CRYOGENIC DEVICE

Abstract

A cryogenic device (10) comprises a vacuum chamber (12), a superconducting coil (14) arranged in the vacuum chamber (12), a cryocooler (20) installed in the vacuum chamber (12) to cool the superconducting coil (14), a power introduction terminal (30) installed in the vacuum chamber (12) and connected to the superconducting coil (14), and a condensate water tank (44) provided around an exposed portion exposed from the vacuum chamber (12) of at least one of the cryocooler (20) and the power introduction terminal (30) below the exposed portion.

Description

Technical area

[0001] The present invention relates to a cryogenic device.

[0002] This application claims priority from Japanese Patent Application No. 2022-172327, filed on October 27, 2022. The entire contents of the application are incorporated herein by reference. State of the art

[0003] A cryogenic device is known in the art that includes a cryocooler and a vacuum chamber. For example, various objects to be cooled, such as superconducting devices such as a superconducting coil, other devices used in a cryogenic environment, and a cryogenic refrigerant for cooling such devices, are housed in the vacuum chamber. The cryocooler is used to cool the objects to be cooled. Citation listPatent literature

[0004] [PTL 1] Japanese Unexamined Patent Publication No. 2019-200003 Summary of the inventionTechnical problem

[0005] In a case where maintenance of the cryogenic device is performed, the energization of the superconducting coil may be stopped, or a cooling operation to be performed by the cryocooler may be stopped. In this case, a thermal equilibrium in the cryogenic device changes from that during normal operation of the cryogenic device, and the superconducting coil, which has been cryogenically cooled in the vacuum chamber, serves as a cooling source, so that a component of the cryogenic device that is connected to the superconducting coil in a heat-transfer manner can be cooled.In this way, for example, portions exposed to the surrounding environment on an outer surface of the vacuum chamber, such as a power introduction terminal for supplying current to the superconducting coil and a drive unit of the cryocooler, are cooled, and condensation or freezing of moisture in the ambient air may occur on the exposed portions. For this reason, there is a concern that condensate water on the cryogenic device will spread to the surrounding environment and cause adverse effects. For example, an iron material, such as a magnetic shield or a yoke surrounding the vacuum chamber, may be wet, which can cause rust. Alternatively, the adhesion of water droplets to an excitation unit, such as the power introduction terminal, may lead to a risk of malfunction in an electrical system, such as electrical leakage.

[0006] One of exemplary objects of an aspect of the present invention is to deal with condensation that may occur in a cryogenic device. Solution to the problem

[0007] According to one aspect of the present invention, there is provided a cryogenic device comprising: a vacuum chamber; a superconducting coil disposed in the vacuum chamber; a cryocooler installed in the vacuum chamber to cool the superconducting coil; a power introduction terminal installed in the vacuum chamber and connected to the superconducting coil; and a condensate water tank provided around an exposed portion, exposed from the vacuum chamber, of at least one of the cryocooler and the power introduction terminal below the exposed portion. Advantageous effects of the invention

[0008] According to the present invention, it is possible to deal with condensation that may occur in the cryogenic device. Brief description of the drawings Fig. 1 is a diagram schematically showing a cryogenic device according to an embodiment. Fig. 2 is a diagram schematically showing a condensate water tank according to a modification example. Fig. 3 is a diagram schematically showing a cryogenic device according to another embodiment. Description of embodiments

[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, elements, and processing in the specification and the drawings are denoted by the same reference numerals, and repeated description thereof is appropriately omitted. The scale and shape of each part to be shown in the drawings are conveniently set for convenience of description and, unless otherwise specified, are not interpreted in a limited manner. The embodiments are exemplary and do not limit the scope of the present invention in any way. All features to be described in the embodiments and combinations thereof are not necessarily essential to the present invention.

[0010] Fig. 1 is a diagram schematically showing a cryogenic device 10 according to an embodiment. An internal structure of the cryogenic device 10 is shown in Fig. 1. The cryogenic device 10 is a superconducting magnet device and includes a vacuum chamber 12, a superconducting coil 14 disposed within the vacuum chamber 12, a cryocooler 20 installed within the vacuum chamber 12 to cool the superconducting coil 14, and a current introduction terminal 30 installed within the vacuum chamber 12 and connected to the superconducting coil 14. The superconducting magnet device can be used, for example, as a magnetic field source for a single-crystal pulling device.

[0011] The vacuum chamber 12 is a thermally insulated vacuum chamber that provides a cryogenic vacuum environment suitable for bringing the superconducting coil 14 into a superconducting state, and is also referred to as a cryostat. Typically, the vacuum chamber 12 has a columnar shape or a cylindrical shape with a hollow portion at a central portion. Accordingly, the vacuum chamber 12 includes a top plate 12a and a bottom plate 12b having a substantially flat circular or annular shape, and a cylindrical side wall (a cylindrical outer peripheral wall or a cylindrical outer peripheral wall and a cylindrical inner peripheral wall arranged coaxially) connecting the top plate 12a and the bottom plate 12b.The vacuum chamber 12 is made of, for example, a metal material such as stainless steel or other suitable high-strength material to withstand ambient pressure (for example, atmospheric pressure).

[0012] The superconducting coil 14 is connected to an external power source 16 via the current introduction port 30. The current introduction port 30 corresponds to a tip of a current path to the superconducting coil 14 provided in the vacuum chamber 12, and the current path is also often referred to as a current line. The current introduction port 30 is a hermetic port provided on a wall surface of the vacuum chamber 12 and introduces a current from the outside of the vacuum chamber 12 to the inside of the vacuum chamber 12 while maintaining airtightness within the vacuum chamber 12. Although in Fig. While only one current introduction terminal 30 is shown in FIG. 1 for simplicity, generally, at least one pair of current introduction terminals 30 (and at least one pair of power lines) are provided on a positive electrode side and a negative electrode side. The current introduction terminal 30 is provided at the bottom plate 12b of the vacuum chamber 12 in this example. An exciting current is supplied from the external power source 18 to the superconducting coil 14 via the current introduction terminal 30 in a state where the superconducting coil 14 is cooled by the cryocooler 20 to a cryogenic temperature equal to or lower than a superconducting transition temperature. Accordingly, the superconducting coil 14 can generate a strong magnetic field.

[0013] The cryocooler 20 includes a compressor (not shown) for refrigerant gas (e.g., helium gas) and an expander, also referred to as a cold head. A refrigeration cycle of the cryocooler 20 is formed by the compressor and expander, thus providing cryogenic refrigeration. The cryocooler 20 is, for example, a two-stage Gifford-McMahon (GM) cryocooler. The cryocooler 20 includes a first cooling stage 22a and a second cooling stage 22b as a low-temperature section to be cooled to a cryogenic temperature. These cooling stages are arranged in the vacuum chamber 12. The first cooling stage 22a and the second cooling stage 22b are made of, for example, a metal material such as copper or other materials with high thermal conductivity.

[0014] The cryocooler 20 further includes a first cylinder 24a, a second cylinder 24b, a cold head drive unit 26, and a mounting flange 28. The first cylinder 24a connects the mounting flange 28 to the first cooling stage 22a, and the second cylinder 24b connects the first cooling stage 22a to the second cooling stage 22b. The cold head drive unit 26 is provided on a side opposite the first cylinder 24a and is attached to the mounting flange 28.

[0015] For example, the first cylinder 24a and the second cylinder 24b are members having a cylindrical shape, and a diameter of the second cylinder 24b is smaller than a diameter of the first cylinder 24a. The first cylinder 24a and the second cylinder 24b are arranged coaxially, and a lower end of the first cylinder 24a is rigidly connected to an upper end of the second cylinder 24b. In a case where the cryocooler 20 is a GM cryocooler, a first displacer and a second displacer in which a replenisher material is incorporated are respectively housed in the first cylinder 24a and the second cylinder 24b. The first displacer and the second displacer are connected to each other and can reciprocate respectively along the first cylinder 24a and the second cylinder 24b.The first cylinder 24a and the second cylinder 24b are typically made of, for example, a metal material having a lower thermal conductivity than the first cooling stage 22a and the second cooling stage 22b, such as stainless steel.

[0016] The cold head drive unit 26 includes a motor and a connecting mechanism that connects the motor to the first displacer and the second displacer, converting rotational motion output from the motor into reciprocating motions of the first displacer and the second displacer. Furthermore, the cold head drive unit 26 includes a pressure switching valve that periodically switches the internal pressures of the first cylinder 24a and the second cylinder 24b to high pressure and low pressure, respectively. The pressure switching valve is also driven by the same motor.

[0017] In this example, a cold head of the cryocooler 20 is installed on the cover plate 12a of the vacuum chamber 12. The cover plate 12a of the vacuum chamber 12 is provided with an opening portion 32 through which the cold head is inserted into the vacuum chamber 12. The cold head is installed vertically in the vacuum chamber 12 with the cold head drive unit 26 facing upward and the first cooling stage 22a and the second cooling stage 22b facing downward. The cold head drive unit 26 is exposed to an ambient environment (for example, an environment below room temperature and atmospheric pressure) of the vacuum chamber 12.

[0018] During operation of the cryocooler 20, the first cooling stage 22a is cooled to a first cooling temperature, for example, a temperature in a range of 30 K to 80 K, and the second cooling stage 22b is cooled to a second cooling temperature lower than the first cooling temperature, for example, a temperature in a range of 3 K to 20 K.

[0019] A radiant heat shield 34 is arranged in the vacuum chamber 12 along with the low-temperature section of the cryocooler 20 and the superconducting coil 14. The radiant heat shield 34 is thermally coupled to the first cooling stage 22a and is cooled to the first cooling temperature. The radiant heat shield 34 is directly attached to the first cooling stage 22a and is thermally coupled to the first cooling stage 22a. Alternatively, the radiant heat shield 34 can be attached to the first cooling stage 22a via a heat transfer element with flexibility or rigidity. The radiant heat shield 34 is made, for example, of a metal material such as copper or other materials with high thermal conductivity.The radiant heat shield 34 is arranged to surround the superconducting coil 14, the second cooling stage 22b of the cryocooler 20, and other low-temperature sections to be cooled to the second cooling temperature, and can thermally protect these low-temperature sections from external radiant heat.

[0020] The superconducting coil 14 is thermally coupled to the second cooling stage 22b via a heat transfer element 36 and is cooled to the second cooling temperature. The heat transfer element 36 can be a heat transfer element with flexibility or rigidity and is made, for example, of a metal material such as copper or other materials with high thermal conductivity. Alternatively, the superconducting coil 14 can be attached directly to the second cooling stage 22b.

[0021] The vacuum chamber 12 may include a magnetic shield 38 on the outside thereof to suppress the leakage of a magnetic field generated by the superconducting coil 14 to the outside. The magnetic shield 38 covers the top plate 12a and the bottom plate 12b of the vacuum chamber 12 and a side wall connecting the top plate 12a and the bottom plate 12b. The magnetic shield 38 is made of a magnetic material such as iron. An opening portion receiving the cold head drive unit 26 of the cryocooler 20 is formed on a top plate 38a of the magnetic shield 38 adjacent to the top plate 12a of the vacuum chamber 12, and the cold head drive unit 26 is arranged to protrude upward from the magnetic shield 38, as shown in FIG. Fig. 1 shown.

[0022] In this embodiment, the vacuum chamber 12 includes a first tubular portion 40 extending downward into the vacuum chamber 12 from the opening portion 32 of the cover plate 12a, and a second tubular portion 42 extending downward into the first tubular portion 40 from an exposed portion (i.e., the cold head drive unit 26) exposed from the vacuum chamber 12 of the cryocooler 20. A double tube formed from the first tubular portion 40 and the second tubular portion 42 connects the cover plate 12a of the vacuum chamber 12 to the cold head drive unit 26 at the opening portion 32 while maintaining airtightness within the vacuum chamber 12.

[0023] The first tubular portion 40 is, for example, in the shape of a hollow tube, such as a cylinder, and is made of a metal material, such as stainless steel, or other suitable materials. The first tubular portion 40 may include an inner flange at a lower end thereof, to which the second tubular portion 42 is to be attached.

[0024] The second tubular section 42 connects the cold head drive unit 26 (more particularly the mounting flange 28) to the first tubular section 40. The second tubular section 42 may be deformable and may, for example, be a bellows. Alternatively, the second tubular section 42 may be made of a metal material, such as stainless steel, like the first tubular section 40, and may rigidly connect the cold head drive unit 26 and the first tubular section 40.

[0025] The first tubular portion 40 may be deformable instead of (or together with) the second tubular portion 42 and may, for example, be a bellows. In a case where at least one of the first tubular portion 40 and the second tubular portion 42 is made deformable, the thermal shrinkage of the low-temperature portion that may occur during cryogenic cooling can be absorbed.

[0026] As described above, in a case where maintenance of the cryogenic device 10 is performed, a thermal equilibrium in the cryogenic device 10 may change from that during normal operation of the cryogenic device 10 due to the cessation of the energization of the superconducting coil 14 or the cessation of the cooling performed by the cryocooler 20. Accordingly, the superconducting coil 14, which has been cryogenically cooled in the vacuum chamber 12, serves as a cooling source, so that a component of the cryogenic device 10 that is connected to the superconducting coil 14 in a heat-transfer manner, for example, the cold head drive unit 26 of the cryocooler 20, can be cooled. For this reason, moisture in the ambient air may condense on the cold head drive unit 26 during maintenance work of the cryogenic device 10.In a case where condensate water spreads to the surroundings, the condensate water may adhere to the magnetic shield 38. Since the magnetic shield 38 is made of an iron material, the adhering water may cause rust.

[0027] As in Fig. 1, an annular (e.g., circular) recess is formed between the first tubular portion 40 and the second tubular portion 42 under the cover plate 12a of the vacuum chamber 12. Since this recess is provided around the cold head drive unit 26, the recess can function as a condensate water tank 44 that receives the condensate water. That is, water droplets condensed on the cold head drive unit 26 flow down to the condensate water tank 44 and are collected in the condensate water tank 44. The condensate water stored in the condensate water tank 44 can be removed as needed (e.g., during maintenance or at the end of maintenance) by wiping or the like, or it can be left to evaporate naturally.In this way, it is possible to reduce or prevent the spread of condensate water to the surrounding environment. Since the condensate water reservoir 44 is provided on a side of the cover plate 12a of the vacuum chamber 12 opposite the upper plate 38a of the magnetic shield 38 (i.e., on a lower side of the cover plate 12a), the occurrence of rust on the magnetic shield 38 caused by contact with the condensate water is also reduced or prevented.

[0028] Fig. 2 is a diagram schematically showing a condensate water tank 44 according to a modification example. In the embodiment described with reference to Fig. In the cryogenic device 10 described in FIG. 1, the power introduction port 30 is provided in the bottom plate 12b of the vacuum chamber 12. However, the cryogenic device 10 can also be designed to use the power introduction port 30 provided in the top plate 12a of the vacuum chamber 12. Since condensation may also occur at the power introduction port 30 as in the cold head drive unit 26 described above, the condensate water tank 44 according to the embodiment can be applied to the power introduction port 30.

[0029] As in Fig. 2, a vacuum chamber 12 includes a first tubular portion 40 extending downward into the vacuum chamber 12 from an opening portion 32 of a ceiling plate 12a, and a second tubular portion 42 extending downward into the first tubular portion 40 from an exposed portion of the vacuum chamber 12, in this case, the power introduction port 30. A double tube formed from the first tubular portion 40 and the second tubular portion 42 connects the ceiling plate 12a of the vacuum chamber 12 to the power introduction port 30 at the opening portion 32 while maintaining airtightness within the vacuum chamber 12. The second tubular portion 42 may be a tubular housing that houses a power conductor 31 connected to the power introduction port 30.At least one of the first tubular portion 40 and the second tubular portion 42 may, for example, include a bellows and may be deformable.

[0030] An annular recess serving as the condensate water tank 44 is formed between the first tubular portion 40 and the second tubular portion 42 under the cover plate 12a of the vacuum chamber 12. The condensate water tank 44 is provided around the power introduction port 30 below the power introduction port 30. Lower ends of the first tubular portion 40 and the second tubular portion 42 are connected to each other by a bottom plate 46 of the condensate water tank 44. The bottom plate 46 may be an inner flange of the first tubular portion 40 as described above, may be an outer flange of the second tubular portion 42, or may be a member separate from the first tubular portion 40 and the second tubular portion 42.

[0031] As shown by arrows 48, water droplets adhering to the power supply terminal 30 due to condensation flow down to the condensate tank 44 and are collected in the condensate tank 44. In this way, it is possible to reduce or prevent the spread of the condensate to the surroundings. Since the condensate tank 44 is provided on a side of the cover plate 12a of the vacuum chamber 12 opposite the upper plate 38a of the magnetic shield 38, the occurrence of rust on the magnetic shield 38 caused by contact with the condensate is also reduced or prevented. Furthermore, the risk of malfunction in an electrical system, such as electrical leakage, can also be reduced.

[0032] Fig.Figure 3 is a diagram schematically showing a cryogenic device 10 according to another embodiment. The cryogenic device 10 is a superconducting magnet device and includes a vacuum chamber 12, a superconducting coil 14 disposed in the vacuum chamber 12, a cryocooler 20 installed in the vacuum chamber 12 to cool the superconducting coil 14, and a current introduction terminal 30 installed in the vacuum chamber 12 and connected to the superconducting coil 14. The superconducting magnet device can be used, for example, as a magnetic field source for a cyclotron.

[0033] The vacuum chamber 12 includes a vacuum chamber body 50 that houses the superconducting coil 14, a first tubular portion 52 that houses a power line 31, and a second tubular portion 54 that houses the cryocooler 20. The vacuum chamber body 50 includes a top plate 12a, a bottom plate 12b, and a side wall connecting the top plate 12a and the bottom plate 12b. The first tubular portion 52 protrudes upward from the top plate 12a of the vacuum chamber body 50 and extends to an exposed portion of the power line 31 exposed from the vacuum chamber 12, that is, to the power introduction port 30. In other words, the power introduction port 30 is exposed to a surrounding area of ​​the vacuum chamber 12 at an upper end of the first tubular portion 52.The second tubular portion 54 protrudes upward from the cover plate 12a of the vacuum chamber body 50 and extends to an exposed portion of the cryocooler 20 exposed from the vacuum chamber 12, that is, to a cold head drive unit 26. The cold head drive unit 26 is exposed to a surroundings around the vacuum chamber 12 at an upper end of the second tubular portion 54.

[0034] The cryogenic device 10 further includes a yoke 56 surrounding the vacuum chamber 12. The yoke 56 is made of a magnetic material, such as iron. In this example, the yoke 56 has a split structure and includes an upper yoke 56a surrounding an upper portion of the vacuum chamber 12 and a lower yoke 56b surrounding a lower portion of the vacuum chamber 12. A first opening portion is formed in the upper yoke 56a, which receives the first tubular portion 52 of the vacuum chamber 12, and a gap 58 is formed between the upper yoke 56a and the first tubular portion 52 in this opening portion. Similarly, in the upper yoke 56a, a second opening portion receiving the second tubular portion 54 of the vacuum chamber 12 is formed, and a gap 60 is formed between the upper yoke 56a and the second tubular portion 54 in this opening portion.The upper yoke 56a has a yoke cover surface 56a1 surrounding the first tubular portion 52 and the second tubular portion 54.

[0035] The upper yoke 56a can be moved up and down relative to the vacuum chamber 12. For example, in a case where maintenance of the cryogenic device 10 is being performed, the upper yoke 56a can be separated from the lower yoke 56b and moved upward. Accordingly, a work space through which a worker can access the vacuum chamber 12 can be formed between the upper yoke 56a and the lower yoke 56b. When maintenance is completed, the upper yoke 56a can be moved down, the work space can be closed, and the upper yoke 56a can be recoupled to the lower yoke 56b.

[0036] In this embodiment, a condensate tank 44 includes two condensate pans 44a and two condensate guides 44b on the yoke cover surface 56a1. The condensate pans 44a and the condensate guides 44b are provided to correspond to the first tubular portion 52 and the second tubular portion 54, respectively.

[0037] With respect to the first tubular portion 52, the condensate pan 44a is provided around the power introduction port 30 below the power introduction port 30. Further, the condensate guide 44b is disposed above the gap 58 between the first tubular portion 52 and the upper yoke 56a so as to cover the gap 58 and is adapted to guide the condensate flowing downward from the power introduction port 30 to the condensate pan 44a. The condensate guide 44b has an annular shape, an inner peripheral edge of the condensate guide 44b is attached to an upper end of the first tubular portion 52 and is provided over the entire circumference of the first tubular portion 52, and an outer peripheral edge of the condensate guide 44b is positioned above or within the condensate pan 44a.Therefore, water droplets adhering to the power introduction port 30 due to condensation flow on an upper surface of the condensate water guide 44b and are collected in the condensate water pan 44a.

[0038] Similarly, with respect to the second tubular portion 54, the condensate pan 44a is provided around the cold head drive unit 26 below the cold head drive unit 26. Furthermore, the condensate guide 44b is disposed above the gap 60 between the second tubular portion 54 and the upper yoke 56a so as to cover the gap 60 and is adapted to guide the condensate flowing downward from the cold head drive unit 26 to the condensate pan 44a. The condensate guide 44b has an annular shape, an inner peripheral edge of the condensate guide 44b is attached to an upper end of the second tubular portion 54 and is provided over the entire circumference of the second tubular portion 54, and an outer peripheral edge of the condensate guide 44b is positioned above or within the condensate pan 44a.Therefore, water droplets adhering to the cold head drive unit 26 due to condensation flow on an upper surface of the condensate water guide 44b and are collected in the condensate water pan 44a.

[0039] Accordingly, the condensate tank 44 can reduce or prevent the spread of condensate to the surrounding environment. The occurrence of rust on the yoke 56 caused by contact with the condensate is also reduced or prevented. Furthermore, the risk of malfunctions in an electrical system, such as electrical leakage, can also be reduced.

[0040] The condensate guide 44b may be flexible. For example, the condensate guide 44b may be made of a suitable synthetic resin material, such as a silicone resin or a fluorine-based resin, in a sheet shape and may be deformable. Accordingly, in a case where the upper yoke 56a with the condensate pan 44a is moved relative to the first tubular portion 52 and the second tubular portion 54, the condensate guide 44b is deformable and thus does not hinder the movement of the upper yoke 56a and the condensate pan 44a, which is advantageous.

[0041] The present invention has been described above based on the examples. It will be understood by those skilled in the art that the present invention may have various design changes and various modification examples without being limited to the above-mentioned embodiments, and the modification examples are also included within the scope of the present invention. Various features described with respect to a specific embodiment can also be applied to other embodiments. A new embodiment formed from the combination of embodiments has the effects of the respective combined embodiments.

[0042] A case where the cryogenic device 10 is configured as a so-called conduction-cooling type cryogenic device that directly cools the superconducting coil 14 with the cryocooler 20 has been exemplified in the above-described embodiments. However, in a specific embodiment, the cryogenic device 10 may be an immersion-cooling type cryogenic device in which the superconducting coil 14 is immersed in a cryogenic liquid refrigerant, such as liquid helium. In this case, the cryocooler 20 recondenses the evaporated cryogenic liquid refrigerant to cool the superconducting coil 14.

[0043] A case in which the cryocooler 20 is a two-stage GM cryocooler has been described by way of example in the embodiments described above. However, the cryocooler 20 may be a single-stage GM cryocooler in a particular embodiment. Alternatively, the cryocooler 20 may be a pulse tube cryocooler, a Stirling cryocooler, or other types of cryocoolers, such as a single-stage or multi-stage cryocooler.

[0044] Although the present invention has been described using specific words and expressions based on the embodiment, the embodiment merely represents one aspect of the principle and application of the present invention. Many modification examples and changes in arrangement are permissible in the embodiment without departing from the scope of the present invention defined in claims. Industrial applicability

[0045] The present invention can be used in the field of cryogenic devices. List of reference symbols 10 Cryogenic device 12 Vacuum chamber 12a cover plate 14 superconducting coil 20 cryocoolers 30 Power entry connection 32 opening section 40 first tubular section 42 second tubular section 44 Condensate water tank 44a Condensate tray 44b Condensate water drainage 50 vacuum chamber bodies 56 yoke 56a1 yoke cover surface 58, 60 gap QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2022-172327

[0002] JP 2019-200003

[0004]

Claims

[1] Cryogenic device comprising: a vacuum chamber; a superconducting coil arranged in the vacuum chamber; a cryocooler installed in the vacuum chamber to cool the superconducting coil; a current introduction terminal installed in the vacuum chamber and connected to the superconducting coil; and a condensate water tank provided around an exposed portion exposed from the vacuum chamber of at least one of the cryocooler and the power introduction port below the exposed portion. [2] Cryogenic device according to claim 1, wherein the vacuum chamber contains: a vacuum chamber cover plate containing an opening section, a first tubular portion extending downwardly from the opening portion of the vacuum chamber cover plate into the vacuum chamber, and a second tubular portion extending downwardly from the exposed portion into the first tubular portion, and the condensate water tank is provided between the first tubular section and the second tubular section. [3] Cryogenic device according to claim 2, further comprising: a magnetic shield including an upper plate of magnetic shield provided outside the vacuum chamber and adjacent to the vacuum chamber cover plate, wherein the condensate water tank is provided between the first tubular portion and the second tubular portion on a side of the vacuum chamber cover plate opposite to the upper plate of magnetic shielding. [4] A cryogenic device according to claim 2 or 3, wherein at least one of the first tubular portion and the second tubular portion is deformable. [5] Cryogenic device according to claim 1, wherein the vacuum chamber includes a vacuum chamber body accommodating the superconducting coil, and a tubular portion projecting upward from the vacuum chamber body and extending to the exposed portion, the cryogenic device further includes a yoke having a yoke cover surface surrounding the tubular portion, and the condensate water tank is provided on the yoke cover surface. [6] Cryogenic device according to claim 5, further comprising: a condensate water guide disposed over a gap between the tubular portion and the yoke to cover the gap, and adapted to guide condensate water flowing downward from the exposed portion to the condensate water tank. [7] Cryogenic device according to claim 6, wherein the condensate water guide has flexibility.

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