Related papers: Minimax Current Density Coil Design
While electrons moving perpendicular to a magnetic field are confined to cyclotron orbits, they can move freely parallel to the field. This simple fact leads to complex current flow in clean, low carrier density semi-metals, such as…
We use thermal noise induced currents to image the real and imaginary parts of the conductivity of a body. Covariances of the thermal noise currents measured at a few electrodes are shown to be related to a deterministic problem. We use the…
Presently, Magnetic Resonance Imaging (MRI) magnets must deliver excellent magnetic field (B0) uniformity to achieve optimum image quality. Long magnets can satisfy the homogeneity requirements but require considerable superconducting…
Materials with charged chiral quasiparticles in external parallel electric and magnetic fields can support an electric current that grows linearly in time, corresponding to diverging DC conductivity. From experimental viewpoint, this…
Roebel cables made of HTS coated conductors can carry high currents with a compact design and reduced AC losses. They are therefore good candidates for manufacturing coils for HTS applications such as motors and generators. In this paper we…
Ultra-thin magnetic tunnel junctions with low resistive MgO tunnel barriers are prepared to examine their stability under large current stress. The devices show magnetoresistance ratios of up to 110 % and an area resistance product of down…
A general scheme for increasing the difference in magnetic flux density between a high and a low magnetic field region by removing unnecessary magnet material is presented. This is important in, e.g., magnetic refrigeration where magnet…
The behaviour of superconducting junctions of SNINS-type (where S is superconductor, N is normal metal, I is insulator) with anharmonic current-phase relations in the external magnetic field near the critical temperature was investigated.…
The distribution of the transport current in a superconducting filament aligned parallel to the flat surface of a semi-infinite bulk magnet is studied theoretically. An integral equation governing the current distribution in the Meissner…
The ability to conduct electric current without dissipating energy is a property of superconductors that is used in magnetic systems utilized in healthcare, natural sciences, and ongoing global projects in nuclear fusion and aviation. The…
A theorem on the magnetic energy minimum in a perfect, or ideal, conductor is proved. Contrary to conventional wisdom the theorem provides a classical explanation of the expulsion of a magnetic field from the interior of a conductor that…
The implementation of the 2nd generation high-Tc superconductors in power applications, such as electrical transformers, motors and generators requires superconducting wires that are superior to copper Litz wires at cryogenic temperatures…
The problem of determining a current density confined to a volume from measurements of the magnetic field it produces exterior to that volume is known to have non-unique solutions. To uniquely determine the current density, or the…
A method to measure the electrical connectivity between square superconducting plates joined by weak link interfaces is presented. It is based on observation of lines where the flow of critical current abruptly changes direction due to the…
We present an experimental study of the effects of driving current direction on ferromagnetic resonance in NiFe foils. The rf driving current was applied to NiFe foils of different shapes. In rectangular samples with a close-to-uniform flow…
We present a general theory of current deviations in straight current carrying wires with random imperfections, which quantitatively explains the recent observations of organized patterns of magnetic field corrugations above micron-scale…
Magnetic field source localization and imaging happen at different scales. The sensing baseline ranges from meter scale such as magnetic anomaly detection, centimeter scale such as brain field imaging to nanometer scale such as the imaging…
Here we present designs for a static septum magnet with two adjacent apertures where ideally one aperture has a uniform dipole field and the other zero field. Two designs are considered. One is a true septum magnet with a thin layer of…
Controllers for motor drives typically require a current reference which will satisfy the requested torque subject to system constraints. This work generalizes existing current reference theory to the case of the Wound Rotor Synchronous…
In the present work we argue that the usual assumption that magnetic currents possess the vector structure characteristic of electric currents may be the source of several difficulties in the theory of magnetic monopoles. We propose an {\it…