Numerical optimization of monofilamentary MgB2 wires with different metal sheath materials for liquid hydrogen level sensor

Abstract

Thin wires required for a new type of superconducting level sensors are investigated in some virtual situations. The sensors are composed of an MgB 2 wire with metal sheath and a non-superconducting wire, which are located in parallel and connected in series, to determine a level of liquid hydrogen in a container with higher reliability. The operations of the level sensors during refill and discharge of liquid hydrogen are simulated numerically by solving a onedimensional heat balance equation. The wires have a metal material with almost constant dependence of resistivity on temperature such as cupronickel or stainless steel. The wire lengths are assumed to be 1 meter. By using the obtained numerical results, the optimum compositions of the MgB 2 and non-superconducting wires are discussed for several parameters such as materials and volume fractions of metal sheaths, temperatures of pressurized liquid hydrogen, and conditions of evaporated gas.