Apparatus and method for measuring specific heat of water-cooled magnets in low-temperature environments under strong magnetic fields

Abstract

This invention provides an apparatus and method for measuring specific heat under low-temperature conditions in a strong magnetic field of a water-cooled magnet, belonging to the technical field of specific heat measurement under strong magnetic field conditions in water-cooled magnets. The apparatus includes: a sample fixing part for fixing the sample to be measured; a heater disposed on the sample fixing part for heating the sample; a temperature sensor disposed on the sample fixing part for measuring the temperature of the sample; a connecting part, one end of which is connected to the sample fixing part; a signal conversion part connected to the other end of the connecting part; a signal line passing through the sample fixing part and the signal conversion part, one end of which is connected to the heater and the temperature sensor, and the other end is used to connect to an external device through the signal conversion part; and a heat sink connected between the sample fixing part and the connecting part, the heat sink having an inlet and an outlet for the signal line to enter or exit the sample fixing part through the heat sink.

Description

Technical Field

[0001] This invention relates to the field of specific heat measurement technology in the context of strong magnetic field environments of water-cooled magnets, and specifically to an apparatus and method for measuring specific heat in the context of low-temperature environments under strong magnetic field conditions of water-cooled magnets. Background Technology

[0002] Specific heat is one of the most important thermophysical properties of solid materials, and the study of low-temperature specific heat measurement systems has always been a topic of great interest. The strong magnetic field of a steady-state water-cooled magnet is an important experimental condition in condensed matter physics. The electronic structure of most materials studied in condensed matter physics changes under extreme conditions such as strong magnetic fields, high pressure, and low temperatures. Specific heat measurement under strong magnetic fields is an important means of studying the intrinsic mechanisms of these changes. However, current technology lacks methods and related devices for measuring the specific heat of materials under strong magnetic fields of water-cooled magnets. Summary of the Invention

[0003] The purpose of this invention is to provide an apparatus and method for measuring the specific heat of a material in a strong magnetic field and low temperature environment of a water-cooled magnet. This apparatus and method can determine the specific heat of a material in a strong magnetic field environment of a water-cooled magnet.

[0004] To achieve the above objectives, embodiments of the present invention provide a device for measuring specific heat in a low-temperature environment under a strong magnetic field of a water-cooled magnet, comprising:

[0005] The sample fixing part is used to fix the sample to be tested;

[0006] A heater, disposed on the sample fixing part, is used to heat the sample;

[0007] A temperature sensor is mounted on the sample fixing part and is used to measure the temperature of the sample;

[0008] A connecting part, one end of which is connected to the sample fixing part;

[0009] The signal adapter is connected to the other end of the connecting part;

[0010] A signal line is provided through the sample fixing part and the signal conversion part, and one end of the signal line is connected to the heater and the temperature sensor, and the other end is used to connect to an external device through the signal conversion part;

[0011] A heat sink is connected between the sample fixing part and the connecting part. The heat sink is provided with an inlet and an outlet for signal lines to enter or exit the sample fixing part through the heat sink.

[0012] Optionally, the sample fixing part includes:

[0013] A sapphire mounting stage is provided at the end of the sapphire mounting stage away from the connecting part. The mounting groove is used to fix the sample. The heater and temperature sensor are fixed to the bottom of the mounting groove by suspension wires.

[0014] A metal base is connected to the connecting part and the sapphire mounting platform.

[0015] Optionally, the sample fixing part includes:

[0016] A metal sleeve is fitted around the sapphire mounting base.

[0017] Optionally, the device further includes a heat sink connected between the sample fixing part and the connecting part. The heat sink is provided with an inlet and an outlet for the signal lines to enter or exit the sample fixing part through the heat sink.

[0018] Optionally, the connecting part includes a connecting rod and a radiating plate spaced apart, and the connecting rod is a hollow rod, and the connection between the connecting rod and the radiating plate is an airtight connection.

[0019] Optionally, the signal line includes at least 16 phosphor bronze wires, at least 2 constantan wires, and a fixing hose. Each pair of the at least 16 phosphor bronze wires and each pair of the at least 2 constantan wires are twisted together to form a signal line pair. Six pairs of signal lines form one group of the signal line, and two pairs of signal lines and one pair of constantan wires form another group of the signal line. The fixing hose is used to fix one group and the other group of the signal line respectively, and the fixing hose is provided with at least four vent holes.

[0020] Optionally, the signal adapter includes a square body, with flanges on at least three sides of the square body to facilitate external connections, and a ball valve on at least one side of the square body.

[0021] On the other hand, the present invention also provides a method for measuring specific heat in a low-temperature environment with a strong magnetic field of a water-cooled magnet, the method comprising:

[0022] Fix the sample onto any of the devices described above;

[0023] The device is evacuated via a signal converter.

[0024] The device, after being evacuated, is inserted into the strong magnetic field of a water-cooled magnet, and the position of the sample fixing part within the strong magnetic field of the water-cooled magnet is cooled.

[0025] The heater of the device in the strong magnetic field of the water-cooled magnet is activated by the signal line to heat the sample to a predetermined temperature with a constant power, and the temperature data of the sample is collected at the same time.

[0026] Stop heating and receive the temperature data of the sample in real time via a temperature sensor;

[0027] The sample specific heat is obtained based on the temperature data.

[0028] Optionally, obtaining the sample specific heat based on the temperature data specifically includes:

[0029] The specific heat of the temperature-changing device in the sample fixing part with the sample fixed and the specific heat of the temperature-changing device without the sample fixed were measured using a preset specific heat measurement method.

[0030] The specific heat of the temperature-controlled device with the sample fixed is subtracted from the specific heat of the temperature-controlled device without the sample fixed to obtain the specific heat of the sample.

[0031] The specific heat measurement method includes:

[0032] Pre-calibration of the thermal conductivity κ between the temperature-changing device and the temperature-controlled device s Thermal conductivity is calculated according to formula (1).

[0033]

[0034] A constant power is applied to the sample, and the sample temperature rises from T0 to T. The thermal conductivity κ is obtained by dividing the power P by the change in sample temperature. s ;

[0035] By changing the power and repeating the above steps, the thermal conductivity κ between the variable-temperature device and the constant-temperature device at different temperatures T can be obtained. s ;

[0036] The system's heat balance equation is constructed based on formula (2).

[0037]

[0038] Among them, C t C is the specific heat of the system, C' is the specific heat of the sample, C′ is the specific heat of the sample fixing part, P′ is the heating power, T is the temperature of the system, and κ is the specific heat of the sample fixing part. s T0 is the thermal conductivity between the constant temperature device and the variable temperature device inside the sample fixing part at temperature T, and T0 is the constant temperature of the constant temperature device.

[0039] The exponential decay cooling of the sample is determined according to formula (3).

[0040] T-T0=ΔTexp(-t / τ1), (3)

[0041] Where τ1 is the time constant and ΔT is the temperature difference;

[0042] The specific heat of the system is determined according to formula (4).

[0043] C t =κ s ·τ1, (4).

[0044] Optionally, obtaining the sample specific heat based on the temperature data specifically includes:

[0045] The specific heat of the temperature-changing device in the sample fixing part with the sample fixed and the specific heat of the temperature-changing device without the sample fixed were measured using a preset specific heat measurement method.

[0046] The specific heat of the temperature-controlled device with the sample fixed is subtracted from the specific heat of the temperature-controlled device without the sample fixed to obtain the specific heat of the sample.

[0047] The specific heat measurement method includes:

[0048] The specific heat of the sample is obtained according to formulas (5) to (7).

[0049]

[0050]

[0051]

[0052] Where C(T) is the specific heat of the system, and T h (T) represents the temperature of the sample corresponding to the temperature rise curve, P h (T) represents the heating power, T c (T) represents the temperature of the sample corresponding to the temperature decrease curve, P l (T) represents power loss, P p (T) represents the parasitic power.

[0053] Through the above technical solution, the device and method for measuring the specific heat of a water-cooled magnet in a strong magnetic field at low temperature provided by the present invention fixes the sample with a sample fixing part, and extends the sample into the magnetic field by combining a heat sink and a connecting part. Finally, the sample is heated and its temperature is measured by a signal line, a heater and a temperature sensor, thereby realizing the measurement of the specific heat of the sample in a water-cooled magnet in a strong magnetic field at low temperature.

[0054] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0055] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0056] Figure 1 This is a schematic diagram of a device for measuring specific heat of a water-cooled magnet in a low-temperature environment under a strong magnetic field, according to an embodiment of the present invention.

[0057] Figure 2 This is a schematic diagram of a sapphire mounting stage according to an embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of a metal base according to one embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of a metal sleeve according to an embodiment of the present invention;

[0060] Figure 5 This is a schematic diagram of a heat sink according to an embodiment of the present invention;

[0061] Figure 6 This is a schematic diagram of a connection portion according to an embodiment of the present invention;

[0062] Figure 7 This is a schematic diagram of a signal switching section according to an embodiment of the present invention;

[0063] Figure 8 This is a flowchart of a method for measuring specific heat of a water-cooled magnet in a low-temperature environment under a strong magnetic field, according to an embodiment of the present invention.

[0064] Explanation of reference numerals in the attached figures

[0065] 1. Sample fixing part; 2. Connecting part

[0066] 3. Signal transceiver 4. Heat sink

[0067] 1-1. Sapphire mounting platform; 1-2. Metal base

[0068] 1-3, Metal sleeve; 2-1, Connecting rod

[0069] 2-2, Radiation sheet; 3-1, Square main body

[0070] 3-2, Flange; 3-3, Ball Valve

[0071] 4-1. Cable inlet; 4-2. Cable outlet Detailed Implementation

[0072] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0073] like Figure 1The diagram shows a schematic of an apparatus for measuring specific heat of a water-cooled magnet in a low-temperature environment under a strong magnetic field, according to an embodiment of the present invention. Figure 1 The device may include a sample fixing part 1, a heater, a temperature sensor, a connecting part 2, a signal transducer 3, a signal line, and a heat sink 4. The sample fixing part 1 is used to fix the sample to be tested. The heater is disposed on the sample fixing part 1 for heating the sample. The temperature sensor is disposed on the sample fixing part 1 for measuring the temperature of the sample. One end of the connecting part 2 can be connected to the sample fixing part 1. The signal transducer 3 can be connected to the other end of the connecting part 2. The signal line can be disposed through the sample fixing part 1 and the signal transducer 3, and one end of the signal line can be connected to the heater and the temperature sensor, while the other end can be used to connect to an external device via the signal transducer 3.

[0074] In such Figure 1 When the device shown is in operation, the sample fixing part 1 is used to fix the sample. Regarding the specific form and structure of the sample fixing part 1, provided that the basic function of fixing the sample is guaranteed, the sample fixing part 1 can be of various types known to those skilled in the art, such as bracket fixing, tray fixing, etc. However, considering that the specific heat measured by the device provided by this invention is in a water-cooled magnet strong magnetic field and low-temperature environment, in order to avoid the sample fixing part 1 being affected by the magnetic field and causing interference to the sample, in one example of this invention, the structure of the sample fixing part 1 can be as follows: Figure 2 and Figure 3 As shown. In Figure 2 and Figure 3In this embodiment, the sample fixing part 1 may further include a sapphire fixing stage 1-1 and a metal base 1-2. The end of the sapphire fixing stage 1-1 away from the connecting part 2 may be provided with a mounting groove 1-1-1. This mounting groove 1-1-1 can be used to fix the sample, and the heater and temperature sensor can be fixed below the mounting groove 1-1-1 via suspension wires. Regarding the specific arrangement of the heater and temperature sensor, in one example of the invention, a sapphire sheet can be used, with the temperature sensor and heater bonded to one side and the sample bonded to the other side. The suspension wire used to fix the sapphire sheet can also be a rigid suspension wire, which can avoid measurement errors caused by external vibrations. Furthermore, to ensure a good thermal connection between the sample and the sapphire, and to facilitate sample fixing, in this example, N-grease adhesive can be used to attach the sample to the mounting groove 1-1-1 (or onto the sapphire sheet). The metal base 1-2 can be connected to the connecting part 2 and the sapphire fixing stage 1-1 (e.g., via bolts). Sapphire is composed of aluminum oxide (Al₂O₃), which consists of three oxygen atoms and two aluminum atoms bonded together by covalent bonds, and its crystal structure is hexagonal. Commonly used facets include A-Plane, C-Plane, and R-Plane. Due to its wide optical transmission band, exhibiting excellent light transmittance from near-ultraviolet (190nm) to mid-infrared, sapphire is widely used in optical components, infrared devices, high-strength laser lens materials, and photomask materials. It possesses characteristics such as high acoustic velocity, high temperature resistance, corrosion resistance, high hardness, high light transmittance, and a high melting point (2045 degrees Celsius). These physical properties of sapphire allow the sapphire fixing stage 1-1 to isolate the electromagnetic eddy currents generated by the metal base 1-2 in a changing magnetic field, preventing these eddy currents from affecting the sample. Furthermore, to further prevent the sample from contacting the coil during insertion and to ensure the airtightness of the surrounding environment, in this example, the sample fixing part 1 may also include a metal sleeve 1-3, such as... Figure 4 As shown. The metal sleeve 1-3 can be fitted around the sapphire mounting stage 1-1. For ease of installation, the metal sleeve 1-3 can be directly connected to the metal base 1-2, thus ensuring that the entire sapphire mounting stage 1-1 is covered. Regarding the specific connection method between the metal sleeve 1-3 and the metal base 1-2, in one example of the present invention, it can be a threaded connection. Furthermore, to ensure the airtightness of the connection, vacuum silicone grease can be used to seal any gaps in the threads during installation.

[0075] The heat sink 4 can be connected between the sample fixing part 1 and the connecting part 2. The structural schematic diagram of the heat sink 4 can be as follows: Figure 5As shown. Since the device provided by this invention is for testing specific heat in a strong magnetic environment, two necessary environmental conditions are required: firstly, a vacuum environment, mainly to avoid excessive heat leakage caused by gas affecting the measurement; secondly, low temperature, because measuring specific heat requires observing the changes of the sample within a relatively wide temperature range, thus requiring the sample's environment to be lowered to a low temperature state (e.g., 1.6K). However, a low temperature state reduces the gas diffusion rate, thus affecting the vacuuming process; conversely, in a high vacuum environment, due to the lack of gas heat conduction, the heat exchange between the inside and outside is also slower, which also restricts the cooling and heating processes. Therefore, in the device provided by this invention, the sample fixing part 1 and the connecting part 2 are connected by a heat sink 4. Secondly, since the sample fixing part 1 is still in a low temperature environment, the device provided by this invention also provides activated carbon inside the metal sleeve 1-3. Since activated carbon itself can adsorb gas molecules, it can adsorb the remaining gas after vacuuming, thereby achieving the effect of improving the vacuum degree. Furthermore, activated carbon not only adsorbs residual gas within the rod, thus increasing the vacuum level, but also, as the activated carbon's temperature rises, its ability to adsorb gas molecules decreases, releasing a certain amount of gas molecules and thus lowering the vacuum level. Based on this characteristic, the activated carbon can be heated while waiting for the sample temperature to drop, releasing gas molecules (such as inert gases like helium) and reducing the vacuum level. At lower vacuum levels, due to the thermal conductivity of gas molecules, the sample temperature drops significantly faster than in a complete vacuum state when collecting temperature data, which also accelerates temperature data acquisition and improves experimental efficiency. Water-cooled magnets are expensive to operate and time is limited. Therefore, for samples with particularly high specific heat, low thermal conductivity, and long relaxation times, heating the activated carbon can adjust the gas pressure within the specific heat measurement rod, thereby shortening the relaxation time.

[0076] In one example of the present invention, for the convenience of connecting signal lines, such as Figure 5As shown, the heat sink 4 can also be provided with an inlet 4-1 and an outlet 4-2. When the device is working, because the metal sleeve 1-3 is in a vacuum state, there is a lack of gas for heat conduction, resulting in a long temperature drop time for the sample, leading to excessively long waiting times for the measurement conditions to be met. However, through the inlet 4-1 and outlet 4-2, the signal line can act as a temperature transfer medium to directly guide the internal heat to the outside of the device (i.e., guide the cold energy inside the magnet cavity to the inside of the device), greatly reducing waiting time and improving experimental efficiency. Furthermore, regarding the size of the heat sink 4, in one example of the present invention, the heat sink 4 can be a copper sleeve with a length of 40 mm, an inner diameter of 8.2 mm, and an outer diameter of 10.2 mm. The copper sleeve has at least two through-holes along any one of the generatrice directions, namely the inlet 4-1 and the outlet 4-2. When installing the circuitry, considering the effect of vacuuming, Stycast adhesive can also be used to seal the gaps between the circuitry and the through-holes.

[0077] The connecting part 2 connects the signal transceiver part 3 and the sample fixing part 1, thereby facilitating the insertion of the sample into the strong magnetic field of the water-cooled magnet. While the specific form of this connecting part 2 can be varied and known to those skilled in the art, considering the need to maintain the low temperature of the sample fixing part 1, the connecting part 2 can be as follows: Figure 6 The structure shown is described. In this... Figure 6 In this design, the connecting part 2 may include a connecting rod 2-1 and a radiating plate 2-2 spaced apart. The connecting rod 2-1 is a hollow rod used to extend the insertion depth of the sample. The radiating plate 2-2 is designed to further shield the sample area from external temperature influences due to the relatively poor thermal conductivity of the connecting rod 2-1, thus ensuring the stability of the experiment. Therefore, the device isolates the thermal conductivity of the connecting rod 2-1 by spaced-aparting the radiating plate 2-2 from the connecting rod 2-1. Furthermore, to ensure that the arrangement of the radiating plate 2-2 and the connecting rod 2-1 does not affect the vacuuming operation, the connection between them can be airtight. Specifically, this airtight connection can be achieved by configuring the radiating plate 2-2 as two symmetrical semi-circular structures with threaded holes. The two semi-circular structures merge together to enclose the connecting rod 2-1, and finally the two semi-circular structures are fastened together by bolts and threaded holes.

[0078] The signal line is used to connect the heater, temperature sensor, and signal converter 3. While the specific form of this signal line can be varied and known to those skilled in the art, considering that a large current flows through the signal line itself when the heater is started, to avoid electromagnetic noise generated by a large current (e.g., a large current in a water-cooled magnet) in the signal path 6, in one example of the invention, the signal line may include at least 16 phosphor bronze wires, at least 2 constantan wires, and a fixing hose. Each pair of the at least 16 phosphor bronze wires and each pair of the at least 2 constantan wires can be twisted to form a signal wire pair. Six pairs of signal wires form one group of the signal line, and two pairs of signal wires and one pair of constantan wires form another group of the signal line. The fixing hose is used to fix one group and the other group of the signal line respectively, and the fixing hose is provided with at least four vent holes. Furthermore, the solid hose needs to be straightened directly within the connecting rod 2-1, and at least four supports are provided within the connecting rod to fix the solid hose. This is because water-cooled magnets vibrate significantly in a strong magnetic field environment. This fixing method can reduce the vibration of the circuit and thus avoid increasing noise.

[0079] The signal adapter 3 can be used to allow external devices to connect to the vacuum pump and signal line interface. While the specific form of this signal adapter 3 can be varied and known to those skilled in the art, it is considered that during the vacuuming process, the signal line also needs to connect to the heater and temperature sensor. Therefore, in one example of the present invention, the signal adapter 3 may include, for example... Figure 7 The structure shown is described. In this... Figure 4 The signal adapter may include a square body 3-1. Flanges 3-2 may be provided on three sides of the square body 3-1. Through these flanges 3-2, signal lines can be connected to external signal line connectors. Furthermore, a ball valve 3-3 may be provided on at least one side of the square body 3-1. Through this ball valve 3-3, a vacuum pump can evacuate the device.

[0080] On the other hand, the present invention also provides a method for measuring specific heat in a water-cooled magnet under low-temperature conditions with a strong magnetic field. This method may include, for example... Figure 8 The steps are shown. In this Figure 8 In this context, the method may include:

[0081] In step S10, a device as described above with a sample fixed thereon and a device as described above without a sample fixed thereon are respectively set up;

[0082] In step S11, the device is evacuated via the signal transfer unit;

[0083] In step S12, the device after the vacuuming operation is inserted into the strong magnetic field of the water-cooled magnet, and the position of the sample fixing part in the strong magnetic field of the water-cooled magnet is cooled down.

[0084] In step S13, the heater of the device in the strong magnetic field of the water-cooled magnet is activated through the signal line to heat the sample to the predetermined temperature with a constant power, and the temperature data of the sample is collected at the same time.

[0085] In step S14, heating is stopped, and the temperature data of the sample is received in real time through a temperature sensor;

[0086] In step S15, the specific heat of the sample is obtained based on the temperature data.

[0087] In such Figure 8 In the method shown, step S10 is used to set up the apparatus as described above with the sample fixed and the apparatus as described above without the sample fixed. Step S11 may be to perform a vacuuming operation (using a vacuum pump) on the apparatus via a signal converter (in this embodiment, the vacuum level is at least 10). -3 Step S12 also cools the sample fixing point (typically to 1.6 K), thus providing external low-temperature conditions for the specific heat test. Step S13 may activate the heater of the device in the strong magnetic field of the water-cooled magnet via a signal line. Simultaneously, combined with step S14, the sample is heated and cooled, and temperature data of the sample changing over time is determined by observing the temperature during the heating and cooling processes (acquisition time is generally less than 10 minutes). Specifically, this temperature data can be acquired from the start of heating. More specifically, the sample can be heated at a constant power, and the temperature change of the sample can be acquired simultaneously with heating. Similarly, after heating stops, the temperature change of the sample can be acquired in real time. Finally, the temperature changes of the two processes are summarized into this temperature data.

[0088] Finally, the specific heat of the sample is calculated based on the temperature data in step S15. It is worth noting that when measuring the sample's temperature data in steps S13 and S14, the principle of the controlled variable method can also be used, changing the strength of the magnetic field to obtain the temperature curves of the sample under different magnetic field intensities.

[0089] While the method for obtaining the sample specific heat in step S15 can take many forms known to those skilled in the art, in one example of the present invention, the method may involve first measuring the specific heat of the temperature-changing device within the sample fixing part where the sample is fixed and the specific heat of the temperature-changing device without the sample fixed using a preset specific heat measurement method. Then, the specific heat of the temperature-changing device with the sample fixed and the specific heat of the temperature-changing device without the sample fixed are subtracted to obtain the sample specific heat. Wherein, if the sample fixing part includes a sapphire fixing stage 1-1 and a metal base 1-2, the sapphire fixing stage 1-1 (excluding the sample mounting slot 1-1-1 portion) and the metal base 1-2 can be constant-temperature devices, while the sample mounting slot 1-1-1 on the sapphire fixing stage can be a temperature-changing device. In one example of the present invention, the preset specific heat measurement method may involve first calibrating the thermal conductivity κ between the temperature-changing device and the constant-temperature device. s Thermal conductivity is calculated according to formula (1).

[0090]

[0091] A constant power is applied to the sample, and the sample temperature rises from T0 to T. The thermal conductivity κ is obtained by dividing the power P by the change in sample temperature. s ;

[0092] Change the power level and repeat the above steps (i.e., increase the sample temperature from T0 to T, and divide the power P by the change in sample temperature to obtain the thermal conductivity κ). s This allows us to obtain the thermal conductivity κ between the variable-temperature device and the constant-temperature device at different temperatures T. s .

[0093] The system's heat balance equation is constructed based on formula (2).

[0094]

[0095] Among them, C t C is the specific heat of the system, C' is the specific heat of the sample, C′ is the specific heat of the sample fixing part, P′ is the heating power, T is the temperature of the system, and κ is the specific heat of the sample fixing part. s T is the thermal conductivity between the constant temperature device and the variable temperature device inside the sample fixing part at temperature T, and T0 is the constant temperature of the part of the connecting part that is connected to the sample fixing part.

[0096] Then, the exponential decay cooling of the sample is determined according to formula (3).

[0097] T-T0=ΔTexp(-t / τ1), (3)

[0098] Where τ1 is the time constant;

[0099] Finally, the specific heat of the system is determined according to formula (4).

[0100] C t =κ s ·τ1, (4).

[0101] In another example of the present invention, the specific heat measurement method can also be to obtain the sample specific heat according to formulas (5) to (7).

[0102]

[0103]

[0104]

[0105] Where C(T) is the specific heat of the system, and T h (T) represents the temperature of the sample corresponding to the temperature rise curve, P h (T) represents the heating power, T c (T) represents the temperature of the sample corresponding to the temperature decrease curve, P l (T) represents power loss, P p (T) represents the parasitic power.

[0106] Through the above technical solution, the device and method for measuring the specific heat of a water-cooled magnet in a strong magnetic field at low temperature provided by the present invention fixes the sample with a sample fixing part, and extends the sample into the magnetic field by combining a heat sink and a connecting part. Finally, the sample is heated and its temperature is measured by a signal line, a heater and a temperature sensor, thereby realizing the measurement of the specific heat of the sample in a water-cooled magnet in a strong magnetic field at low temperature.

[0107] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0108] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0109] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0110] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0111] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0112] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0113] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0114] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0115] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An apparatus for specific heat measurement of a water-cooled magnet in a high magnetic field and low temperature environment, characterized by, The device comprises: a sample fixing part for fixing a sample to be measured; a heater arranged on the sample fixing part for heating the sample; a temperature sensor arranged on the sample fixing part for measuring the temperature of the sample; a connecting part, one end of which is connected with the sample fixing part; a signal adapter connected with the other end of the connecting part; a signal line arranged through the sample fixing part and the signal adapter, one end of which is connected with the heater and the temperature sensor, and the other end of which is used for connecting to an external device through the signal adapter; a heat sink connected between the sample fixing part and the connecting part, the heat sink being provided with an inlet and an outlet for the signal line to enter or exit the sample fixing part through the heat sink; the sample fixing part comprises: a sapphire fixing table, an end of which away from the connecting part is provided with a mounting groove for fixing the sample, and the heater and the temperature sensor are fixed below the mounting groove through a suspension wire; a metal base connected with the connecting part and the sapphire fixing table; the connecting part comprises spaced connecting rods and radiation sheets, and the connecting rods are hollow rods, and the connection between the connecting rods and the radiation sheets is airtight connection; the heat sink is a red copper sleeve, the length of the red copper sleeve is 40 mm, the inner diameter is 8.2 mm, and the outer diameter is 10.2 mm; the signal line comprises at least 16 phosphor copper wires, at least 2 constantan wires, and a fixed hose, and each two of the at least 16 phosphor copper wires and each two of the at least 2 constantan wires are twisted to form a pair of signal lines, 6 pairs of signal lines form a group in the signal line, 2 pairs of signal lines and 1 pair of constantan wires form another group in the signal line, and the fixed hose is used for fixing the two groups respectively, and at least 4 air holes are arranged on the fixed hose.

2. The apparatus of claim 1, wherein, The sample fixing part comprises a metal sleeve which is sleeved on the periphery of the sapphire fixing table.

3. The apparatus of claim 1, wherein, The signal adapter comprises a square main body, flanges are arranged on at least three surfaces of the square main body to facilitate external connectors, and a ball valve is arranged on at least one surface of the square main body.

4. A method for specific heat measurement in a water-cooled magnet high magnetic field cryogenic environment, characterized by, The method comprises: respectively arranging a device as claimed in any one of claims 1 to 3 with a sample fixed therein and a device as claimed in any one of claims 1 to 3 without a sample fixed therein; performing a vacuumizing operation on the devices through the signal adapter; immersing the devices after the vacuumizing operation into a water-cooled magnet strong magnetic field, and cooling the position of the sample fixing part in the water-cooled magnet strong magnetic field; starting the heater of the device in the water-cooled magnet strong magnetic field through the signal line to heat the sample to a predetermined temperature at a constant power, and collecting temperature data of the sample at the same time; stopping heating, and receiving the temperature data of the sample in real time through the temperature sensor; obtaining the specific heat of the sample according to the temperature data.

5. The method of claim 4, wherein, The method for obtaining the specific heat of the sample according to the temperature data specifically comprises: respectively measuring the specific heat of a temperature changing device in a sample fixing part with a sample fixed therein and the specific heat of a temperature changing device without a sample fixed therein by using a preset specific heat measuring method; Subtract the specific heat of the temperature-variable device fixed with the sample from the specific heat of the temperature-variable device without the sample to obtain the sample specific heat; The specific heat measuring method comprises: Anticipating thermal conductance between variable and constant temperature devices The thermal conductance is calculated according to equation (1), ，（1） A constant power is applied to the sample and the temperature of the sample is raised from , , the power divided by the change in temperature of the sample gives the thermal conductivity ; Change the power size, repeat the above steps, that is, different temperature Thermal conductance between down-conversion device and constant temperature device ; A heat balance equation of the system is constructed according to formula (2), ， ，（2） wherein, Cp is the specific heat of the system, Cp is the specific heat of the sample, Cp is the specific heat of the sample holding section, P is the heating power, T is the temperature of the system, T is the temperature K is the thermal conductance between the constant temperature device and the variable temperature device in the sample holding section, Tc is the constant temperature of the constant temperature device; An exponential decay cooling condition of the sample is determined according to formula (3), ，（3） wherein is a time constant, is a temperature difference; The specific heat of the system is determined according to formula (4), ，（4）。 6. The method of claim 4, wherein, The sample specific heat of the sample is obtained according to the temperature data, and specifically comprises: The specific heat of the temperature-variable device in the sample fixed part fixed with the sample and the specific heat of the temperature-variable device without the sample are measured respectively by using a preset specific heat measuring method; Subtract the specific heat of the temperature-variable device fixed with the sample from the specific heat of the temperature-variable device without the sample to obtain the sample specific heat; The specific heat measuring method comprises: The sample specific heat is obtained according to formula (5) to formula (7), ，（5） ，（6） ，（7） wherein, Cp is the specific heat of the system, T is the temperature of the sample corresponding to the temperature rise curve, P is the heating power, T is the temperature of the sample corresponding to the temperature drop curve, Ploss is the power loss, Pparasitic is the parasitic power.

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