Recently, we developed a 0.5-T/300 mm MgB2 magnet using the partial insulation (PI) winding technique that only employs layer-to-layer insulations without the turn-to-turn insulations; the magnet was self-protective but has a significant charge–discharge delay. In this study, the use of Cr-coated MgB2 wires was proposed as an alternative solution to enhance the characteristic resistance of the MgB2 magnet, in combination with the PI winding technique. The charging–discharging tests confirmed that the charging–discharging rates of the PI magnet that uses Cr-coated wires was ten times faster than the magnet that utilizes uncoated wires. In addition, the self-protective behavior of the PI magnet that uses the Cr-coated wires were verified via the over-current tests. Herein, the feasibility of employing the proposed winding technique for the development of self-protective MgB2 magnetic resonance imaging magnets with fast charging–discharging rates was discussed in detail.
This work was supported by the Materials and Components Technology Development Program of KEIT [10053590, Development of MgB2 wire and coil with a high critical current and long length for superconducting medical·electric power equipment].