Development of a Liquid Hydrogen Transfer Pump System with MgB2 Wires*1

Abstract

An electric pump composed of an MgB2 motor is combined with superconducting level sensors using thin CuNi-sheathed MgB2 wires to transfer liquid hydrogen. An impeller is attached to the lower end of a rotating shaft on the MgB2 motor and covered with an outer casing to form a centrifugal pump. Then, the MgB2 motor and impeller are placed vertically inside a cryostat with an infill of liquid hydrogen. A glass Dewar vessel is prepared to receive the liquid hydrogen transferred from the cryostat containing the MgB2 motor. The MgB2 sensors are used not only to detect the level of liquid hydrogen but also to control the electric pump on the basis of their pre-estimated calibration curves. By using the assembled pump system, the liquid hydrogen is successfully transferred from the cryostat to the glass Dewar vessel via a transfer tube. / 21Highlights: A pump system composed of an MgB 2 motor and MgB 2 level sensors was constructed. The centrifugal pump was formed by attaching an aluminum impeller to the motor. A glass Dewar vessel receives the liquid hydrogen from a cryostat for the pump. The MgB 2 sensors were used to detect the liquid level and to control the motor. Transfer of liquid hydrogen was successfully carried out with the pump system. liquid hydrogen but also to control the electric pump on the basis of their pre-estimated calibration curves. By using the assembled pump system, the liquid hydrogen is successfully transferred from the cryostat to the glass Dewar vessel via a transfer tube.