Numerical modelling and AC losses of multifilamentary Bi-2223/Ag conductors with various geometry and filament arrangement

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A validation of the ITER real-time reconstruction algorithms for the plasma current, centroid position, boundary and for the poloidal beta has been performed using the data collected during the first operation of the JT-60SA tokamak. The accuracy of the reconstruction is evaluated against plasma equilibria computed with the CREATE-NL nonlinear code. As it will be shown, although the setup of the magnetic sensors during JT-60SA first operation included a reduced number of sensors compared to what envisaged i

Spin chirality is a fundamental property that manifests non-reciprocal transport—magnetochiral anisotropy (MChA). However, the application of MChA in technology is constrained by the necessity for an external magnetic field, complex non-centrosymmetric crystal synthesis and cryogenic environments. Here we overcome these challenges by imprinting geometric chirality onto a nickel tube via three-dimensional nanoengineering. We use two-photon lithography to create a structurally twisted polymeric template with

Magnetic nulls are locations where the magnetic field vanishes. They determine to a large degree the magnetic connectivity in a system, and are sites of magnetic reconnection. We describe a novel approach to understanding movement, appearance, and disappearance of nulls in magnetic fields. This approach is based on the concept of isotropes, or lines where the field direction is constant. These lines are streamlines of a vector field whose flux is sourced by the topological indices of nulls, and can be conce

The integration of two‐photon lithography (TPL) with magnetic material processing has opened transformative avenues for designing and realizing 3D functional nanomagnetic systems. This review presents a comprehensive overview of how TPL can be leveraged to fabricate 3D architectures that harness magnetism. The fundamental physics of TPL is examined, and recent advances in voxel engineering, resolution, and throughput are reviewed. Emerging strategies for magnetic functionalization, including physical vapor

Magnonics is an exciting and rapidly growing field revolving around the study and manipulation of magnons, the low-lying collective excitations of magnetically ordered systems. This field has emerged in response to both fundamental physics interests and the growing demand for faster, more efficient, and more reliable signal processing and computation up to THz frequencies, i.e., beyond clock frequencies of current computer technology. Magnonic devices promise to transmit and process information in ways that

A non-field aligned coordinate system was recently implemented in GBS, a three-dimensional drift-reduced Braginskii fluid code to simulate turbulence in the plasma periphery of tokamaks. This avoids the singularity present in field-aligned coordinates at the X-point, thus allowing the simulation of any toroidally symmetric magnetic field configuration, with no separation between equilibrium and fluctuating quantities, therefore evolving self-consistently the formation of the plasma profiles. Simulations are

This paper deals with a DC-segmentation of interconnected power systems which represents a relatively new and interesting approach that could be a potential solution for mitigation of the cascading outages effects. The DC-segmentation is defined as the use of DC links to split large AC grids into sets of smaller asynchronously operated AC segments. By implementing grid segmentation, it should be plausible to improve the controllability of power flows, to limit the propagation of disturbances, to reduce the

TORPEX is a basic plasma physics toroidal device located at the CRPP-EPFL in Lausanne. In TORPEX, a vertical magnetic field superposed on a toroidal field creates helicoidal field lines with both ends terminating on the torus vessel. We review recent advances in the understanding and control of electrostatic interchange turbulence, associated structures and their effect on suprathermal ions. These advances are obtained using high-resolution diagnostics of plasma parameters and wave fields throughout the who

Intermittent blobs, which propagate across a confining magnetic fields, are universally observed in natural and laboratory plasmas. In fusion plasmas, cross-field transport of particles and energy are associated, at least in part, with the propagation of blobs, which are therefore of great importance for the design of future fusion reactors. In TORPEX, blobs are generated from ideal interchange modes and, driven by B and curvature-induced charge separation, propagate radially outwards. An analytical blob s

In this paper, we present a new microfabricated fluxgate sensor structure using cascaded planar rings as the ferromagnetic core. The planar ring structures provide closed magnetic excitation loops enabling uniform core saturation with relatively small excitation magnetic field. The magnetic excitation is provided with a rod passing through the ring cores. Planar coils placed under the edges of the core are used as sensing elements. By using this structure, fluxgate sensors having a closed core configuration

We employed electron spin resonance (ESR) technique in the investigation of a series of graphene flakes with different size distributions. Graphene oxide (GO) samples with three distinct size distributions were prepared by the Brodie method. Large flakes of similar to 2500 mu m(2), intermediate size flakes of similar to 1 mu m(2), and small ones of 500 nm(2) have been characterized by ESR in the 4-295 K temperature range. Already for GO flakes the magnetic response strongly varies with their size. Large GO

A key issue for steady-state tokamak operation is to determine the edge conditions that are compatible both with good core confinement and with the power handling and plasma exhaust capabilities of the plasma facing components (PFCs) and divertor systems. A quantitative response to this open question will provide a robust scientific basis for reliable extrapolation of present regimes to an ITER compatible steady-state scenario. In this context, the JET programme addressing steady-state operation is focused

The chapter “Magnetism of low-dimensional metallic structures” reviews experiments on the magnetism of surface-supported low-dimensional structures of 3d metals. Controlling the static and dynamic magnetic behavior of both individual impurities and supported nanostructures on nonmagnetic surfaces represents a fundamental challenge as well as a prerequisite to design magnetic storage and logic devices of novel conception. We describe the governing principles of self-organized growth of metallic nanostructure

The present paper deals with a new approach for the study of the steady-state and transient behavior of three-phase transformers. This approach based on magnetic equivalent circuit-diagrams, takes into account the nonlinear BH curve as well as zero- sequence flux. The nonlinear BH curve is represented by a Fourier series, based on a set of measurement data. For the numerical simulations, two methods have been developed, by considering the total magnetic flux respectively the currents as state variables. Num

Electromagnetic transformers have become obstacles to progress power supply miniaturization. Thus, piezoelectric transformers, which are more compact, immune to magnetic field and that present a high galvanic insulation, become more and more an alternative to electromagnetic transformers. In this paper, two different piezoelectric transformers have been studied and compared: a Rosen type and a radial mode type. The first approach consists in performing an analytical model. This approach is inspired by the t

The current source thyristor inverter is still today a suitable choice for supplying high power adjustable speed drives for pumps or compressors. This paper presents a 12-pulse LCI (load commutated inverter) synchronous drive for a 20 MW compressor, it focuses on the following main aspects: modeling of the complete drive system, numerical simulation and comparison between calculated and measured values of the pulsating torque components in steady-state operations. The modeling of the six- phase synchronous

With the very high electron cyclotron (EC) wave power density achieved in the TCV tokamak, more than 20 MW m(-3), quasilinear modelling predicts an electron cyclotron current drive (ECCD) efficiency well in excess to the experimental value, by up to a factor of 10. Experimentally, radial transport of suprathermal electrons consistent with a diffusion coefficient larger than 1.5 m(2) s(-1) has been observed. This implies that the radial transport time is of the same order as the electron deflection time, sug

We measured polycrystalline samples of SrRuO3 and both superconducting and nonsuperconducting (hydrogen loaded) ruthenocuprates-Eu1.5Ce0.5RuSr2Cu2O10-x (Ru-1222)-samples using ac susceptibility, Ru 3p x-ray photoemission and Ru 2p x-ray-absorption measurements. The superconducting-and metallic-ruthenocuprate samples exhibit significant ferromagnetic fluctuations above the highest magnetic ordering temperature. The (Ru 3p) core level of the SrRuO3, and superconducting ruthenocuprate samples indicate that the

We have measured two structurally similar superconducting systems, RuSr2GdCu2O8 and GdBa2Cu3O7 by means of high-resolution ac susceptibility. The real and the imaginary part of ac susceptibility of both bulk-ceramic and powdered samples have been studied down to the very small magnetic-field levels. We show that there are significant differences in the evolution of superconductivity in the two studied superconducting systems. In particular, we show that the superconducting transition in the grains in RuSr2G

Mono and multifilamentary HTS tapes exhibit non-negligible AC loss in self-field and considerably higher losses in the presence of external magnetic field. The effect of the conductor’s geometry on the AC loss has been investigated in this paper. The nonlinear electromagnetic properties of the superconducting material are expressed with a B-dependent E-J power law and are implemented in Finite Element Method commercial software. The critical current density and the power index n dependence on B are obtained

Numerical modelling and AC losses of multifilamentary Bi-2223/Ag conductors with various geometry and filament arrangement

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Preliminary validation of ITER magnetic diagnostic algorithms by using JT-60SA magnetic measurements

Geometry-induced spin chirality in a non-chiral ferromagnet at zero field

A Topological Approach to Magnetic Nulls

Exploiting Two‐Photon Lithography, Deposition, and Processing to Realize Complex 3D Magnetic Nanostructures

Recent advances in magnonics

Disentangling turbulence in the plasma boundary of diverted tokamaks

Assessment of HVDC grid segmentation for reducing the risk of cascading outages and blackouts

Review and perspectives of electrostatic turbulence and transport studies in the basic plasma physics device TORPEX

Understanding and taming plasma blobs in toroidal magnetized plasmas

A closed core microfluxgate sensor with cascaded planar FeNi rings

Size dependence of the magnetic response of graphite oxide and graphene flakes - an electron spin resonance study

Development of steady-state scenarios compatible with ITER-like wall conditions

Magnetism of Low-dimensional Metallic Structures

Improved modeling of three-phase transformer analysis based on nonlinear BH curve and taking into account zero-sequence flux

Modeling and characteristics comparison of two different piezoelectric transformers

12-Pulse LCI synchronous drive for a 20 MW compressor : modeling, simulation and measurements

Modelling of the electron cyclotron current drive experiments in the TCV tokamak

Magnetic interactions and electronic states in superconducting and nonsuperconducting ruthenocuprates

Superconducting transition in ruthenocuprate RuSr2GdCu2O8 viewed from the studies of the imaginary part of ac susceptibility

Effect of the geometry of HTS on AC loss by using finite element method simulation with B-dependent E-J power law