Junior Research Fellow (Christ's College)
MPhys University of Oxford
PhD University of Cambridge
High temperature superconductors for magnetic levitation and permanent magnets
My research work with the Applied Superconductivity and Cryoscience Group focuses on the electromagnetic behaviour of high temperature superconducting (HTS) tape for rotating machine applications. HTS tape can carry large persistent currents and when many layers are stacked together, they can be magnetized to act as powerful permanent magnets generating many tesla. This is despite the fact that they have only a few percent superconductor by volume fraction. They serve as a very compact source of high magnetic field which is useful for motor and generator applications requiring very high power density and efficiency. One of the biggest challenges is how you magnetize them at cryogenic temperatures. My research focusses on experiments and FEM modelling of electromagnetic behaviour of the HTS composite stacks when magnetised by a pulsed field. The effect of the material properties on the ‘trapped field’ of the magnets is not fully known as well as how best to minimise any demagnetizing effects. The thermal and mechanical stability of the HTS tape stacks along with their flexible shape are key advantages for applications.
These HTS tape stacks can also be used as the passive component of magnetic bearings. Work supported by SKF has investigated the levitation force properties of a rare-earth PM – HTS tape stack systems. The research shows that similar forces can be generated by the stacks compared to HTS bulks of equivalent size and shape.
Selection of HTS tape stacks created by the Applied Superconductivity and Cryoscience Group and collaborators.
- A. Patel, S. C. Hopkins, A. Baskys, V. Kalitka, A. Molodyk, and B. A. Glowacki, "Magnetic levitation using high temperature superconducting pancake coils as composite bulk cylinders" Superconductor Science and Technology, 28 (2015) 115007
- A. Patel, A. Baskys, S. C. Hopkins, V. Kalitka, A. Molodyk, and B. A. Glowacki, "Pulsed-Field Magnetization of Superconducting Tape Stacks for Motor Applications" IEEE Transactions on Applied Superconductivity, 25 (2015) 5203405
- A. Patel, K. Filar, V. I. Nizhankovskii, S. C. Hopkins, and B. A. Glowacki, "Trapped fields greater than 7 T in a 12 mm square stack of commercial high-temperature superconducting tape" Applied Physics Letters, 102 (2013) 102601-5
- A. Patel, S. C. Hopkins, and B. A. Glowacki, "Trapped fields up to 2 T in a 12 mm square stack of commercial superconducting tape using pulsed field magnetization" Superconductor Science and Technology (Fast Track Communication), 26 (2013) 032001
- A. Patel and B. A. Glowacki, "Enhanced trapped field achieved in a superconducting bulk using high thermal conductivity structures following simulated pulsed field magnetization" Superconductor Science and Technology, 25 (2012) 125015