Development of a Desktop-Type Superconducting Bulk Magnet

Trapped field potential of commercial Y-Ba-Cu-O bulk superconductors designed for applications

“…However, practically, magnetic fields generated at the surface of bulk HTSs at temperatures that can be obtained with off-the-shelf cryocoolers are more valuable for bulk HTS compact magnetic systems, which can be used for magnetic separation [40], Maglev transportation [7], magnetic bearing [7][8][9]41], electrical rotary machines [12], Lorentz Force Velocimetry [42], and portable bulk HTS magnets [43][44][45][46]. The highest surface trapped field performance, i.e.…”

“…Nevertheless, the practical use of bulk HTSs with several-Tesla trapped fields was realized in magnetic-force-based applications. Currently, such bulk-HTS-based devices continue to be developed as a holistic engineering solution addressing equipment miniaturization, adopting commercial cryocooler technology [43,45,46], and deploying compact pulse magnetization [53][54][55]. However, the primary issues related to the commercial use of the bulk HTS technology are established on the enhancement of trapped magnetic fields, as well as their reliability and reproducibility at temperatures achievable with off-the-shelf cryocoolers.…”

Bulk superconductors: a roadmap to applications

“…Major challenges Large diameter samples with high, homogeneous J c characteristics. A large B and field gradient are needed for many of the medical applications described above, which leads to a requirement of a high and homogeneous critical current density, J c , flowing near-uniformly over the volume of Photograph and schematic of the desktop-type superconducting bulk magnet system developed by Yokoyama et al [30]. © 2016 IEEE.…”

“…To develop a more commercially attractive device, a faster, more compact and less complicated magnetisation system is required, which leads naturally leads to PFM, where a large, pulsed magnetic field on the order of milliseconds is applied to a bulk by discharging the energy stored in a capacitor bank through a copper magnetising coil(s). There have been some recent investigations on using PFM to magnetise portable bulk superconductor magnet systems: >3 T has been achieved by Zhou et al at 51 K using a 30 mm diameter bulk Gd-Ba-Cu-O superconductor, cooled using a portable Stirling cycle cryocooler (Cryotel CT, Sunpower) and magnetised by a multi-pulse, multi-temperature PFM technique exploiting flux jumps (see figure 3) [9]; 2.8 T at 52.3 K using a 45 mm diameter Gd-Ba-Cu-O bulk [30] and 3 T at 55.6 K using a 60 mm diameter bulk [31] has been achieved by Yokoyama et al using the same type of cryocooler, but magnetised by single-pulse PFM (see figure 4).…”

“…Figure 4.Photograph and schematic of the desktop-type superconducting bulk magnet system developed by Yokoyama et al[30]. © 2016 IEEE.…”