Optimization of Thermal Material in a Flux Pump System With High Temperature Superconductor

Superconductors are known for the ability to trap magnetic field. A thermally actuated magnetization (TAM) flux pump is a system that utilizes the thermal material to generate multiple small magnetic pulses resulting in a high magnetization accumulated in the superconductor. Ferrites are a good thermal material candidate for the future TAM flux pumps because the relative permeability of ferrite changes significantly with temperature, particularly around the Curie temperature. Several soft ferrites have been specially synthesized to reduce the cost and improve the efficiency of the TAM flux pump. Various ferrite com- positions have been tested under a temperature variation ranging from 77K to 300K. The experimental results of the synthesized soft ferrites-Cu_0.3Zn_0.7Ti_0.04Fe_1.96O₄, including the Curie temperature, magnetic relative permeability and the volume magnetization (emu/cm³), are presented in this paper. The results are compared with original thermal material, gadolinium, used in the TAM flux pump system. Cu_0.3Zn_0.7Ti_0.04Fe_1.96O₄ holds superior characteristics and is believed to be a suitable material for next generation TAM flux pump.