[en] For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T. Compaction was achieved by pressing the punches between the closed end of the press tube and the hydraulic cylinder mounted on the opposite end. Improvements up to 10% in magnetization and 20% in energy products of the permanent magnets were obtained, as the alignment fields were increased above the 2-T maximum field of the electromagnets used in industry. Increases in magnetization of 3% are significant in the mature sintered magnet industry

[en] The properties of currently available NbTi superconductor and carbon-fiber structural materials enable the possibility of constructing a magnetically levitated space elevator from the earth's surface up to an altitude of(approx) 200 km. The magnetic part of the elevator consists of a long loop of current-carrying NbTi, composed of one length that is attached to the earth's surface in an east-west direction and a levitated-arch portion. The critical current density of NbTi is sufficiently high that these conductors will stably levitate in the earth's magnetic field. The magnetic self-field from the loop increases the levitational force and for some geometries assists levitational stability. The 200-km maximum height of the levitated arch is limited by the allowable stresses of the structural material. The loop is cryogenically cooled with helium, and the system utilizes intermediate pumping and cooling stations along both the ground and the levitated portion of the loop, similar to other large terrestrial cryogenic systems. Mechanically suspended from the basic loop is an elevator structure, upon which mass can be moved between the earth's surface and the top of the loop by a linear electric motor or other mechanical or electrical means. At the top of the loop, vehicles may be accelerated to orbital velocity or higher by rocket motors, electromagnetic propulsion, or hybrid methods

[en] Tests were conducted to determine the electrical and magnetic characteristics of a superconductor shielded core reactor (SSCR). The results show that a closed-core SSCR is predominantly a resistive device and an open-core SSCR is a hybrid resistive/inductive device. The open-core SSCR appears to dissipate less than the closed-core SSCR. However, the impedance of the open-core SSCR is less than that of the closed-core SSCR. Magnetic and thermal diffusion are believed to be the mechanism that facilitates the penetration of the superconductor tube under fault conditions

No abstract available

[en] Commercial-grade magnet powder (Magnequench UG) was uniaxial die-pressed into cylindrical compacts, while being aligned in the 1-T to 8-T DC field of a superconducting solenoid at Argonne National Laboratory. Then, the compacts were added to normal Magnequench UG production batches for sintering and annealing. The variations in magnet properties for different strengths of alignment fields are reported for 15.88-mm (5/8-in.) diameter compacts made with length-to-diameter (L/D) ratios in the range (ge) 0.25 and (le) 1. The best magnets were produced when the powder-filled die was inserted into the active field of the solenoid and then pressed. Improvements in the residual flux density of 8% and in the energy product of 16% were achieved by increasing the alignment field beyond the typical 2-T capabilities of electromagnets. The most improvement was achieved for the compacts with the smallest L/D ratio. The ability to make very strong magnets with small L/D, where self-demagnetization effects during alignment are greatest, would benefit most the production of near-final-shape magnets. Compaction of the magnet powder using a horizontal die and a continuously active superconducting solenoid was not a problem. Although the press was operated in the batch mode for this proof-of-concept study, its design is intended to enable automated production

[en] The rotational dynamics of a disc-shaped permanent magnet rotor levitated over a high temperature superconductor was studied experimentally and theoretically. The interaction between the rotor magnet and the superconductor was modelled by assuming the magnet to be a magnetic dipole and the superconductor a diamagnet. In the magnetomechanical analysis of the superconductor part, the frozen image concept was combined with the diamagnetic image, and the damping in the system was neglected. The interaction potential of the system is the combination of magnetic and gravitational potentials. From the dynamical analysis the equations of motion of the permanent magnet were stated as a function of lateral, vertical, tilt, precision and rotating angles. The vibration behaviour and correlation of the vibration of one direction with that of another were determined with a numerical calculation based on the Runge-Kutta method. The various vibrational frequencies identified were vertical, radial, tilt, precession and rotation. The tests performed for experimental verifications were translational and rotational. The permanent magnet was 'spun up' under vacuum conditions to analyse the dynamics of the free 'spin down' behaviour of the permanent magnet

[en] An overview summary of recent Boeing work on high-temperature superconducting (HTS) bearings is presented. A design is presented for a small flywheel energy storage system that is deployable in a field installation. The flywheel is suspended by a HTS bearing whose stator is conduction cooled by connection to a cryocooler. At full speed, the flywheel has 5 kW h of kinetic energy, and it can deliver 3 kW of three-phase 208 V power to an electrical load. The entire system, which includes a containment structure, is compatible with transportation by forklift or crane. Laboratory measurements of the bearing loss are combined with the parasitic loads to estimate the efficiency of the system. Improvements in structural composites are expected to enable the operation of flywheels with very high rim velocities. Small versions of such flywheels will be capable of very high rotational rates and will likely require the low loss inherent in HTS bearings to achieve these speeds. We present results of experiments with small-diameter rotors that use HTS bearings for levitation and rotate in vacuum at kHz rates. Bearing losses are presented as a function of rotor speed.

[en] Most large-scale applications of high-critical-temperature superconductors will require wires or tapes that can carry large current in applied magnetic fields. This report describes research and development efforts at Argonne National Laboratory (ANL) aimed at producing practical superconducting components and devices using the Y-Ba-Cu-O and Bi-(Pb)-Sr-Ca-Cu-O systems. Topics discussed include various methods of forming second- and first-generation composite conductors, characterization of their structures and superconducting and mechanical properties, modeling of grain-boundary current transport, and the testing and modeling of a superconducting fault current limiter