh cryogenic valve so that the value of the 4.5 K liquid helium level gauge in the cryostat is 95%, and limit the minimum opening adjustment of the seventh cryogenic valve to 10%; Step S7: Open the 2K gas heater of the superfluid helium acquisition system and preheat for the second predetermined time to fully activate the heater; Step S8: Open the superfluid helium decompression and cooling pump group of the superfluid helium acquisition system, slowly close the seventh cryogenic valve, close the fourteenth cryogenic valve, and then slowly open the thirteenth cryogenic valve; gradually increase the opening of the sixth cryogenic valve to start throttling and decompression to obtain superfluid helium at 2K @ 0.03 bar; Step S9: When the liquid helium at 4.5 K @ 1.3 bar in the cryostat is transformed into superfluid helium at 2K @ 0.03 bar, adjust the opening of the sixth cryogenic valve so that the value of the 2K superfluid helium level gauge is 95%, conduct a 2K test, and then adjust the minimum opening of the sixth cryogenic valve to 10%; Step S10: After the test is completed, open the fourteenth cryogenic valve, close the thirteenth cryogenic valve and the superfluid helium acquisition system, and slowly close the first cryogenic valve and the second cryogenic valve to stop supplying cold to the horizontal test valve box and the cryostat; Step S11: Turn on the solid-contact DC power heater inside the thermostat and control the power of the solid-contact DC power heater within a predetermined range; when the value of the temperature sensor around the solid-contact DC power heater reaches 70K, turn off the solid-contact DC power heater; Step S12: Open the switch valve, the fifth normal-temperature pneumatic valve, and the sixth normal-temperature pneumatic valve, and input 300K normal-temperature helium gas into the horizontal test valve box and the thermostat to accelerate the rewarming speed; Step S13: When the value of the temperature sensor around the solid-contact DC power heater reaches normal temperature, turn off the vacuum pump sets of the horizontal test valve box vacuum acquisition device and the thermostat vacuum acquisition device.

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