An apparatus includes a chamber and a bulk superconductor disposed within the chamber. The apparatus also includes a heating element coupled to the bulk superconductor.

A superconducting magnetic energy storage system (SMES). The SMES includes a toroidally wound super conducting magnet having a toroidal magnetic core with a charging winding and a discharging winding. The charging winding and discharging winding are wound on the toroidal magnetic core. The SMES also includes a DC power source, the DC power source operable to provide DC current to the charging winding of the toroidally wound superconducting magnet, and a modulator operably connected to the DC power source and the charging winding, the modulator operable to modulate at least a portion of the DC current applied to the charging winding of the superconducting magnet. The energy is stored in a magnetic field of the superconducting magnet by applying a current to the charging winding of the superconducting magnet, and energy is withdrawn from the magnetic field by a current flowing in the discharging winding.

A superconducting magnetic energy storage system (SMES). The SMES includes a toroidally wound super conducting magnet having a toroidal magnetic core with a charging winding and a discharging winding. The charging winding and discharging winding are wound on the toroidal magnetic core. The SMES also includes a DC power source, the DC power source operable to provide DC current to the charging winding of the toroidally wound superconducting magnet, and a modulator operably connected to the DC power source and the charging winding, the modulator operable to modulate at least a portion of the DC current applied to the charging winding of the superconducting magnet. The energy is stored in a magnetic field of the superconducting magnet by applying a current to the charging winding of the superconducting magnet, and energy is withdrawn from the magnetic field by a current flowing in the discharging winding.

A system for applying a force or pre-stress to a portion of a toroidal field coil may include a structure having a first arm including a first arm gap wall and a second arm including a second arm gap wall. The structure may include an arcuate space separating the first arm and the second arm. The structure may include a bean-shaped opening configured to surround the toroidal field coil. An expandable container may be positioned between the first arm gap wall and the second arm gap wall. A liquid within the expandable container may expand upon freezing.

Example coil guns and methods of using coil guns are described herein. An example coil gun includes a first pancake module; a second pancake module, where the first pancake module and the second pancake module are each formed of a winding with an inner superconducting material layer and an outer ordinary conductor layer, where the first pancake module and the second pancake module are physically and/or inductively coupled to propagate a quench of a superconducting state of the first pancake module to the second pancake module.

An apparatus includes an electrically conductive coil which produces a magnetic field when an electrical current passes therethrough; a selectively activated persistent current switch connected across the electrically conductive coil; a cryostat having the electrically conductive coil and the persistent current switch disposed therein; an energy dump; at least one sensor which detects an operating parameter of the apparatus and outputs at least one sensor signal in response thereto; and a magnet controller. The magnet controller receives the sensor signal(s) and in response thereto detects whether an operating fault (e.g. a power loss to the compressor of a cryocooler) exists in the apparatus, and when an operating fault is detected, connects the energy dump unit across the electrically conductive coil to transfer energy from the electrically conductive coil to the energy dump unit. The energy dump unit disperses the energy outside of the cryostat.

A method for charging a superconducting-switch-free superconductively closed circuit with a sub-circuit comprising an entry connection area (6a) and an exit connection area (6b) dividing the sub-circuit into a first branch (1) with a first inductance L1 and a second branch (2) with a second inductance L2, and currents leads (3), comprising: Choosing the positions of the connection areas (6a, 6b) and/or the geometry of the branches (1, 2) and/or the cross sections of the branches (1, 2) such that the first inductance L1 is lower than the second inductance L2; modifying an initial current I0 (I0?0) by feeding a supply current Iin into the circuit comprising: 10(a) Increasing the supply current until a first partial current in one branch reaches the critical current, (b) Further increasing the supply current to ?a resulting in a second partial current in the other branch, (c) Reducing the supply current Iin to 0A, resulting in a remanent circuit current within the circuit.

The present invention provides a rare earth cold accumulating material particle comprising a rare earth oxide or a rare earth oxysulfide, wherein the rare earth cold accumulating material particle is composed of a sintered body; an average crystal grain size of the sintered body is 0.5 to 5 ?m; a porosity of the sintered body is 10 to 50 vol. %; and an average pore size of the sintered body is 0.3 to 3 ?m. Further, it is preferable that the porosity of the rare earth cold accumulating material particle is 20 to 45 vol. %, and a maximum pore size of the rare earth cold accumulating material particle is 4 m or less. Due to this structure, there can be provided a rare earth cold accumulating material having a high refrigerating capacity and a high strength.

The present invention provides a rare earth cold accumulating material particle comprising a rare earth oxide or a rare earth oxysulfide, wherein the rare earth cold accumulating material particle is composed of a sintered body; an average crystal grain size of the sintered body is 0.5 to 5 ?m; a porosity of the sintered body is 10 to 50 vol. %; and an average pore size of the sintered body is 0.3 to 3 ?m. Further, it is preferable that the porosity of the rare earth cold accumulating material particle is 20 to 45 vol. %, and a maximum pore size of the rare earth cold accumulating material particle is 4 ?m or less. Due to this structure, there can be provided a rare earth cold accumulating material having a high refrigerating capacity and a high strength.

An apparatus includes a chamber and a bulk superconductor disposed within the chamber. The apparatus also includes a heating element coupled to the bulk superconductor.