Presentation Information
[WBP2-11]Simplification of magnetization procedure using a new FAVS (First Applying a Very Small magnetic field) method for pulsed-field magnetization
*Kazuya Yokoyama1, Kaoru Ishibashi1, Tetsuo Oka2 (1. Ashikaga University (Japan), 2. Shibaura Institute of Technology (Japan))
Keywords:
REBCO bulk,pulsed-field magnetization,heat generation,flux penetration,magnetic flux trapping
Superconducting bulk magnets can generate higher magnetic fields than can permanent magnets or electromagnets in a compact and lightweight device. In industrial applications of superconducting bulk magnets, pulsed-field magnetization (PFM) is an effective method because it can magnetize the bulk on site in a short time, but improving the trapped field and simplifying the magnetization procedure remain challenges. This paper proposes a new PFM technique that adds a new method—FAVS (First Applying a Very Small magnetic field)—immediately before the application of a pulsed field of the desired magnitude. The aim is to form a magnetic flux path by slightly heating the low-characteristic part of the sample with the first application, and then applying the second magnetic field before the temperature of that part drops (the magnetic flux path closes), thereby efficiently introducing magnetic flux into that part. Since the temperature rise of the entire sample can be suppressed, improvement of the trapped field can be expected. In addition, the proposed method has the advantage of being able to magnetize with only a simple change in procedure without changing the device. To confirm the principle and effectiveness of the proposed method, PFM experiments were conducted using a φ60 × t20 mm GdBCO bulk, varying the magnitude of the first applied field from 0.8 to 3.1 T and fixing the second applied field at 5.0 T. When the first applied field was 0.8 to 1.9 T, the trapped field improved by up to 13.6% compared to when a single pulse of 5.0 T was applied, demonstrating the effectiveness of the proposed FAVS method.