Thermal and Electrical Behaviour of the Persistent Current Switch for a Whole-Body Superconducting MRI Magnet
| Autor: | R. G. Sharma, Ajit Nandawadekar, Navneet Suman, Vijay Soni, R. Kumar, Sankar Ram T, Supriya Saini, Soumen Kar, Mukhtiar Singh |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
business.industry Bifilar coil Superconducting magnet Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials law.invention Conductor Inductance law Magnet 0103 physical sciences Shielded cable Optoelectronics Electrical and Electronic Engineering 010306 general physics business Electrical conductor Voltage |
| Zdroj: | IEEE Transactions on Applied Superconductivity. 31:1-5 |
| ISSN: | 2378-7074 1051-8223 |
| DOI: | 10.1109/tasc.2021.3076748 |
| Popis: | A prototype persistent current switch is developed for an actively shielded whole-body 1.5 T MRI magnet having an operating current of ∼500 A. The switch is developed using a six-strand CuNi-NbTi conductor. The total length of the conductor used in the PCS is ∼40 m using a bifilar winding technique having a room temperature resistance of 15 Ω and an inductance of 6.6 μH. Two numbers of thermo-foil heaters having a resistance of 90 Ω each are placed between the layers of the winding pack of the switch. The wet-winding technique is followed for the switch using a cryogenic grade epoxy. The characteristics of the switch are performed using a 4 K test rig for its applicability in the 1.5 T MRI magnet. The normal resistance of the switch is measured to be 12.5 Ω at 15 K which is 15% less than the estimated value. The total energy loss onto the switch is estimated to be 0.24% of the ramping energy of the magnet at 6 V charging voltage. The thermal switching profile of the switch is studied and correlated with the total energy loss. |
| Databáze: | OpenAIRE |
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