Development Of A Multi-point Magnetic Field And Temperature Real-time Measuring Device For Superconductor Surfaces

The high temperature superconducting technology has been paid more and more attention by countries with the development of science and technology.In particular,the developed countries have invested much manpower and material resource in the research of superconductivity,They expect to make a breakthrough to lead the international position in the study of superconductivity.The single domain RE-Ba-Cu-O(referred to as REBCO,RE for rare earth elements:Nd,Y,Gd and Sm)superconductors have the widely and potential applications in the high-tech fields,such as superconducting magnet,superconductor maglev and flywheels,etc because of the self stabilized magnetic levitation characteristics,the higher critical current density,the high trapping magnetic flux and the large magnetic levitation force.One of the most important parameters to judge the performance of REBCO superconductor is the trapped field.However,the trapped field of REBCO superconductor is not only related to its own characteristics,but also the ways of magnetization,which is closely related to the magnetization mechanism of the sample under different magnetization conditions.Therefore,it is a very valuable research subject to measure the changes of physical properties of the superconductor in the process of magnetization.In order to investigate the mechanism and the magnetization pattern better,and further enhance the trapped field under the different conditions,this paper is based on the measurement of the axial magnetic field and temperature distribution in the process of superconductor magnetization,we have studied and developed a new device to measure the temperature distribution and magnetic fields in three dimensional.This measuring device has the advantages of recording the variation of temperature and three dimensional magnetic field quickly and accurately,high degree of visualization and flexible operation.The device consists of hardware module and software system,the hardware module is composed of four parts:3D hall probe array,T type thermocouple array,data acquisition system and host computer;we developed the software system based on a virtual instrument software development environment is based on G language launched by American National Instruments Company.According to the research subject we have programmed six function modules:sensor setting module?data acquisition module?data cut and storage module?filter module and modified data module,and we have analyzed these modules in detail.In addition,the 3D magnetic fields at different locations from the center to the edge of a single domain GdBCO bulk(32 mm in diameter)and a single domain GdBCO ring(10 mm and 32 mm for the inner and outer diameter)have been measured and recorded at 77 K under zero field cooled state.It reveals the mechanism of the magnetic field spreading,moving and escaping inside the GdBCO superconductor and the law of flux creeping with the changing of the applied magnetic field.