Stability margin of a high-temperature superconducting (HTS) coil is two or three orders magnitude greater than that low-temperature coil. In recent years, many papers have reported test results turn-to-turn no-insulation (NI) HTS coils having extremely enhanced thermal stability, such burnout never occurs in an NI coil, even at operating current exceeding 2.5 times the critical current. Thus, The main goal this paper to clarify transient electromagnetic and behaviors mechanism high...

Surface and subsurface oxygen vacancies on the slightly reduced ${\mathrm{CeO}}_{2}(111)$ surface have been studied by atomic resolution dynamic force microscopy at 80 K. Both types of defect are clearly identified comparison observed topographic features with corresponding structures predicted from recent first-principles calculations. By combining two simultaneously acquired signals (the topography energy dissipated cantilever oscillation), we able to unambiguously locate buried third...

In a REBCO superconducting magnet for magnetic resonance imaging (MRI) applications, the large screening current induced by field perpendicular to winding tape is serious problem: it generates irregular that deteriorates spatial homogeneity and temporal stability in MRI applications. Therefore, we need estimate generated using electromagnetic analysis design develop highly accurate stable field. examine influence of current, constructed cryocooler-cooled small bore-coil stacked pancake coils...

Recently, no-insulation (NI) winding techniques have been proposed for achieving high current density and thermal stability. To verify the excellent characteristics achieved using these techniques, we investigated transient behaviors of NI REBCO pancake coils. In this paper, evaluate electromagnetic during a local normal-state transition, based on partial element equivalent circuit coupled numerical analysis. Moreover, investigate temporal spatial distributions in coil after normal...

In coils wound with high-temperature superconducting (HTS) tapes, large screening currents are induced in the tape by radial component of magnetic field. Furthermore, when a transport current is supplied to HTS under field, total (which consists and currents) flows inhomogeneously. The field generated affects distribution cyclotron applications. Investigating effects on reduction, hysteresis, drift coil therefore necessary. our previous studies, we have developed novel simulation code for...

In recent years, the quality of high-temperature superconducting (HTS) tapes has been improving rapidly, becoming available in sufficient quantity and length, can be applied to devices for power systems industrial applications. Therefore, we are carrying out a feasibility study on application HTS coil medical accelerator system particle cancer therapy, designing new cyclotron that is compact, highly efficient, able extract high-energy beam consume less power. this paper, report our effort...

A project on the development of REBa2Cu3O7−δ (REBCO) magnets for ultra-high-field magnetic resonance imaging (MRI) was started in 2013. Since REBCO-coated conductors feature high mechanical strength under tensile stress and critical current density, use REBCO coils would allow superconducting to be made smaller lighter than conventional ones. In addition, a conduction-cooled magnet is simpler one cooled by liquid helium bath because operation maintenance cryogenic system become simpler,...

An R&D project on high-temperature superconducting (HTS) magnets using (RE)Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> (REBCO; <inline-formula xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{RE}=\text{rare earth}$</tex-math></inline-formula> ) wires for ultrahigh-field (UHF) magnetic resonance...

This paper presents analytical studies on the charging characteristics of a no-insulation (NI) REBCO pancake coil. A partial element equivalent circuit (PEEC) model has been developed to evaluate local current paths in NI coils. The PEEC is able consider asymmetry coil winding, turn-to-turn contact electrical resistance, and self mutual inductances. analysis results are compared with previous experimental simulations using simplified parallel (SPEC) validate proposed approach model. To...

We have been developing a no-insulation (NI) winding technique to be used in both high thermal stability and current density, which tradeoff relationship. This paper presents numerical experimental studies on the of an NI REBCO pancake coil by focusing quench protection scheme. In case accident or local normal-state transition, power supply for superconducting must immediately shut down order ensure its safety. During sudden discharging conventional insulated coil, most stored...

YBCO tape is expected to be used in future HTS applications, because it has better J/sub c/ characteristic high temperatures and applied magnetic fields. It important consider the stability superconducting applications. To establish criterion for coated conductors, characteristics of transition normal state normal-zone propagation sample tapes were examined experimentally numerically. The produced by IBAD/PLD method. Measurements performed as a function both heat input operating current 55...

We intend to develop and obtain a compact, high-efficiency high-performance cyclotron using the high-temperature superconducting (HTS) magnet technology. In applications, high-accuracy magnetic field distribution with an isochronous azimuthally varying is spatially temporally required for HTS coil. coils wound tapes, large shielding currents are induced in tape by radial component of field. The generated current affects application following issues: (1) reduction current, (2) accuracy...

High strength against electromagnetic force is required for high magnetic field and large capacity coil in order to develop large-capacity superconducting energy storage (SMES) systems electric power system control. Also, suppression of delaminating Yttrium (Y) based coated conductor a manufacture the highly reliable durable coil. Insulating coating, using liquid resin low-temperature-curable-polyamide, was developed showed durability at very low temperature without deterioration transport...

We have been developing no-insulation (NI) REBCO coil system for its application in superconducting magnetic energy storage (SMES). SMES has the advantages of high efficiency, long life, and ability to respond large amounts power instantaneously. However, an extremely low density. To address this issue, use NI-REBCO coils, designed achieve both thermal stability current density, is expected enable realization density SMES. In addition, since a device, inductance design desired. Therefore, we...

The magnet technology of a high-temperature superconductor (HTS) with conduction cooling system by GM cryocooler has been advanced. It is very important to understand the thermal and electromagnetic phenomena in HTS tapes for coil design. We have measured quench characteristics developed computer program based on finite element method (FEM) investigate behaviors within tapes. From these experimental analytical results, validity confirmed. In this paper, we discuss stability criterion...

A Japanese national project called "Materials & Power Applications of Coated Conductors (M-PACC)" started in FY2008. In this project, we are developing a 66 kV/5 kA large-current high-temperature superconducting (HTS) cable and 275 kV/3 high-voltage HTS cable, using rare-earth barium copper oxide (REBCO) tapes. These cables expected to offer compact with large capacity low power transmission loss. After the design has been studied elemental technologies for each component system, such as ac...

This paper presents the thermal and electromagnetic behaviors of multistacked no-insulation (NI) REBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">7-x</sub> (REBCO, RE = rare earth) pancake coils. The NI winding technique gives a high enough stability not to damage REBCO coils even though normal-state transition occurs. has been verified...

The development of NMR/MRI REBa2Cu3O y (REBCO, RE = rare earth) magnets is happening all over the world. It has been found that screening current-induced magnetic fields (SCMFs) are a serious problem for wound with REBCO tapes. reduction SCMFs strongly desired, and estimation also desired at design stage magnets. In order to evaluate SCMF, finite element method (FEM) or boundary integration needed thus far, high-level simulation technique required. this paper, we develop an easy estimate...

In autumn 2017, the project "Quantum Innovation for Safe and Smart Society (QiSS)" was started in Program on Open Platform with Enterprises, Research Institute Academia (OPERA) by Japan Science Technology Agency (JST). One of key issues this is advancement compact cyclotron beam irradiation device stable supply short-lived radioisotope (RI). We proposed air-core using high-temperature superconducting (HTS) technology, named Skeleton Cyclotron, as high intensity cyclotron. Currently, we are...

The purpose of this study is to propose a criterion for determining stabilizer thickness YBCO coated conductors. permissible disturbance energy density in high-temperature superconductors (HTSs) two or three orders magnitude greater than that low-temperature (LTSs). On the other hand, enhance reliability and safety HTS coils, an establishment protection scheme assuming quench caused by failure power supply, cooling system similar problem also required coil systems. Quenching produces...

We have constructed and demonstrated levitating transporter models composed of the superconductor bulks (HTS bulks) permanent magnets. The dynamic characteristics lift force, lateral force magnetic stiffness are very important for design superconducting devices such as a levitation system. electromagnetic phenomenon should be clarified through accurate analyses field shielding current distributions within HTS bulks. In this study, we developed new simulation program based on...