The transient behavior of high temperature superconducting (HTS) cables could significantly depends on fault parameters. This paper investigates impact of fault resistance, fault type, and fault duration time on the transient behavior of a 22.9 kV HTS AC cable. To accomplish this, an equivalent circuit model (ECM) is established to model transient and steady state behaviors of understudied cable, while

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 presence of weak links, and the confinement created by the shape of the sample. The method is demonstrated using magneto-optical imaging (MOI) of systems consisting

The transition from the superconducting to the normal state in a magnetic field was considered as a irreversible thermodynamic process before 1933 because of Joule heating. But all physicists became to consider this transition as reversible after 1933 because of the obvious contradiction of the Meissner effect with the second law of thermodynamics if this transition is considered as a irreversible

We have investigated the dynamics of dissipative states in NbTi superconducting thin films using electrical step pulse excitations on a sapphire substrate close to Tc. Excitation of a superconducting wire with a current pulse larger than the depairing critical current, Ic, gives rise to a non-equilibrium superconducting state. We identified two dissipative states, the hotspot (HS) and the phase slip

High temperature conventional superconductivity in hydrogen-rich materials under high pressure has been reportedly found in twelve different compounds in recent years. However, the experimental evidence on which these claims are based has recently been called into question. Here we discuss the measurement of trapped magnetic flux, that should establish definitively that these materials are indeed high

Anvil tests are effective for determination of the mechanical delamination strength (MDS) of 2G high temperature superconducting coated conductors (CCs), which has been widely used. However, the discrete property of measurement data makes the MDS of CCs hard to evaluate just from the average and variance. To properly provide an analysis of these discrete experimental data, the three-parameter Weibull

Experimental data from the recently discovered iron-based superconductor (IBS) KCa2Fe4As4F2 is analyzed within a realistic five-band s± Eliashberg model with coupling provided by antiferromagnetic spin fluctuations. Fundamental parameters are deduced from available angle resolved photoemission spectoscopy (ARPES) and ab-initio density functional theory (DFT) data, and several physical properties are

The paper we presented is essentially the logical conclusion of a large-scale work - from developing a strategy for detecting topological BKT phase transitions in a Josephson medium of granular high-temperature superconductors to establishing the identity of topological phases arising from two fundamentally different types of external influence. The work is devoted to the study of the topological phases

Based on the Green’s function method, we study theoretically the Josephson effect and pair correlations in an s-wave Josephson junction with a ferromagnetic trilayer (SF1F2F3S). The Green’s functions satisfying the Gor’kov equations are calculated numerically without taking the quasiclassical approximation. We focus on the typical case where the left and right ferromagnetic layers are the same (SF1F2F1S)

The quasiclassical equations in the t-representation for the matrix Green’s functions with different arguments are derived in order to study the superconducting tunnel junctions based on two-gap superconductors. The current density expression in terms of the Green’s functions in the t-representation are derived. The problem is solved in the framework of the model with the piecewise constant order parameters

The Heusler compound ScInAu2 was previously reported to have a superconducting ground state with a critical temperature of 3.0K. Recent high throughput calculations have also predicted that the material harbors a topologically non-trivial band structure similar to that reported for β-PdBi2. In an effort to explore the interplay between the superconducting and topological properties properties, electrical

We have investigated vortex structures in three-dimensional superconductors under a helical magnetic field from a chiral helimagnet numerically. In order to obtain vortex structures, we solve the three-dimensional Ginzburg-Landau equations with the finite element method. A spatial distribution of the helical magnetic field corresponds to a spatial distribution of magnetic moments in the chiral helimagnet

A hydraulic analysis is promising to perceive the complex turbulent flow behavior of sub-cooled liquid nitrogen (LN2) through counter flow cold dielectric high temperature superconducting (HTS) cables. Such counter flow HTS cables comprise of an annular (cryostat) and a central corrugated pipe separated by a HTS conductor layer. Flow of sub-cooled liquid nitrogen through central and annular corrugated

We have studied how the current-voltage (IV) characteristic below the critical temperature gets affected by electron doping in Eu1-xCexBa2Cu3O7-δ (ECBCO) superconducting systems. The critical current density as a function of T has been extracted in the vicinity but below the critical temperature. Variation of the low critical current density with temperature in the limited range of T has been explained

A consistent microscopic theory of superconductivity for strongly correlated electronic systems is presented within the extended t–J–V model where the intersite Coulomb repulsion and the electron-phonon interaction are taken into account. The exact Dyson equation for the normal and anomalous (pair) Green functions is derived for the projected (Hubbard) electronic operators. The equation is solved in

In this study, an extended A-V formulation is used to determine the alternating current (AC) losses of a coil made of high temperature superconducting (HTS) tape. The current is the same at each turn by balancing the voltages of each turn. By this modification, this method can be applied in a wide application area. This method also provides the chance to determine the calculations at currents higher

The present paper determines the properties of the transmission spectrum in a quasi-periodic one-dimensional photonic crystal. The photonic crystal is composed of a high-temperature superconductor (HgBa2Ca2Cu3O8+δ) and a semiconductor (GaAs). These materials are arranged based on the Rudin Shapiro sequence. Additionally, this study also considers the effects of temperature and pressure on the optical

It was recently pointed out that so-called “superhydrides”, hydrogen-rich materials that appear to become superconducting at high temperatures and pressures, exhibit physical properties that are different from both conventional and unconventional standard type I and type II superconductors [1,2]. Here we consider magnetic field expulsion in the first material in this class discovered in 2015, sulfur

In this paper, we used the density functional theory based on GGA-PBE approximation, to reconsider the stability of CaH6 in phase cI14, which corresponds to the superconducting state according to some theoretical study. Our motivation for reconsidering is the conflict between an experimental and theoretical result about the stability of CaH6 in the superconducting phase under high stress. The obtained

We report on the testing of a 1 m long and 0.5 m wide racetrack coil wound from 4.5 km of MgB2 tape-shaped superconductors with a copper strip soldered to the nickel matrix. The cross-section of the coil corresponds to what is needed for the field windings of a 10 MW direct drive wind turbine generator pole, but where the straight section has been shortened. Ten double pancake sub-coils were wet-wound

We measured the two-dimensional magnetic field dependence of a Josephson current by applying external magnetic fields Hx and Hy parallel to the plane of a Nb/Al-AlOx/Nb Josephson junction from two directions. In addition, we measured the modulation characteristics of the Josephson current by applying a magnetic field Hz in the direction perpendicular to the plane of the junction. When the perpendicular

The present investigations deal with the study of the isotope effect in bilayer cuprate superconductors. We have considered the BCS-effective Hamiltonian that includes the intra and inter-layer kinetic energies and in plane attractive interaction responsible for pairing in these systems. In order to look for pseudo-gap having momentum dependence of the form of d-wave superconducting order parameter

Superconducting (SC) electrical machines could affect different industries due to their high power density. The most promising of them are fully superconducting machines. In the paper whole cycle of development of fully high temperature superconducting electrical machine is described: analytical calculation of magnetic field in the active zone of the machine, finite element modeling, some design features

We report the enhanced superconducting properties of double-chain based superconductor Pr2Ba4Cu7O15−δ synthesized by the citrate pyrolysis technique. The reduction heat treatment in vacuum results in the appearance of superconducting state with Tc=22-24 K, accompanied by the higher residual resistivity ratios. The superconducting volume fractions are estimated from the ZFC data to be 50∼55%, indicating

Nb3Sn is an alternative material for future superconducting accelerators. With its higher critical temperature and superheating field than that of niobium, its application in the field of SRF is a great advantage. In this paper, the magnetron sputtering method is applied to prepare the Nb3Sn thin film on the oxygen-free copper substrate by the stoichiometric target—the ratio of 3:1 of niobium to tin

By self-consistently solving the Bogoliubov-de Gennes equations of a model Hamiltonian built on the honeycomb lattice, we study the roles played by the Ising spin-orbital coupling (ISOC) pertinent to the transition metal dichalcogenides (TMDs) in the presence of a magnetic field. It is shown that the presence of ISOC enables the superconductivity to survive in a high in-plane magnetic field, otherwise

The effect of Tl content in TlmBa2Can-1CunO2n+2+δ (TBCCO) superconductor was studied with m=1 and 2, n = 1-4. Samples were prepared using the standard solid-state reaction one-step technique in a sealed quartz tube under normal pressure. The superconductivity was examined using electrical resistance measurements ranging from 300 K to 10 K. The effect of an applied magnetic field (up to 12 T) on the

As research and production technologies for high-temperature superconducting (HTS) materials have become increasingly mature, many high-efficiency and low-weight electrical machines made of HTS conductors have been successfully manufactured. In this paper, a transient numerical model for processing a three-phase symmetrical short circuit in a 30-kW HTS generator is proposed. It is based on an electromagnetic

The high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle system is a kind of self-stable levitation mode, which is benefited from the characteristic of flux pinning of non-ideal type II superconductor. And this novel prototype has the outstanding advantages of simple structure, reliable principle, friendly environment and so on. But in the HTS maglev vehicle system, the damping

Superconducting fault current limiter (SFCL), which is used in voltage source converter based high voltage direct current (VSC-HVDC) transmission systems to limit fault currents and protect the grid together with DC circuit breakers, could improve system safety and stability. The first transmission voltage DC SFCL is developed in China, and it has been applied in the 160 kV VSC-HVDC transmission system

Iron-based superconductors (IBS) are considered as potential materials for manufacturing high-field magnets, for which developing multi-filamentary conductors with high performance and high strength is essential. Herein, 7-filamentary Cu/Ag composite sheathed Ba0.6K0.4Fe2As2 (Ba122) round wires and tapes were successfully prepared through the ex situ powder-in-tube (PIT) method and treated by hot isostatic

We studied the levitation of a YBa2Cu3O7 (YBCO) melt-textured superconducting specimen above a closed path of permanent magnets. The superconductor was magnetized with an auxiliary permanent magnet before brought to the path of magnets. This way, the superconducting levitation in the mixed state was achieved. The vertical and horizontal forces acting on the superconductor were calculated by means of

In order to realize practical superconducting joints between Bi2223 tapes towards persistent-current magnets, Bi2223 thick films with high critical current density (Jc) suitable for joint intermediate layers are needed. On the other hand, the methodology of c-axis grain alignment for improving the critical current properties in the polycrystalline materials with a relatively large thickness has not

We solve the two-band Ginzburg-Landau equations for a superconducting mesoscopic prism for a condensate characterized by two order parameters (ψ1,ψ2). We study the effect of the phase and γ˜ differences on the vortex state, magnetization, magnetic susceptibility (χm), vortex localization, and vorticity for boths condensate. Finally, we present shown how the vortices form conglomerates in the superconductor

In the present investigation, based on density functional theory computational approach, we show how the experimentally accepted AlB2-like structure of the SrAlGe compound is suggested to be dynamically unstable at 0 K. We propose a stable configuration that is deduced from the detailed analysis of the phonon spectrum with a doubled unit cell and buckled AlGe layers. It allows to closely reproduce

With the increase of DC transmission voltage and capacity, large dc fault current becomes an important issue due to the bottleneck of the capacity of the DC breaker. In order to solve the problem, we have proposed a novel hybrid type DC superconducting fault current limiter (DC SFCL) in our previous papers. Based on a series of previous researches, some improvements are made to design the hybrid type

From the first principles calculation based on the plane-wave pseudopotential method of density functional theory, and the linear response technique, we have performed electronic structure, phonon and electron-phonon interaction of superconducting compounds HfOs and HfRu in B2 phase. The distribution of energy with different wave vector in the first Brillouin zone and conductive charge carriers (electrons

It is generally believed that magnetization measurements on sulfur hydride under high pressure performed in 2015 [1] provided “final convincing evidence of superconductivity” [2] in that material, in agreement with theoretical predictions [3], [4]. Supported by this precedent, drops in resistance that were later observed in several other hydrides under high pressure [2, 5] have been generally accepted

Large-area high-quality MgB2 thin films were needed in many superconducting applications such as superconducting radio frequency (RF) cavities. However, fabricating large films with high quality can be difficult. Thus, a jointing method between MgB2 films can be crucial in a lot of superconducting electronic applications. In this article, we successfully fabricated superconducting joints for MgB2 films

This paper mainly focuses on the development of iron-based superconductor (IBS) coils made by a wind and react method. IBS is brittle after heat treatment, and little mechanical damage may reduce the performance of the tapes and coils. We developed a type of IBS coil with single or double pancake, which exhibits little performance reduction after some technological improvements. High-performance Ba122/Ag/AgSn

A temperature dependence of a width of ΔH=ΔB region has been studied for 5 wt.% (Fe, Ti) particle-doped MgB2 superconductor, which is the region that increased applied magnetic field is the same as increasing magnetic induction in a superconductor. The result revealed that widths of the region are linear along temperature. In this paper, we present meanings of the result and details of the calculation

Fracture of brittle filaments plays a crucial role in significant degradation of critical current density of multifilamentary Nb3Sn strand. Recent researches of distribution of filament factures mostly depend on photographic analysis with SEM or TEM. However, it is hard to obtain spatial distribution of filament fractures in the mulitifilamentary Nb3Sn strand. In addition, almost unavoidable filament

A high-temperature superconducting (HTS) axial flux permanent magnet (AFPM) machine was designed, using superconducting bulks over the rotor surface and rare-earth magnets in the middle of the stator teeth. Because of diamagnetic behavior of the HTS bulks and zero field cooling, leakage flux significantly reduces in the proposed machine compared to the existing machine with mounting rare-earth magnets

When a REBCO tape carrying DC transport current is exposed to a perpendicular AC magnetic field with amplitude above certain value, flux could be triggered to traversing the superconducting tape. During the process, a biased DC response voltage, called the dynamic resistance voltage will be induced. In the paper, the calculation on the time-dependent dynamic resistance voltage was carried out by the

A setup of transverse tension measurements of high temperature superconductor (HTS) RE-Ba-Cu-O coated conductors are modified for simplicity. Modification includes using high strength epoxy films instead of solder as adhesive agents and changing the shape of contact surface between test samples and anvils. This method was designed to measure delamination strength of stabilizer free REBCO coated conductors

A new experimental study by Snider et al. [2020 Nature 586 373–7] reported behavior in a high-pressure carbon-sulfur-hydrogen system that has been interpreted by the authors as superconductivity at room temperature. The sudden change of electrical resistance at a critical temperature and the change of the R vs. T behavior with an applied magnetic field point to superconductivity. This is a very exciting

Intermodulation distortion (IMD) of microwave signals incident upon a superconducting YBa2Cu3O7−x thin film sample on a LaAlO3 substrate is shown to relax as the sample magnetization also relaxes, revealing the signature of fluxon decay in the microwave distortion. The sample contained a microchannel of columnar defects that was introduced using heavy ion beam irradiation. After exposure to and then

A flux transformer, consisting of a superconducting primary loop (pick-up loop) in series with a superconducting secondary loop on which measurement is done, is considered to optimize the approach and sensitivity of the Superconducting QUantum Interference Device (SQUID). Performance of such a pick-up loop placed above a magnetic particle is investigated using the numerical Ginzburg-Landau (GL) simulations

Based on a fully two-dimensional (2D) electrothermal model, the quench propagation characteristics of short superconducting YBa2Cu3O7-x conductors (AMSC and SuperPower), including the minimum quench energy (MQE), normal zone propagation velocity (NZPV) and hot spot temperature rising rate, are studied by numerical simulations in this paper. It is found that different heater configurations, such as

Commercial MgB2 powder manufactured by Alfa Aesar was mechanically sieved in order to obtain powder samples with different particle size. As-sieved powders were used for single-core wires with FeNiCo sheath made by ex-situ process and heat treated at the same conditions, 950 °C/30 min. Resistive transitions of extracted MgB2 cores allowed to obtain the critical temperature and normal state resistivity

Ball milled MgB2 powders and ex situ processed tapes using those milled powders were sintered at various temperatures. Critical temperature (Tc) increases moderately with increasing sintering temperature (Tsin) up to 705 – 735 °C, at which best performance in transport critical current density (Jc) at 4.2 K in 10 T for the tape samples is obtained. In contrast, the Tc rapidly increases when sintered

High-current superconducting conductors are widely used in fusion magnets and high energy accelerators. In order to carry out experimental research on new high-current conductors, we have developed a new test facility for their critical current (Ic) measurements. We have used this facility to test a Nb-Ti Rutherford cable three times. Premature quenches were detected for the first two tests. They were

The design and testing of high current superconducting cables made of ReBa2Cu3O7-z (REBCO) are still under development. It seems to have huge potential to overcome some of the difficulties associated Low Temperature Superconductors. One of the attractive features of CORC® cable compared to other cable types is that a former with a small diameter can be used. This allows a flexible and round wire shape

In order to study the feasibility of the co-transmission of electricity and liquefied natural gas (LNG) based energy fluid, we carried out a project supported by a grant from Chinese national key research and development program, Basic Research on Superconducting DC Energy Pipeline. In this project, a superconducting cable cooled by LNG based mixed energy fluid at temperature around 90 K is proposed

Cross stiffness is usually defined as a change in the vertical force when the levitating body moves a small lateral displacement in a high-temperature superconductor (HTS) magnetic levitation system. In most of the existing research reports, the improvement of the levitation stiffness is usually focused on the radial (lateral) and axial (vertical) stiffnesses. The cross stiffness should be studied

3D integration has well-developed for traditional CMOS technology operating at room temperature, but few studies have been performed for cryogenic applications such as quantum computers. In this paper, a wafer-to-wafer bonding of superconductive joints based on niobium nitride (NbN) is performed to demonstrate the possibility of 3D integration of superconducting chips. The NbN thin films are deposited

We present a strong-coupling study of the competition and interplay between the d-density wave (DDW) and d-wave superconducting (DSC) states within the fluctuation-exchange approximation for the two-dimensional Hubbard model. We find the occurrence of a new DDW state with phase fluctuations induced by spin fluctuations above TC. It is shown that in this state the density of states has a pseudogap,

We investigated the combined effect of flux pinning by three-directional columnar defects (CDs) in a wide field-angular range of YBa2Cu3Oy thin films, where CDs parallel to the c-axis and CDs crossing at ±θi (θi = 45°, 60° and 80°) relative to the c-axis were installed by 200 MeV Xe-ion irradiations. The three-directional CDs with θi ≤ ±60° form a field angular curve of critical current density Jc

In recent years, the design of superconducting electric machines has attracted the attention of researchers and scientists due to the unique properties of high temperature superconducting materials. This paper presents a 20 kW HTS induction motor with a double squirrel cage rotor, in which the HTS and copper bars are embedded in two different slots. The propose of this paper is the investigating of