A novel application concept of high-temperature superconducting cable for seabed coils in ship magnetic deperming

Navies have been performing naval ship deperming since World War II. Deperming requires an estimated magnetic field of a few milli-tesla, which is middle in intensity as an artificially generated field. However, the volume required for this magnetic field is as large as the involved ship volume. A concept of flat coil comprising a high-temperature superconducting cable, set on the seabed in shallow water, is expected to have an effective deperming system of a ship. This system requires a magnetic field to overcome the vertical demagnetization of the ship, which is higher than the longitudinal factor. To incorporate a superconducting good performance, we design a coil comprising a present superconductor cooled through liquid hydrogen circulation. Starting from the estimation of the required magnetic field, the cable with 200 kA passing and 1200 m length is discussed, along with the consideration of the liquid hydrogen cooling and required power source for deperming.