JP2744672B2 - Superconducting magnet device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device using a combination of superconducting magnets, and more particularly to a superconducting magnet device in a case where there is an interaction of electromagnetic force between the superconducting magnets.

[Prior Art] FIG. 3 is an overall plan view of an electron storage ring using a conventional superconducting magnet device disclosed in, for example, JP-A-64-2300. In the figure, a superconducting deflection magnet (1) comprises an iron core (2) and a superconducting coil (3). The quadrupole electromagnet (4) and the high-frequency accelerating cavity (5) are arranged along the equilibrium orbit (7) of the electron beam orbiting through the vacuum chamber (6). (8) is an inflector.

With the above configuration, the electron storage ring is a device for storing high-speed electrons accelerated by a linear accelerator, an electron synchrotron, or the like for a long time. Charged particles incident from the inflector (8) rotate inside the race-track-shaped chamber (6) at high speed. The deflection magnet (1) functions to bend the electrons. However, if the deflection magnet (1) alone is used, the electrons spread and move away from the deflection orbit (7), and immediately collide with the inner wall of the vacuum chamber (6) and disappear. Therefore, a quadrupole electromagnet (4) that functions to focus electrons on an equilibrium orbit is required. The high-frequency accelerating cavity (5) is a device for compensating for a decrease in the kinetic energy of electrons circulating in the storage ring, and the inflector (8) is a device for introducing electrons into the storage ring.

As described above, by arranging the components on the balanced orbit (7), the basic type of the conventional superconducting small SOR device is established. As other components described above, various measuring devices and vacuum pumps are required, and depending on the design method of the electron storage ring, a six-pole electromagnet having a function of correcting electron aberration is required. The description is omitted because it is far from the content of the invention.

Since the iron core (2) and the superconducting coil (3) constituting the superconducting deflection magnet (1) are located at a close distance, the superconducting coil (3) is excited and an intense electromagnetic force acts. I am strongly drawn to (2). Since the superconducting coil (3) is usually symmetrical with respect to the vertical direction of the iron core (2), the electromagnetic force acting on the superconducting coil (3) and the iron core (2) and the superconducting coil (3) and the iron core (2) 2) The electromagnetic force acting on the lower part is balanced. However, since the core of the side portion is mainly present on the outer peripheral side of the electron storage ring, the magnetic flux generated by the excitation of the superconducting coil (3) is
Most of it passes through the outer periphery of the electron storage ring, and as a result, a strong horizontal electromagnetic force acts on the superconducting coil (3) on the outer periphery of the electron storage ring. In order to support these electromagnetic forces, an electromagnetic force supporting member is attached to the superconducting magnet (1) so as to penetrate from a normal temperature region to a very low temperature region. When the electromagnetic force is large, the support member becomes thick, and as a result, the amount of heat that enters the cryogenic region by heat conduction increases significantly. The superconducting coil (3)
Although it is immersed in liquid helium with a boiling point temperature of 4.2K at atmospheric pressure, the evaporation of liquid helium is remarkable if the amount of heat entering the cryogenic region is large.

[Problems to be Solved by the Invention] Since the conventional superconducting magnet device is configured as described above, it consumes a large amount of expensive liquid helium,
Further, the lining cost of the apparatus has been extremely increased, for example, the number of injections of liquid helium has been increased. Further, there is another problem that liquid helium must be filled in each superconducting magnet.

As a method of operating the superconducting magnet, a helium refrigerator may be installed instead of a liquid helium reservoir. In this case, if the heat penetration amount is large, there is a problem that a large-capacity refrigerator is required, or a refrigerator must be independently attached to each superconducting magnet.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a superconducting magnet device in which heat penetration due to conduction from an electromagnetic force supporting material is small and a lining cost is extremely low.

[Means for Solving the Problems] In a superconducting magnet device according to the present invention, a plurality of superconducting magnets are connected in a cryogenic region.

[Operation] In the present invention, there is no need to attach a strong electromagnetic force supporting member between the normal temperature portion and the low temperature portion, and only the connection between the cryogenic regions is sufficient. Heat intrusion into the cryogenic part is eliminated.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention, wherein (23) is a room temperature space, (24) is a vacuum vessel, (25) is a vacuum region, and (26) is nitrogen. A shield, (27) is a helium container, (28) is a coil bobbin, and (29) is a connecting rod. In addition, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts.

As shown in the figure, sandwich the room temperature space (23)
A vacuum vessel (25) is provided inside the room temperature space (23), and a magnetic shield iron core (2) is provided outside the room.
Various components for operating the superconducting coil (3) are included inside the vacuum vessel (24). The vacuum vessel (24) itself has a vacuum insulation function with the room temperature space (23), and the inner layer of the vacuum vessel (24) is a vacuum area (25).

With the above configuration, the inside of the vacuum region (25) is the nitrogen shield (26), and the nitrogen shield (26) is cooled to a temperature of about 80K by heat exchange with liquid nitrogen. This nitrogen shield (26) is effective against heat intrusion from the outside, particularly, heat intrusion by radiation.

Inside the nitrogen shield (26) is a helium container (27), which is kept at a very low temperature near the boiling point of helium (4.2K, 1 atm) by liquid helium. The helium container (27) has a superconducting coil (3) and a coil bobbin (28) for fixing the superconducting coil (3). It is firmly fixed to the reel. In addition, reel (28) and connecting rod (29)
Are connected in a cryogenic region. In this embodiment, 1
Two coil winding frames (28) are housed in one helium container (27), and are connected to the winding frames by connecting rods (29) at the same temperature level. A heat insulating structure required for a normal magnet is provided around the connecting rod (29). In addition, a supporting structure for supporting the helium container (27) by its own weight and supporting a non-equilibrium force generated when the superconducting coil (3) is displaced from a design position is omitted in FIG.

As described above, since the superconductor magnets (1) are connected at extremely low temperatures, it is possible to support the electromagnetic force acting between the superconductor coil (3) and the iron core (2) with extremely low loss. it can.

[Effects of the Invention] As described above, according to the present invention, different superconductor magnets are connected to each other in a cryogenic state. The strong electromagnetic force acting between each coil and the iron core was balanced to reduce the electromagnetic force transmitted to the outside of the helium container.
Since only the target for the non-equilibrium force generated when the coil deviates from the design position is sufficient, the support rod is thin enough to support the liquid helium with very low loss and to support the liquid helium. The evaporation rate can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, and FIG.
FIG. 3 is a sectional view taken on a plane along the line II-II in FIG. 3, and FIG. 3 is a plan view of a conventional electron storage ring. (1) ... superconducting deflection magnet, (2) ... iron core,
(3) ... superconducting coil, (27) ... helium container,
(28)… Coil winding frame, (29)… Connecting rod. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A superconducting coil, a bobbin for fixing the superconducting coil, an electromagnetic force acting between the ferromagnetic body and a coil of a superconducting magnet made of a ferromagnetic material surrounding the coil and the bobbin, A superconducting coil B constituting a superconducting magnet B installed separately from the magnet, a winding frame B for fixing the superconducting coil B, and a coil B of the superconducting magnet B comprising the coil B and a ferromagnetic material B surrounding the winding frame B And an electromagnetic force B acting between the superconducting magnet B and a superconducting coil, so that the electromagnetic force of the superconducting magnet and the part or all of the electromagnetic force B of the superconducting magnet B are balanced and canceled. A superconducting magnet device, wherein the frame and the superconducting coil winding frame B are connected by a connecting rod having the same temperature as the superconducting coil.