ICEC/ICMC 2014 Conference

Trapped Field Properties of Ring-shaped Bulk Annuli for NMR Application

10 Jul 2014, 10:30

2h 15m

Poster presentation (105min) M-06: HTS Bulk Thu-Mo-Posters Session 3.5

Speaker

Masaru Tomita (Railway Technical Research Institute)

Description

Rare-earth barium-copper-oxide (REBCO) bulk superconductors with Tc > 90 K have high critical current density (Jc) under up to high magnetic fields, so that REBCO bulks have potential to generate a strong magnetic field in compact size. In the present study, we fabricated ring-shaped bulk annuli and evaluated trapped field property for NMR application. The disk-shaped bulks were processed into ring-shaped bulks with an inner diameter of 45 mm, an outer diameter of 80 mm and a thickness of 15 mm, and reinforced with metal ring and epoxy resin. These bulks were cooled by liquid Nitrogen or a cryocooler under an external field of up to 8 T and were magnetized in field-cooling condition. The trapped field properties were evaluated by a cryogenic Hall probe. In liquid Nitrogen, the trapped field of the center of a bulk equivalent to the empty core of a bulk was 0.74 T and the difference within the compass of 6 mm in radial direction was less than 5%. Furthermore, the trapped field value of the center of ten layered bulks was over 2.5 T. The results of the bulks cooled by a cryocooler will be discussed. Acknowledgement This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science under grant No. 24300185.