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Trapped field of 1.1T without flux jumps in an MgB2 bulk during pulsed field magnetization using a split coil with a soft iron yoke

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Fujishiro, H 
Mochizuki, H 
Ainslie, MD 
Naito, T 


MgB2 superconducting bulks have promising potential as trapped field magnets (TFMs). We have achieved a trapped field of Bz = 1.1 T on a high-Jc MgB2 bulk at 13 K without flux jumps by pulsed field magnetization (PFM) using a split-type coil with a soft iron yoke, which is a record-high trapped field by PFM for bulk MgB2 to date. The flux jumps, which frequently took place using a solenoid-type coil during PFM, were avoided by using the split-type coil, and the Bz value was enhanced by the insertion of soft iron yoke. The flux dynamics and heat generation/propagation were analyzed during PFM using a numerical simulation, in which the magnetic flux intruded and attenuated slowly in the bulk and tended to align along the axial direction due to the presence of soft iron yoke. The advantages of the split-type coil and the simultaneous use of a soft iron yoke are discussed.



pulsed field magnetization, MgB2 bulk, numerical simulation, flux jump, split-type coil, soft iron yoke

Journal Title

Superconductor Science and Technology

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IOP Publishing
Royal Academy of Engineering (RAEng) (10216/113)
Royal Society (IE131084)
Japan Society for the Promotion of Science (15K04646)
This work was supported by Open Partnership Joint Projects of Japan Society for the Promotion of Science (JSPS) Bilateral Joint Research Projects, and JSPS KAKENHI grant number 23560002 and 15K04646. Dr Mark Ainslie would like to acknowledge the support of a Royal Academy of Engineering Research Fellowship and a Royal Society International Exchanges Scheme grant, IE131084.