Mechanical Damage Protection Method by Reducing Induced Current in NI REBCO Pancake Coils During Quench Propagation

Mato, Takanobu; Hahn, Seungyong; Noguchi, So

doi:10.1109/tasc.2021.3065879

Cited by 6 publications

(3 citation statements)

References 23 publications

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“…For instance, Little Big Coil 3 (LBC3) showed that an HTS magnet could generate 14.4 T under a high field environment of 31.1 T with 1420 Amm −2 of operating current density [10]. On the other hand, in order to use HTS magnets for accelerator applications, the issues on the screeningcurrent-induced-stress [11][12][13][14][15] and overstrain occurred during quench [16][17][18][19] need to be investigated further. Hence, the HTS magnet is not an effective option in low magnetic fields and there also remain issues, but it can be considered as an essential choice in the high-field region.…”

Section: Introductionmentioning

confidence: 99%

Investigation on nonuniform current density and shape deformation affecting the magnetic field performance of a saddle-shaped no-insulation HTS cosine–theta dipole magnet

Kim

Park

Bang

et al. 2023

Supercond. Sci. Technol.

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In particle accelerators, high magnetic fields are desirable for discovering new particles. Dipole magnets using superconductors have played a key role in creating required field intensity and uniformity. In contrast, high temperature superconductor (HTS) dipole magnets have recently been spotlighted because of their ability to generate higher magnetic fields compared to their low temperature superconductor counterpart. Similar needs have emerged in other fields using magnets, and no-insulation (NI) technology is considered a feasible option to reach high magnetic fields by overcoming the disadvantages of HTS magnets. However, research has rarely been carried out on the utilization of NI HTS magnet technology for dipole magnets in high-field accelerators. Here we show the design, fabrication, and test results of an NI HTS dipole magnet with numerical analysis results. This paper aims to investigate the effect of nonuniform current density and undesirable shape deformation on the magnetic field distribution of a saddle-shaped NI HTS dipole magnet. The magnet is designed and constructed considering the 'constant perimeter winding' technique and tested in liquid nitrogen. The field mapping process is also performed along a designated mapping trajectory to obtain a magnetic field distribution. T-A formulation-based simulation model, named 'sequential simulation model,' is suggested to reproduce measurements and employed considering current distribution and shape deformation. As a result of quantitative analysis of the transverse direction measurement results, the magnetic field error decreased by 0.02 percent point (pp) when the nonuniform current density is considered. It decreased by 0.13 pp when the shape deformation is considered. Moreover, the critical current calculated through additional numerical analysis shows an error of up to 10%. In conclusion, the saddle-shaped NI HTS dipole magnet can produce a sufficient magnetic field level for particle accelerator research, even though the field distribution shows a uniformity of 0.37% within this study.

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Section: Introductionmentioning

confidence: 99%

Investigation on nonuniform current density and shape deformation affecting the magnetic field performance of a saddle-shaped no-insulation HTS cosine–theta dipole magnet

Kim

Park

Bang

et al. 2023

Supercond. Sci. Technol.

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“…In our magnet, the MS consists of REBCO NI turns implemented in the middle of the stainless steel (SS) OB. An and Mato [21,22] have numerically shown in 2020 and 2021 the beneficial effect of such technology in the peak temperature and stresses during quenches of an NI magnet. We can confirm it with our magnet built in 2018, which handled a sudden discharge of the outsert (and of itself) at very high field (above 28 T), and a quench at 32.5 T, without mechanical breaking of the winding.…”

Section: Introductionmentioning

confidence: 99%

Metal-as-insulation HTS coils

Lécrevisse¹,

Chaud

Fazilleau³

et al. 2022

Supercond. Sci. Technol.

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In this article, we summarize what we have learned about Metal-as-Insulation (MI) winding behavior and technical challenges. Bailey et al. first proposed the use of Metallic Insulation (MI) for superconducting magnet in 1988 through a U.S. patent. High Temperature Superconductor (HTS) materials are highly thermally stable. This feature compared to classical Low Temperature Superconductor (LTS) enables the use of MI technology to improve the protection against quenches. Gupta was the first to propose the use of a metallic tape in an HTS winding to avoid too much radial currents in No Insulation (NI) in 2011. Hahn et al. presented preliminary results on a pancake sample the same year. We are proposing here to come back on the work done for about 10 years by research groups worldwide and will focus on the turn-to-turn contact resistivity Rct parameter. We will also give details of our LNCMI-CEA-Néel Institute MI HTS insert built in 2018 in the framework of the French National Research Agency (ANR) funding through the NOUGAT project. We tested this magnet many times between 2018 and 2021 and learnt a lot on this technology. This magnet is the first REBCO solenoid of this size using this technology and tested intensively at such high magnetic field (up to 32.5 T) so far. In this magnet, we firstly include a magnetic shielding technology consisting of REBCO NI turns inside the overbanding of each pancake. We give some details and effect of such technology inside an HTS MI insert in case of a fast discharge, a quench or an outsert failure. Finally, we discuss about the self-protection feature of MI coils and we propose a passive protection way for high Rct values.

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“…A similar phenomenon would happen in REBCO windings. Although several methods for the mechanical stability improvements were proposed [9], [10], it is necessary to clarify the mechanical phenomenon of both REBCO tapes and windings towards further developments of ultra-high magnetic field magnets.…”

Section: Introductionmentioning

confidence: 99%

Plastic Deformation Simulation of REBCO Tapes Using Particle Methods

Mato

Noguchi

2022

IEEE Trans. Appl. Supercond.

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Ultra-high field superconducting magnets are facing a mechanical degradation problem. On 2017, a world-record high DC magnetic field of 45.5 T was generated by insert no-insulation (NI) Rare-Earth Barium Copper Oxide (REBCO) pancake coils (14.4 T), called "LBC3", and an outsert resistive magnet (31.1 T). Although the experiment showed a high potential of the NI REBCO magnets for ultra-high field generation, the insert NI REBCO pancake coils and the REBCO tapes were plastically deformed. The critical current properties of damaged REBCO tapes were degraded although the Hastelloy substrate of REBCO tapes is stiff and it has a high yield point of approximately 1 GPa. However, the mechanisms of the damaging REBCO tapes are not clarified. Therefore, it is necessary to clarify the mechanical phenomenon of REBCO tapes.In this paper, we model a REBCO tape with a smoothed particle hydrodynamics (SPH) method, which can represent plastic deformation. The SPH simulation is coupled with electromagnetic analysis with a partial element equivalent circuit (PEEC) model which we have previously developed. In the simulation, an external field, which linearly increases to 5 T and then decreases to 0 T, is applied to a short-length REBCO tape. The simulation results show that the REBCO tape largely deforms during the external field excitation and deexcitation.

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Mechanical Damage Protection Method by Reducing Induced Current in NI REBCO Pancake Coils During Quench Propagation

Cited by 6 publications

References 23 publications

Investigation on nonuniform current density and shape deformation affecting the magnetic field performance of a saddle-shaped no-insulation HTS cosine–theta dipole magnet

Investigation on nonuniform current density and shape deformation affecting the magnetic field performance of a saddle-shaped no-insulation HTS cosine–theta dipole magnet

Metal-as-insulation HTS coils

Plastic Deformation Simulation of REBCO Tapes Using Particle Methods

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