Superconducting magnet structure for magnetic control czochralski silicon and protection device

Abstract

The utility model belongs to the technical field of superconducting equipment, and discloses a superconducting magnet structure for magnetic control czochralski silicon and a protection device. The superconducting magnet structure comprises a magnetic shielding vacuum cavity, a cold shield, a superconducting coil fixing cylinder and four arc-shaped superconducting coils which are wound by an MgB2 superconducting material and are symmetrically distributed, the superconducting coils are arranged at a specific angle, and the magnetic field utilization rate and the mechanical stability are optimized. The protection device comprises a superconducting power supply, a programmable controller and an outer protection resistance box. The external protection resistance box adopts a structure that a plurality of sections of resistors are connected in parallel with a cut-off switch, the input resistance value can be accurately controlled by a programmable controller according to working current or quench signals, and hierarchical control of the energy release speed is realized. According to the utility model, the temperature rise after the MgB2 superconducting magnet is quenched is effectively reduced, the system recovery time is obviously shortened, and the reliability and the production efficiency of magnetic control czochralski silicon production equipment are improved.

Description

Technical Field

[0001] This utility model relates to the field of superconducting equipment technology, specifically to a superconducting magnet structure and protection device for magnetically controlled Czochralski single-crystal silicon. Background Technology

[0002] High-purity single-crystal silicon is a key basic material for the integrated circuit, semiconductor, and photovoltaic industries. Magnetron Czochralski (MCZ) is the mainstream technology for producing high-quality single-crystal silicon. It improves the purity and uniformity of the single crystal by applying a magnetic field during crystal growth to suppress thermal convection of molten silicon. Superconducting magnets are used in this field because they can generate strong magnetic fields.

[0003] Traditional MCZ superconducting magnets mostly use low-temperature superconducting materials such as niobium-titanium (NbTi), which require operation at liquid helium temperatures (4.2K), resulting in high cooling costs. In recent years, magnesium diboride (MgB2) superconducting materials have shown great application potential due to their higher superconducting transition temperature (approximately 39K) and lower cost, enabling them to operate at cryogenic temperatures of 10–20K, significantly reducing the difficulty of operation and maintenance.

[0004] However, quench propagation speed in MgB2 superconducting wires is slow, and heat dissipation after quench is insufficient, easily leading to localized overheating. This places higher demands on the speed and effectiveness of quench protection systems. Existing protection schemes are mostly passive segmented protection, and the time required for the magnet to cool and recover to the superconducting state after quench is long (usually exceeding 24 hours), seriously affecting the continuous operation capability of the equipment. Therefore, there is an urgent need for a superconducting magnet structure and protection device for magnetron-controlled Czochralski single-crystal silicon. Utility Model Content

[0005] The purpose of this invention is to provide a superconducting magnet structure and protection device for magnetically controlled Czochralski single-crystal silicon, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A superconducting magnet structure for magnetically controlled Czochralski-grown single-crystal silicon includes:

[0008] A magnetically shielded vacuum chamber, the interior of which is a vacuum-sealed environment;

[0009] A cold shield disposed inside the magnetically shielded vacuum cavity;

[0010] A superconducting coil fixing cylinder is set inside the cold screen;

[0011] In addition, at least four superconducting coils are fixed to the superconducting coil fixing cylinder by the outer arc pressure plate of the superconducting coil;

[0012] The superconducting coil is made of MgB2 superconducting material and is arc-shaped.

[0013] The at least four superconducting coils include a first coil, a second coil, a third coil, and a fourth coil that are symmetrically distributed in pairs in mechanical positions.

[0014] It also includes at least two refrigerators located at the top of the magnetically shielded vacuum chamber, which are used to cool the superconducting coils.

[0015] More preferably, the center angle between the first coil and the third coil is 108 degrees, and the center angle between the first coil and the second coil is 72 degrees.

[0016] More preferably, the refrigerator includes a first refrigerator and a second refrigerator, the first refrigerator and the second refrigerator being used to cool two adjacent superconducting coils respectively, wherein the first refrigerator is used to cool the first coil and the second coil, and the second refrigerator is used to cool the third coil and the fourth coil.

[0017] More preferably, a superconducting coil current lead is also provided through the top of the magnetically shielded vacuum cavity. The superconducting coil current lead includes a positive pole and a negative pole, which are electrically connected to the positive and negative poles of the superconducting coil main circuit, respectively.

[0018] More preferably, a cooling copper plate is provided between the first coil and the second coil, as well as between the third coil and the fourth coil, and the cooling copper plate is connected to the superconducting coil outer arc pressure plate on the first coil, the second coil, the third coil, and the fourth coil.

[0019] The inner arc surfaces of the first, second, third, and fourth coils are all in contact with the superconducting coil fixing cylinder, and the inner arc surfaces of the first, second, third, and fourth coils are all in contact with the outer arc pressure plate of the superconducting coil.

[0020] This utility model also provides a protective device for a superconducting magnet structure used in magnetically controlled Czochralski single-crystal silicon, comprising:

[0021] A superconducting power supply is electrically connected to the superconducting coil via a superconducting coil current lead;

[0022] A programmable controller connected to the superconducting power supply signal;

[0023] And an external protective resistor box electrically connected in the superconducting coil circuit;

[0024] The external protection resistor box includes a diode assembly, multiple protection resistors connected in series, and a disconnect switch connected in parallel with the protection resistors;

[0025] The programmable controller is configured to control the opening and closing of the disconnect switch to change the resistance value of the connected circuit.

[0026] More preferably, the protective resistor includes a first protective resistor, a second protective resistor, a third protective resistor, a fourth protective resistor, and a fifth protective resistor;

[0027] The disconnect switch includes a first disconnect switch, a second disconnect switch, a third disconnect switch, a fourth disconnect switch, and a fifth disconnect switch;

[0028] The first protective resistor is connected in series with the second, third, fourth, and fifth protective resistors arranged sequentially.

[0029] The first disconnect switch is connected in parallel across the second protective resistor;

[0030] The second disconnect switch is connected in parallel across the third protective resistor;

[0031] The third disconnect switch is connected in parallel across the fourth protective resistor;

[0032] The fourth disconnect switch is connected in parallel across the fifth protective resistor;

[0033] The fifth disconnect switch is connected in parallel across the series circuit of the second, third, fourth and fifth protective resistors;

[0034] The protective resistor is connected in series with a diode assembly at the end furthest from the disconnect switch. The diode assembly includes a first diode and a second diode connected in parallel, and a diode circuit breaker is connected in series in the circuit of the second diode.

[0035] More preferably, it also includes a quench detection circuit, which includes multiple voltage taps connected to the superconducting coil and a quench detector, the quench detector being connected to the programmable controller and the voltage taps respectively.

[0036] More preferably, a DC cut-off switch controlled by the programmable controller is provided on the circuit between the superconducting power supply and the superconducting coil;

[0037] When the quench detector detects a quench signal, the programmable controller is configured to perform the following operations:

[0038] The DC cut-off switch is controlled to open, thereby cutting off the power supply to the superconducting power source;

[0039] Control the corresponding cut-off switch action to connect the external protection resistor box to the circuit of the superconducting coil, so that the stored energy is transferred to the external resistor for dissipation.

[0040] More preferably, the programmable controller is configured to selectively close or open a corresponding cut-off switch when the quench detector detects a quench signal, based on the operating current value of the superconducting coil, so as to achieve graded control of the energy release rate.

[0041] Compared with the prior art, the beneficial effects of this utility model are:

[0042] High magnetic field utilization and stable structure: The four-coil structure with an arc shape arranged at a specific angle improves magnetic field uniformity and utilization while ensuring magnetic field strength, and improves the stress condition of the coil, reducing the risk of quenching caused by electromagnetic force during operation.

[0043] Low operating cost: Using MgB2 superconducting material, it can operate in the temperature range of the refrigerator (10-20K), eliminating the dependence on complex and expensive liquid helium refrigeration systems and significantly reducing refrigeration costs and maintenance difficulty.

[0044] Fast and effective quench protection: The innovative external protection resistor box, combined with a programmable controller, can intelligently switch resistors according to the current magnitude or quench state, achieving precise graded control of energy release rate. This allows for rapid transfer of energy stored in the magnet to external dissipation, greatly suppressing the temperature rise of the superconducting coil itself.

[0045] Recovery time is significantly shortened: Since the temperature rise of the coil after quench is effectively controlled, the heat load of the cooling system is reduced, and the magnet can cool back to the superconducting state more quickly, reducing the recovery time from more than 24 hours to less than a few hours, which greatly improves equipment availability and production efficiency.

[0046] High safety and reliability: The active quench detection and protection mechanism, combined with voltage limiting measures (such as diode components), avoids damage to the superconducting coil and insulation system caused by local overheating and excessive voltage, extends the service life of the equipment, and ensures the safety of personnel and equipment. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the overall structure of the superconducting magnet for magnetically controlled Czochralski-grown single-crystal silicon according to this utility model;

[0048] Figure 2 This is a schematic diagram of the internal structure of the superconducting magnet for magnetically controlled Czochralski-grown single-crystal silicon according to this utility model;

[0049] Figure 3 This is a schematic diagram of the circuit structure of the protection device of this utility model;

[0050] Figure 4 This is a schematic diagram of the overall circuit structure of the protection device of this utility model;

[0051] In the diagram: 101, Superconducting coil fixing cylinder; 102, Superconducting coil; 102A, First coil; 102B, Second coil; 102C, Third coil; 102D, Fourth coil; 103, Superconducting coil pressure plate; 104, Cold shield; 105, Magnetic shielding vacuum cavity; 106, Superconducting coil current lead; 106A, Positive electrode; 106B, Negative electrode; 107, Refrigeration unit; 107A, First refrigeration unit; 107B, Second refrigeration unit; 108, Voltage tap; 109, Cooling-conducting copper plate;

[0052] 2. Superconducting power supply;

[0053] 301. First protective resistor; 302. Second protective resistor; 303. Third protective resistor; 304. Fourth protective resistor; 305. Fifth protective resistor;

[0054] 401. Fifth disconnect switch; 402. First disconnect switch; 403. Second disconnect switch; 404. Third disconnect switch; 405. Fourth disconnect switch;

[0055] 501 DC disconnect switch; 601 First diode; 602 Second diode; 603 Diode circuit breaker; 701 Quench detector; 801 Programmable controller. Detailed Implementation

[0056] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0057] Please see Figure 1 - Figure 4 This utility model provides a technical solution:

[0058] A superconducting magnet structure for magnetically controlled Czochralski-grown single-crystal silicon includes:

[0059] The magnetically shielded vacuum cavity 105 has a vacuum-sealed environment inside.

[0060] A cold shield 104 is installed inside the magnetically shielded vacuum cavity 105;

[0061] A superconducting coil fixing cylinder 101 is set inside the cold screen 104;

[0062] And at least four superconducting coils 102 are fixed to the superconducting coil fixing cylinder 101 by the superconducting coil outer arc pressure plate 103;

[0063] Among them, the superconducting coil 102 is made of MgB2 superconducting material and is in the shape of a circular arc;

[0064] At least four superconducting coils 102 include a first coil 102A and a second coil 102B, as well as a third coil 102C and a fourth coil 102D, which are symmetrically distributed in pairs in mechanical position.

[0065] It also includes at least two refrigerators 107 located on top of the magnetically shielded vacuum chamber 105, which are used to cool the superconducting coil 102.

[0066] In this invention, the center angle between the first coil 102A and the third coil 102C is 108 degrees, and the center angle between the first coil 102A and the second coil 102B is 72 degrees.

[0067] In this invention, the refrigeration unit 107 includes a first refrigeration unit 107A and a second refrigeration unit 107B. The first refrigeration unit 107A and the second refrigeration unit 107B are respectively used to cool two adjacent superconducting coils 102. The first refrigeration unit 107A is used to cool the first coil 102A and the second coil 102B, and the second refrigeration unit 107B is used to cool the third coil 102C and the fourth coil 102D.

[0068] In this invention, a superconducting coil current lead 106 is also provided through the top of the magnetically shielded vacuum cavity 105. The superconducting coil current lead 106 includes a positive electrode 106A and a negative electrode 106B, which are electrically connected to the positive and negative terminals of the superconducting coil 102 circuit, respectively.

[0069] In this utility model, a cooling copper plate 109 is respectively provided between the first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D. The cooling copper plate 109 is connected to the superconducting coil outer arc pressure plate 103 on the first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D.

[0070] The inner arc surfaces of the first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D are all in contact with the superconducting coil fixing cylinder 101, and the inner arc surfaces of the first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D are all in contact with the superconducting coil outer arc pressure plate 103.

[0071] This invention also provides a protective device for a superconducting magnet structure used in magnetically controlled Czochralski single-crystal silicon, comprising:

[0072] The superconducting power supply 2 is electrically connected to the superconducting coil 102 via the superconducting coil current lead 106;

[0073] Programmable controller 801 connected to the superconducting power supply 2 via signal;

[0074] And an external protection resistor box electrically connected in the circuit of superconducting coil 102;

[0075] The external protection resistor box includes a diode assembly, multiple protection resistors connected in series, and a disconnect switch connected in parallel with the protection resistors;

[0076] The programmable controller 801 is configured to control the opening and closing of the disconnect switch to change the resistance value of the connected circuit.

[0077] In this utility model, the protection resistors include a first protection resistor 301, a second protection resistor 302, a third protection resistor 303, a fourth protection resistor 304, and a fifth protection resistor 305;

[0078] The disconnect switches include a first disconnect switch 402, a second disconnect switch 403, a third disconnect switch 404, a fourth disconnect switch 405, and a fifth disconnect switch 401;

[0079] The first protection resistor 301 is connected in series with the second protection resistor 302, the third protection resistor 303, the fourth protection resistor 304 and the fifth protection resistor 305 arranged in sequence;

[0080] The first disconnect switch 402 is connected in parallel across the second protective resistor 302;

[0081] The second disconnect switch 403 is connected in parallel across the third protective resistor 303;

[0082] The third disconnect switch 404 is connected in parallel across the fourth protective resistor 304;

[0083] The fourth disconnect switch 405 is connected in parallel across the fifth protective resistor 305;

[0084] The fifth disconnect switch 401 is connected in parallel across the series circuit of the second protective resistor 302, the third protective resistor 303, the fourth protective resistor 304 and the fifth protective resistor 305.

[0085] A diode assembly is connected in series at the end of the protective resistor away from the disconnect switch. The diode assembly includes a first diode 601 and a second diode 602 connected in parallel, and a diode circuit breaker 603 is connected in series in the circuit of the second diode 602.

[0086] The present invention also includes a quench detection circuit, which includes multiple voltage taps 108 connected to the superconducting coil 102 and a quench detector 701. The quench detector 701 is connected to the programmable controller 801 and the voltage taps 108 respectively.

[0087] In this invention, a DC cut-off switch 501 controlled by a programmable controller 801 is provided on the circuit between the superconducting power supply 2 and the superconducting coil 102.

[0088] When the quench detector 701 detects a quench signal, the programmable controller 801 is configured to perform the following operations:

[0089] The DC cut-off switch 501 is opened to cut off the power supply to the superconducting power supply 2;

[0090] Control the corresponding cut-off switch action to connect the external protection resistor box to the circuit of the superconducting coil 102, so that the stored energy is transferred to the external resistor for dissipation.

[0091] In this invention, the programmable controller 801 is configured to selectively close or open the corresponding cut-off switch when the quench detector 701 detects a quench signal based on the operating current value of the superconducting coil 102, so as to achieve graded control of the energy release rate.

[0092] Example: First, the superconducting coil fixing cylinder 101 is installed inside the cold shield 104, ensuring that the installation position is centered; then the entire cold shield 104 is placed into the magnetic shielding vacuum cavity 105, the magnetic shielding vacuum cavity 105 is sealed and a vacuum is drawn to form a vacuum sealing environment.

[0093] The first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D, all made of MgB2 superconducting material, are attached to the outer wall of the superconducting coil fixing cylinder 101. Their positions are adjusted to ensure that they are symmetrically distributed in pairs, according to the requirement that the center angle between the first coil 102A and the third coil 102C is 108 degrees and the center angle between the first coil 102A and the second coil 102B is 72 degrees.

[0094] The outer arc plate 103 of the superconducting coil covers the outer arc surfaces of the first coil 102A, the second coil 102B, the third coil 102C, and the fourth coil 102D. The outer arc plate 103 of the superconducting coil is fastened to the superconducting coil fixing cylinder 101 by bolts. Cooling copper plates 109 are installed between the first coil 102A and the second coil 102B, and between the third coil 102C and the fourth coil 102D, and are connected and fixed to the outer arc plate 103 of the superconducting coil.

[0095] A superconducting coil current lead 106 is installed on the top of the magnetically shielded vacuum cavity 105, and the positive electrode 106A and the negative electrode 106B are electrically connected to the positive and negative terminals of the total circuit composed of the first coil 102A, the second coil 102B, the third coil 102C and the fourth coil 102D, respectively. A first refrigerator 107A and a second refrigerator 107B are installed on the top of the magnetically shielded vacuum cavity 105, respectively aligned with the areas of the first coil 102A and the second coil 102B, and the third coil 102C and the fourth coil 102D, to ensure the cooling effect.

[0096] The superconducting power supply 2 is connected to the superconducting coil current lead 106 via a wire, and a DC cut-off switch 501 is connected in series in the circuit; the programmable controller 801 is connected to the superconducting power supply 2 to realize power supply status monitoring and control.

[0097] Assemble the external protection resistor box: Connect the first protection resistor 301, the second protection resistor 302, the third protection resistor 303, the fourth protection resistor 304, and the fifth protection resistor 305 in series. Connect the first disconnect switch 402 in parallel across the second protection resistor 302; connect the second disconnect switch 403 in parallel across the third protection resistor 303; connect the third disconnect switch 404 in parallel across the fourth protection resistor 304; connect the fourth disconnect switch 405 in parallel across the fifth protection resistor 305; connect the fifth disconnect switch 401 in parallel across the series circuit of the second protection resistor 302, the third protection resistor 303, the fourth protection resistor 304, and the fifth protection resistor 305. Connect a diode assembly in series at one end of the series circuit of the protection resistors. The diode assembly consists of the first diode 601 and the second diode 602 connected in parallel. Connect the second diode 602 in series with the diode circuit breaker 603. Then connect the entire external protection resistor box to the circuit of the superconducting coil 102.

[0098] Install the quench detection circuit: Connect multiple voltage taps 108 to different positions of the superconducting coil 102. The voltage taps 108 are connected to the quench detector 701, and the quench detector 701 is then connected to the programmable controller 801 to complete the construction of the detection and control link.

[0099] During normal operation: the superconducting power supply 2 supplies power to the superconducting coil 102, and the programmable controller 801 monitors the operating current of the superconducting coil 102; the first refrigerator 107A and the second refrigerator 107B continuously cool the superconducting coil 102 and maintain its temperature within the superconducting range of 10-20K through the cooling copper plate 109; the magnetically permeable outer wall of the magnetically shielded vacuum cavity 105 reduces external magnetic leakage and ensures magnetic field stability.

[0100] Overrun detection and protection: When the superconducting coil 102 quenches, the voltage tap 108 captures the abnormal voltage signal and transmits it to the overrun detector 701. The overrun detector 701 quickly judges and sends an overrun signal to the programmable controller 801. The programmable controller 801 immediately controls the DC cut-off switch 501 to open, cutting off the power supply to the superconducting power supply 2. At the same time, according to the current operating current of the superconducting coil 102, it controls the corresponding cut-off switch in the external protection resistor box to operate and connect a suitable combination of protection resistors.

[0101] Energy release and recovery: The connected protective resistor dissipates the electromagnetic energy stored in the superconducting coil 102 to prevent local overheating of the coil; after the energy is released, the refrigerator 107 continues to work to cool the superconducting coil 102 to the superconducting state, and then the power supply can be restarted to resume production.

[0102] For example, when the superconducting magnet inductance is 180H and the operating current is at its rated value, the programmable controller 801 controls the fifth cut-off switch 401 to close, connecting only the first protection resistor 301 with a resistance of 0.05 ohms. The current release time is approximately 3600 seconds, the temperature rise of the superconducting coil 102 is small, and it can quickly resume operation after cooling. When rapid energy dissipation is required, the fifth cut-off switch 401 is opened, and the third cut-off switch 404 and the fourth cut-off switch 405 are closed. The first protection resistor 301 and the second protection resistor 302, with a total resistance of 2 ohms, are connected, and the current release time is approximately 90 seconds. Although the temperature rise of the superconducting coil 102 is greater, it can still cool down and recover within a few hours.

[0103] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0104] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A superconducting magnet structure for a magnetic -controlled Czochralski single crystal silicon, characterized by comprising: The application relates to a superconducting magnetic shielding vacuum cavity, which comprises the following parts: a magnetic shielding vacuum cavity (105) with a vacuum sealed environment inside; a cold shield (104) arranged inside the magnetic shielding vacuum cavity (105); a superconducting coil fixing cylinder (101) arranged inside the cold shield (104); at least four superconducting coils (102) fixed on the superconducting coil fixing cylinder (101) through superconducting coil outer circular arc pressing plates (103); the superconducting coils (102) are in the shape of circular arcs; the at least four superconducting coils (102) comprise first coils (102A) and second coils (102B) and third coils (102C) and fourth coils (102D) which are symmetrically distributed in mechanical positions; at least two refrigerators (107) arranged on the top of the magnetic shielding vacuum cavity (105) are further included, and the refrigerators (107) are used for cooling the superconducting coils (102); the refrigerators (107) comprise a first refrigerator (107A) and a second refrigerator (107B), the first refrigerator (107A) and the second refrigerator (107B) are respectively used for cooling two adjacent superconducting coils (102), wherein the first refrigerator (107A) is used for cooling the first coils (102A) and the second coils (102B), and the second refrigerator (107B) is used for cooling the third coils (102C) and the fourth coils (102D).

2. A superconducting magnet structure for a magnetic -controlled -dopant Czochralski silicon crystal growth system as defined in claim 1, wherein: The central angle between the first coils (102A) and the third coils (102C) is 108 degrees, and the central angle between the first coils (102A) and the second coils (102B) is 72 degrees.

3. A superconducting magnet structure for a magnetic -cutfing single crystal silicon puller as defined in claim 1, wherein: A superconducting coil current lead (106) is further arranged on the top of the magnetic shielding vacuum cavity (105), the superconducting coil current lead (106) comprises a positive electrode (106A) and a negative electrode (106B), and the positive electrode (106A) and the negative electrode (106B) are electrically connected with the positive electrode and the negative electrode of the total circuit of the superconducting coils (102) respectively.

4. A superconducting magnet structure for a magnetic -cutfing single crystal silicon puller as defined in claim 1, wherein: A cold copper plate (109) is arranged between the first coils (102A) and the second coils (102B) and the third coils (102C) and the fourth coils (102D) respectively, and the cold copper plate (109) is connected with the superconducting coil outer circular arc pressing plates (103) on the first coils (102A) and the second coils (102B) and the third coils (102C) and the fourth coils (102D). The inner circular arc surfaces of the first coils (102A), the second coils (102B), the third coils (102C) and the fourth coils (102D) are attached to the superconducting coil fixing cylinder (101), and the inner circular arc surfaces of the first coils (102A), the second coils (102B), the third coils (102C) and the fourth coils (102D) are attached to the superconducting coil outer circular arc pressing plates (103).

5. A protection device for a superconducting magnet structure for a magnetic- control Czochralski single crystal silicon as claimed in any one of claims 1 to 4, characterized in that The application further relates to a superconducting magnetic shielding vacuum cavity control system, which comprises the following parts: a superconducting power supply (2) electrically connected to the superconducting coils (102) through the superconducting coil current lead (106); a programmable controller (801) signal connected with the superconducting power supply (2); and an external protection resistor box electrically connected in the loop of the superconducting coils (102). The external protection resistor box comprises a diode assembly, a plurality of series-connected protection resistors, and a cut-off switch connected in parallel with the protection resistors. The programmable controller (801) is configured to control the opening of the cut-off switch to change the resistance value of the access loop.

6. The protection device for superconducting magnet structures for magnetic- control Czochralski single crystal silicon according to claim 5, characterized in that The protection resistors comprise a first protection resistor (301), a second protection resistor (302), a third protection resistor (303), a fourth protection resistor (304), and a fifth protection resistor (305). The cut-off switches comprise a first cut-off switch (402), a second cut-off switch (403), a third cut-off switch (404), a fourth cut-off switch (405), and a fifth cut-off switch (401). The first protection resistor (301) is connected in series with the second protection resistor (302), the third protection resistor (303), the fourth protection resistor (304), and the fifth protection resistor (305) arranged in sequence. The first cut-off switch (402) is connected in parallel across the second protection resistor (302). The second cut-off switch (403) is connected in parallel across the third protection resistor (303). The third cut-off switch (404) is connected in parallel across the fourth protection resistor (304). The fourth cut-off switch (405) is connected in parallel across the fifth protection resistor (305). The fifth cut-off switch (401) is connected in parallel across the series circuit of the second protection resistor (302), the third protection resistor (303), the fourth protection resistor (304), and the fifth protection resistor (305). The end of the protection resistor away from the cut-off switch is further connected in series with a diode assembly, the diode assembly comprising a first diode (601) and a second diode (602) connected in parallel with each other, and a diode loop breaker (603) connected in series with the loop of the second diode (602).

7. The magnetic control Czochralski silicon single crystal pulling superconducting magnet structure protection apparatus according to claim 5, characterized by, Further comprising a quench detection circuit, the quench detection circuit comprising a plurality of voltage taps (108) connected to the superconducting coil (102) and a quench detector (701), the quench detector (701) being signal-connected to the programmable controller (801) and the voltage taps (108) respectively.

8. The protection device for superconducting magnet structures for magnetic- control Czochralski single crystal silicon according to claim 7, characterized in that The superconducting power supply (2) is provided with a direct-current cut-off switch (501) controlled by the programmable controller (801) in the loop of the superconducting coil (102). When the quench detector (701) detects a quench signal, the programmable controller (801) is configured to perform the following operations: Control the direct-current cut-off switch (501) to be opened to cut off the power supply of the superconducting power supply (2); Control the corresponding cut-off switch to act to connect the external protection resistor box to the loop of the superconducting coil (102) to transfer the energy storage to the external resistance dissipation.

9. The protection device for superconducting magnet structures for magnetic- control Czochralski single crystal silicon according to claim 8, characterized in that The programmable controller (801) is configured to selectively close or open the corresponding cut-off switch according to the working current value of the superconducting coil (102) when the quench detector (701) detects a quench signal, to realize the hierarchical control of the energy release speed.

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