Abstract: An intelligent liquid helium-free whole-body magnetic resonance imaging superconducting magnet system, comprising: a vacuum container, provided with a main magnetic field superconducting coil in a radially inner side position therein, and a shielding superconducting coil in a radially outer side position therein, and a heat pipe gas tank is arranged in a vacant area between the main magnetic field superconducting coil and the shielding superconducting coil; a liquid helium reservoir, communicated with a liquid-gas storage tank, and connected with the main magnetic field superconducting coil or the shielding superconducting coil via a helium self-oscillation heat pipe; a refrigerator, fixed on the vacuum container through a thermal conduction component auto-pluggable component; the first thermal conduction component connected with the refrigerator is in close contact with the thermal radiation screen assembly, and the second thermal conduction component connected with the refrigerator is in close contact with

Abstract: The present application provides a method of designing a high shielding gradient coil for a planar superconducting magnetic resonance imaging (MRI) system and a gradient coil thereof, the method determines a shielding area according to an outer profile of a metal conductor around the position of the gradient coil in the planar superconducting MRI system, and performs partitioned shielding of a stray field. The constraint values of stray fields at different partitioned zones of the shielding area are adjusted according to the shielding requirements. The primary coils of both the transverse gradient coil and the longitudinal gradient coil optimized by the design method of the high shielding gradient coil contain a reverse coil, which generates a magnetic field that offsets leakage magnetic field of other coils, thus achieving the purpose of reducing the stray field of the gradient coil.

Abstract: The present application provides a method of designing a high shielding gradient coil for a planar superconducting magnetic resonance imaging (MRI) system and a gradient coil thereof, the method determines a shielding area according to an outer profile of a metal conductor around the position of the gradient coil in the planar superconducting MRI system, and performs partitioned shielding of a stray field. The constraint values of stray fields at different partitioned zones of the shielding area are adjusted according to the shielding requirements. The primary coils of both the transverse gradient coil and the longitudinal gradient coil optimized by the design method of the high shielding gradient coil contain a reverse coil, which generates a magnetic field that offsets leakage magnetic field of other coils, thus achieving the purpose of reducing the stray field of the gradient coil.

Abstract: Provided is a gravity gradient measurement apparatus and measuring method, wherein a turntable rotates horizontally around an earth-vertical axis, a vacuum layer is arranged on the turntable defining a first chamber, a first three-axis accelerometer and a second three-axis accelerometer are located in the first chamber, the first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an x axis with respect to an origin of coordinates. Both the first three-axis accelerometer and the second three-axis accelerometer have a distance of R from the origin of coordinates. The first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an z axis with respect to the origin of coordinates, and the first three-axis accelerometer and the second three-axis accelerometer are spaced at a distance of h on the z axis. The measurement module uses measurements of the accelerometers to determine gravity gradients on the coordinate axes.

Abstract: The present disclosure relates to a testing device comprising a bracket including a first groove and a second groove parallel to each other, wherein the first groove and the second groove run through an inner surface of the bracket perpendicularly to a thickness direction of the testing device; a plate assembly including a first plate and a second plate parallel to each other, wherein the first plate is disposed within the first groove and fits closely within the first groove along a length direction and a thickness direction of the testing device, the second plate is disposed within the second groove, with a gap present in the second groove along a length direction and/or a thickness direction of the testing device; a connector array including a plurality of connector assemblies disposed on the plate assembly in a predetermined pattern, wherein each of the plurality of connector assemblies is connected between the first plate and the second plate; and a displacing tool disposed on the bracket and/or the plat

Abstract: An intelligent liquid helium-free whole-body magnetic resonance imaging superconducting magnet system, comprising: a vacuum container, provided with a main magnetic field superconducting coil in a radially inner side position therein, and a shielding superconducting coil in a radially outer side position therein, and a heat pipe gas tank is arranged in a vacant area between the main magnetic field superconducting coil and the shielding superconducting coil; a liquid helium reservoir, communicated with a liquid-gas storage tank, and connected with the main magnetic field superconducting coil or the shielding superconducting coil via a helium self-oscillation heat pipe; a refrigerator, fixed on the vacuum container through a thermal conduction component auto-pluggable component; the first thermal conduction component connected with the refrigerator is in close contact with the thermal radiation screen assembly, and the second thermal conduction component connected with the refrigerator is in close contact with

Abstract: The present disclosure relates to a testing device comprising a bracket including a first groove and a second groove parallel to each other, wherein the first groove and the second groove run through an inner surface of the bracket perpendicularly to a thickness direction of the testing device; a plate assembly including a first plate and a second plate parallel to each other, wherein the first plate is disposed within the first groove and fits closely within the first groove along a length direction and a thickness direction of the testing device, the second plate is disposed within the second groove, with a gap present in the second groove along a length direction and/or a thickness direction of the testing device; a connector array including a plurality of connector assemblies disposed on the plate assembly in a predetermined pattern, wherein each of the plurality of connector assemblies is connected between the first plate and the second plate; and a displacing tool disposed on the bracket and/or the plat

Abstract: Provided is a gravity gradient measurement apparatus and measuring method, wherein a turntable rotates horizontally around an earth-vertical axis, a vacuum layer is arranged on the turntable defining a first chamber, a first three-axis accelerometer and a second three-axis accelerometer are located in the first chamber, the first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an x axis with respect to an origin of coordinates. Both the first three-axis accelerometer and the second three-axis accelerometer have a distance of R from the origin of coordinates. The first three-axis accelerometer and the second three-axis accelerometer are arranged symmetrically on an z axis with respect to the origin of coordinates, and the first three-axis accelerometer and the second three-axis accelerometer are spaced at a distance of h on the z axis. The measurement module uses measurements of the accelerometers to determine gravity gradients on the coordinate axes.

Abstract: A strong-magnetic focused magnet system with a terahertz source includes a first superconducting main coil and a second superconducting main coil. The second superconducting main coil surrounds the outer surface of the first superconducting main coil, and the second superconducting main coil is coaxial with the first superconducting main coil.

Abstract: A strong-magnetic focused magnet system with a terahertz source includes a first superconducting main coil and a second superconducting main coil. The second superconducting main coil surrounds the outer surface of the first superconducting main coil, and the second superconducting main coil is coaxial with the first superconducting main coil.

Abstract: A device and a method for inhibiting vibration of a superconducting magnetic suspension rotor. The device comprises a rotor cavity housing, lateral coils, a superconducting rotor with a rotor top plane, a copper plate, pole shoes, a z-axial vibration measuring sensor, an x-axial vibration measuring sensor, a y-axial vibration measuring sensor, and a copper ring, the pole shoes having a spherical inner surface and being arranged symmetrically up and down so as to form a rotor cavity; the annular lateral coils being closely adjacent to an outside cylindrical surface of the rotor cavity housing and fixed to the same; the z-axial vibration measuring sensor being fixed to a central region of the copper plate; the x-axial vibration measuring sensor being mounted along an x-coordinate axis and the y-axial vibration measuring sensor mounted on a on the copper ring which is mounted along an equatorial plane of the rotor.

Abstract: A superconducting magnet system for head imaging is disclosed which includes a cryocooler, a high-pressure helium container, a self-excitation heat pipe and a superconducting magnet. A second stage coldhead of the cryocooler is connected to the high-pressure helium container for converting the helium gas in the high-pressure helium container into liquid helium. The self-excitation heat pipe forms a closed cooling loop, and liquid helium in the high-pressure helium container flows circularly in the self-excitation heat pipe. The self-excitation heat pipe cools the superconducting magnet, wherein part of the liquid helium in the self-excitation heat pipe is converted into the helium gas due to the heat disturbance generated by the superconducting magnet, and the helium gas interacts with the liquid helium to generate liquid helium vibration.

Abstract: A low-temperature superconducting device for measuring gravity, includes a low-temperature container, a cryocooler, a rotor chamber, a superconducting rotor, an upper levitation coil, a lower levitation coil, an upper electrode, an intermediate electrode, a lower electrode, a magnetic shielding chamber and a superconducting quantum interference device. By cooling the whole low-temperature superconducting device using a cryocooler, the intermediate electrode disposed in the body of the magnetic shielding chamber will generate an output voltage when the superconducting rotor is displaced due to a change of gravity. Thus, the superconducting quantum interference device can make the superconducting rotor return to the central balance position by adjusting the operating current of the upper levitation coil or the lower levitation coil. A change of gravity can be determined based on the operating current fed back to the upper levitation coil or the lower levitation coil.

Abstract: An open type nuclear magnetic resonance magnet system having an iron ring member. A superconducting coil and a superconducting switch form a closed-loop current circuit to generate a magnetic field. The generated magnetic field gains a magnetic flux circuit and executes magnetic field shielding through upper and lower iron yokes and a lateral iron yoke. The magnet system generates a desired magnetic field in a magnet imaging central area via the superconducting coil. To balance the extremely high electromagnetic force between the superconducting coil and the upper and lower iron yokes, an annular iron ring is mounted in a space defined by an inner perimeter wall of in a cryogenic container. The magnetic field distribution between the superconducting coil and the upper and lower iron yokes is changed via the iron ring, so that the electromagnetic interaction force therebetween is reduced.

Abstract: A superconducting magnet system for head imaging is disclosed which includes a cryocooler, a high-pressure helium container, a self-excitation heat pipe and a superconducting magnet. A second stage coldhead of the cryocooler is connected to the high-pressure helium container for converting the helium gas in the high-pressure helium container into liquid helium. The self-excitation heat pipe forms a closed cooling loop, and liquid helium in the high-pressure helium container flows circularly in the self-excitation heat pipe. The self-excitation heat pipe cools the superconducting magnet, wherein part of the liquid helium in the self-excitation heat pipe is converted into the helium gas due to the heat disturbance generated by the superconducting magnet, and the helium gas interacts with the liquid helium to generate liquid helium vibration.

Abstract: A low-temperature superconducting device for measuring gravity, includes a low-temperature container, a cryocooler, a rotor chamber, a superconducting rotor, an upper levitation coil, a lower levitation coil, an upper electrode, an intermediate electrode, a lower electrode, a magnetic shielding chamber and a superconducting quantum interference device. By cooling the whole low-temperature superconducting device using a cryocooler, the intermediate electrode disposed in the body of the magnetic shielding chamber will generate an output voltage when the superconducting rotor is displaced due to a change of gravity. Thus, the superconducting quantum interference device can make the superconducting rotor return to the central balance position by adjusting the operating current of the upper levitation coil or the lower levitation coil. A change of gravity can be determined based on the operating current fed back to the upper levitation coil or the lower levitation coil.

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 process for fabricating an ultra-low-resistance superconducting joint that has high shielding characteristics. The process includes: corroding copper on the outer surface at the end of a NbTi/Cu superconducting wire to form terminal NbTi superconducting filaments; inserting same number of NbTi superconducting filaments into each through hole of the niobium layer of a Nb/NbTi/Cu multilayer composite rod; pressing at the outside of the Nb/NbTi/Cu multilayer composite rod to combine the Nb/NbTi/Cu multilayer composite rod and NbTi superconducting filaments together to form a joint; and inserting the joint into a YBCO tube, and then filling the YBCO tube with molten bismuth-lead-tin-cadmium (BiPbSnCd) alloy solder to form a superconducting joint with high shielding and low resistance characteristics.