Trapped Magnetic Field of a Mini - Bulkmagnet using YBaCuO Superconductors
- PDF / 133,710 Bytes
- 5 Pages / 595 x 842 pts (A4) Page_size
- 50 Downloads / 225 Views
Trapped Magnetic Field of a Mini - Bulkmagnet using YBaCuO Superconductors
Hiroyuki Fujimoto and Hiroki Kamijo Railway Technical Research Institute, 2-8-38 Hikari-cho, Kokubunji-shi, Tokyo 185-8540, Japan. ABSTRACT We fabricated a mini-superconducting bulk magnet of 200 mm × 100 mm, consisting of 18 square bulks, 33 mm on a side and 10 mm in thickness, and magnetized the mini-magnet by field cooling. The mini-magnet showed the trapped magnetic field of larger than 0.1 T on the surface of the outer vessel of the magnet. The present preliminary study discusses the possibility of superconducting bulk magnets for the Maglev system, and trapped magnetic field properties of the mini-bulkmagnet using YBaCuO superconductors at 77K.
INTRODUCTION Enthusiastic efforts have been made to develop melt-processed YBaCuO (Y123) or Rare-earth barium-copper-oxide (RE)123 superconductors and recently NdBaCuO (Nd123) or (LRE)123 superconductors. The LRE123 superconductors have a much higher critical-current density, Jc, at 77 K and high magnetic field, leading to high field application as a superconducting quasi-permanent bulk magnet with the liquid nitrogen refrigeration. (L)REBa2Cu3O7-x bulk superconductors are being considered for a superconducting magnetic bearing, a flywheel, a motor, and high-field magnetic shielding, as well as a superconducting bulk magnet. [1-4] One of the promising applications is a superconducting magnet for the magnetically levitated (Maglev) train. [5] The magnetization of bulk superconductors with a high Jc at 77 K and a high magnetic field, and a large single domain result in a high magnetic field superconducting bulk magnet with liquid nitrogen refrigeration, of which the trapped magnetic field is superior to that of a conventional permanent magnet. [1-4] We have investigated the possibility of superconducting bulk magnets for the Maglev system. [6-12] In this study, we demonstrated a mini bulk magnet of 198 mm × 99 mm, using melt processed YBaCuO superconductors, which consists of 6 × 3 bulks, side length of 33 mm and thickness of 10 mm at 77 K.
SUPERCONDUCTING MAGLEV TRAIN The magnetically levitated (Maglev) train is a super-high-speed non-adhesive transport system with a combination of superconducting magnets (SCMs) and linear motor technology. [5] The Maglev system applies the superconducting technology of low-temperature superconductors, Nb-Ti wires, and SCMs that require liquid helium as a coolant. In addition to these well-developed technologies, high-critical temperature superconductors that show superconductivity at liquid nitrogen are also promising components for the Maglev system in the future. In Superconducting Maglev, two SCMs with on-board refrigerators are mounted on each II10.16.1
bogie of the train; each SCM consists of four superconducting coils alternately generating N poles and S poles with a pole pitch of e.g. 1.35 m. The pole size is 1 m × 0.5 m, and each pole is composed of a race-track coil made of Nb-Ti superconducting wires in a persistent current mode at 4.2 K. The persi
Data Loading...
