Abstract: A self-shield open magnetic resonance imaging superconducting magnet comprises five pairs of coils: shim coils, first main magnetic coils, second main magnetic coils, third main magnetic coils, and shielding coils. The five pairs of coils are symmetric about the center. The shim coils are arranged closest to the center point; the first main magnetic coils, the second main magnetic coils, the third main magnetic coils, and the shielding coils are arranged in sequence outside. The first main magnetic coils are connected with reverse current. The second and third main magnetic coils are connected with positive current for providing the main magnetic field strength. The shim coils are connected with positive current for compensating the magnetic field in the central region. The shielding coils are connected with reverse current for creating a magnetic field opposite to the main magnetic field for compensating the stray magnetic field in the space.

Abstract: A superconducting magnet system for nuclear magnetic resonance with a high magnetic field and a high degree of homogeneity of magnetic field is provided. The system comprises a main coil and a magnetic field homogeneity compensating coil having a combination of a forward current and a reverse current, and is composed of 24 superconducting coils formed by winding NbTi/Cu low-temperature superconducting wires. The system can produce a magnetic field of 9.4 T within a room-temperature space of 800 mm and can obtain a degree of non-homogeneity of magnetic field less than 0.1 ppm within a spherical volume of 300 mm. The system is equipped with a superconducting magnet inside, and a low-temperature vessel for liquid helium provides a low-temperature environment of 4K which is required for the normal operation of the superconducting magnet. A ferro-magnetic shielding system enables the system to have a good electromagnetic compatibility.

Abstract: A free liquid helium volatilization superconductive magnetic suspension device includes a low temperature container, a refrigeration, a cold screen, a liquid helium container, a superconductive rotor, a suspension coil, a rotor chamber, a liquid tube, a condenser and a pole-axis displacement sensor. The heat generated by the wires of the suspension coil can be prevented transferring to the liquid helium container by the room temperature current lead joint, the high temperature superconducting current lead joint and low temperature superconducting current lead joint. Therefore the volatilization of the liquid helium in the liquid helium container can be reduced. The status of free liquid helium volatilization in the liquid helium container can be reached through refrigeration cooling condenser to liquefy the helium. The device needs not to be input the liquid helium time after time and can run independently for a long term.

Abstract: A self-shield open magnetic resonance imaging superconducting magnet comprises five pairs of coils: shim coils, first main magnetic coils, second main magnetic coils, third main magnetic coils, and shielding coils. The five pairs of coils are symmetric about the center. The shim coils are arranged closest to the center point; the first main magnetic coils, the second main magnetic coils, the third main magnetic coils, and the shielding coils are arranged in sequence outside. The first main magnetic coils are connected with reverse current. The second and third main magnetic coils are connected with positive current for providing the main magnetic field strength. The shim coils are connected with positive current for compensating the magnetic field in the central region. The shielding coils are connected with reverse current for creating a magnetic field opposite to the main magnetic field for compensating the stray magnetic field in the space.

Abstract: A high magnetic field superconducting magnet system with large crossing warm bore is disclosed, a superconducting coil thereof includes a low temperature superconducting coil and a high temperature superconducting coil. The superconducting coils are connected to a thermal shield and a flange of a low temperature container by a supporting drawbar, thus the superconducting coils as a whole are supported inside the low temperature container. A thermal switch is connected to a primary cold head and a secondary cold head of the cryocooler. The secondary cold head of the cryocooler is connected to a magnet-reinforced supporting flange at the two ends of the low temperature superconducting coil and the high temperature superconducting coil by a cold conduction strip. The superconducting magnet system has a room temperature bore in horizontal direction and a room temperature bore in vertical direction.

Abstract: A superconducting magnet system for nuclear magnetic resonance with a high magnetic field and a high degree of homogeneity of magnetic field is provided. The system comprises a main coil and a magnetic field homogeneity compensating coil having a combination of a forward current and a reverse current, and is composed of 24 superconducting coils formed by winding NbTi/Cu low-temperature superconducting wires. The system can produce a magnetic field of 9.4 T within a room-temperature space of 800 mm and can obtain a degree of non-homogeneity of magnetic field less than 0.1 ppm within a spherical volume of 300 mm. The system is equipped with a superconducting magnet inside, and a low-temperature vessel for liquid helium provides a low-temperature environment of 4K which is required for the normal operation of the superconducting magnet. A ferro-magnetic shielding system enables the system to have a good electromagnetic compatibility.

Abstract: A high magnetic field superconducting magnet system with large crossing warm bore is disclosed, a superconducting coil thereof includes a low temperature superconducting coil and a high temperature superconducting coil. The superconducting coils are connected to a thermal shield and a flange of a low temperature container by a supporting drawbar, thus the superconducting coils as a whole are supported inside the low temperature container. A thermal switch is connected to a primary cold head and a secondary cold head of the cryocooler. The secondary cold head of the cryocooler is connected to a magnet-reinforced supporting flange at the two ends of the low temperature superconducting coil and the high temperature superconducting coil by a cold conduction strip. The superconducting magnet system has a room temperature bore in horizontal direction and a room temperature bore in vertical direction.