Improvement of YBCO Superconductor Magnetic Shielding by Using Multiple Bulks

Douine, Bruno; Male, G.; Lubin, Thierry; Mezani, Smaïl; Lévêque, Jean; Berger, Kévin

doi:10.1007/s10948-013-2460-5

Cited by 12 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This kind of numerical problem can be time consuming when dealing with the superconducting behavior [14]. Numerical methods, as Finite Element [8] or other methods described in [9], are however essential to calculate accurately the induced current inside the pellets and so the magnetic behavior of the superconducting inductor. For these methods, the variation in the resistivity of superconductors is given by a power law.…”

Section: Electromagnetic Designmentioning

confidence: 99%

Design of a superconducting machine and its cooling system for an aeronautics application

Colle

Lubin

Lévêque

2021

Eur. Phys. J. Appl. Phys.

View full text Add to dashboard Cite

The transition to electric propulsion aircraft requires electrical motors or generators with high power density. The “zero resistivity” of the superconducting materials could be used in electrical machines to produce high magnetic fields and reduce the use of heavy components such as the ferromagnetic parts. The discovery and recent developments in High Temperature Superconductors (HTS) technology make the superconducting machine a serious candidate in the future of aircraft. The design of a superconducting machine is strongly dependent on its electromagnetic and thermal behavior. In this paper, the design of a 50 kW superconducting aircraft generator is presented. The mass of the cryogenic cooling system is included into the design in order to optimize the entire superconducting system. The study shows that the optimal temperature which conduct to the lighter superconducting system depends on the power of the superconducting machine.

show abstract

Section: Electromagnetic Designmentioning

confidence: 99%

Design of a superconducting machine and its cooling system for an aeronautics application

Colle

Lubin

Lévêque

2021

Eur. Phys. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…3) were found to be: B 00 = 2.67 T, δ = 1.54, β = 2.56, J c00 = J c0 (T ref ) = 109 A/mm 2 with T ref = 77 K and γ = 0.96. To get a sense of the viability of the chosen model, Fig 2 compares the proposed current density model with experimental data published in [30], [31] for a YBCO bulk having J c 350 A/cm 2 at B 0 T and 77 K against values currently obtained at the authors' university laboratory in the range of 100-200 A/cm 2 [10], [32]. The former data corresponds to a magnetic flux density applied along the c-axis.…”

Section: Modified Kim-anderson Relationmentioning

confidence: 99%

Comparison Between Modeling and Experimental Results of Magnetic Flux Trapped in YBCO Bulks

Trillaud

Berger

Douine

et al. 2016

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

An electromagnetic simulation of YBCO bulks was performed and the resulting trapped magnetic flux density was compared to Field Cooling experimental measurements for an applied magnetic flux density up to 3 T. The simulation relied on an axisymmetric problem implementing an A-formulation of the Maxwell's equations solved by means of the Finite Element Method so that the time evolution of the magnetic flux density was computed over the cross section of the bulk. To derive its electrical conductivity, a classic power law was adopted that includes the dependence of the critical current density upon temperature and external magnetic field modelled on the basis of a Modified Kim-Anderson relation. It was found that this model tends asymptotically towards the critical state for which the n-value becomes a free parameter that should be then estimated experimentally. The experimental results could be fairly reproduced at different operating temperatures with the best trapping at temperatures below 77 K benefiting from an increasing critical current density. Index Terms-Modified Kim-Anderson relation, trapped magnetic flux, YBCO bulk modelling.

show abstract

“…One possible solution is to arrange side-by-side several bulks. Such a topology may require several layers of bulks in a brick-wall arrangement to mitigate the presence of gaps between them [18,[31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Improving the screening ability of high-temperature superconductors by combining disk-shaped bulks and closed-loop coated conductors

Rotheudt,

Brialmont,

Fagnard

et al. 2024

Supercond. Sci. Technol.

View full text Add to dashboard Cite

In this work, we demonstrate experimentally the remarkable DC magnetic screening ability of hybrid superconducting screens. The configurations under investigation combine a 30 mm-diameter disk-shaped superconducting bulk, or another with a 10 mm-diameter hole, with different closed superconducting loops made from coated conductors. The loops are placed coaxially with the bulk. The bulk superconductors and the closed-loop coated conductors are made of GdBa2Cu3O7 and the experiments are performed in liquid nitrogen (77 K). The DC and inhomogeneous field to be screened is produced by a bespoke coil and reaches around 100 mT at the location of the superconducting bulk, which is much less than its full-penetration field. By mapping the magnitude of the flux density using a 3-axis cryogenic Hall probe, we show that such a hybrid superconducting screen allows the maximum shielding factor SF above the bulk to be almost doubled. For the best investigated hybrid configuration, the SF reaches ~45 at 2.7 mm above the bulk. In addition, the area of the spatial region for which less than half of the applied field remains (SF > 2) is roughly multiplied by 4 when compared to a situation involving only a disk-shaped bulk. In this work, this region corresponds to a 60 mm-diameter circle. The choice of the loop diameter is found to result from a trade-off between maximum SF and extension of the screened region. Finally, we detail why these hybrid configurations bring such improvements: the key point is that the flux lines generated by the source coil are diverted by the bulk towards a region where the closed-loop coated conductors can oppose the best to them.

show abstract

Improvement of YBCO Superconductor Magnetic Shielding by Using Multiple Bulks

Cited by 12 publications

References 8 publications

Design of a superconducting machine and its cooling system for an aeronautics application

Design of a superconducting machine and its cooling system for an aeronautics application

Comparison Between Modeling and Experimental Results of Magnetic Flux Trapped in YBCO Bulks

Improving the screening ability of high-temperature superconductors by combining disk-shaped bulks and closed-loop coated conductors

Contact Info

Product

Resources

About