Very strong levitation force and stability achieved with a large MgB₂ superconductor disc

Abstract

This rapid communication highlights a remarkable achievement obtained with a 120 mm diameter large cylindrical MgB2 bulk: the measurement of magnetic levitation forces up to 700 N at 20 K, levitation being stable up to levitation forces exceeding 400 N. The investigated sample, which has one of the largest dimensions reported in the literature, was fabricated using the unconventional Spark Plasma Sintering technique. This method is known as one of the most efficient methods for producing dense MgB2 samples [1–3]. This breakthrough holds significant potential for advancing high-performance levitation systems and superconducting applications, including high-speed transportation systems and magnetic bearings.

Estimation of magnetic levitation and lateral forces in MgB2 superconducting bulks with various dimensional sizes using artificial intelligence techniques

“…These motors are situated outside the vacuum chamber and are linked to the PM through a rod passing through a vacuum-tight flexible steel tube. The maximum excursion of the PM along the vertical and the horizontal direction is 55.9 mm, whereas levitation forces up to 700 N were recently measured in this facility [8]. The copper cold plate is linked to the second stage of the Sumitomo Cryocooler RDK 415D, potentially capable of cooling the plate down to 4.2 K with a cooling power of 1.5 W at the same temperature.…”

“…The stability of such systems is closely related to the ratio of dimensions between the superconducting materials and the magnet source, the cooling distance, and the working temperature. A highly stable levitation force exceeding 400 N was achieved using a 120 mm diameter MgB 2 bulk fabricated within 2 h [8]. This value is comparable to systems consisting of ReBCO bulks [10], and the fabrication process for superconducting samples is much faster and simpler.…”

“…This study utilized ten cylindrical bulks of MgB 2 , prepared through the SPS technology [8] using MgB 2 powder acquired from Pavazyum company (in Turkey). SPS is renowned for its efficiency in producing highly dense MgB 2 bulks by applying uniaxial pressure and simultaneously high-intensity current to heat and densify the pellets [26,27].…”

“…These include magnetic field shielding, motors/generators, NMR/MRI, magnetic bearings, flywheel energy storage, and Maglev trains utilizing superconducting magnetic levitation (SML) systems [1][2][3]. While ReBCO bulk has received more attention for its superior superconducting properties and cost-effective cooling method in these applications, advancements in high-quality and largesize MgB 2 bulk fabrication [4][5][6] and two letters recently published in the "Superconductor Science and Technology" journal [7,8] have unveiled the significant potential of MgB 2 bulk material for new applications such as SML and NMR systems utilizing hydrogen liquid cooling. This also presents a promising avenue for clean energy development [9].…”