The Design Of Quench Detection System Of The Super-conductor Performance Test Facility And Experiments

The Super-conductor Performance Test Facility(SOST)is an important components of Comprehensive Research Facility(CRAFT)for Fusion Technology.The background field magnet system that can provide a magnetic field of up to 15 T is the core system of the entire facility.The background field magnet system usually runs kA-level current and stores MJ energy.Once quench occurs,the stored energy will be converted into heat in the form of ohmic heat,which will damage conductors and equipment.Therefore,the quench detection system is essential for safety of the superconducting magnet system.Based on the calculation and analysis of the background field magnet system structure and electromagnetic parameters,as well as the quench simulation and analysis of the CICC conductor,this paper design the quench detection system for background field magnets of SOST.In addition,this article also carried out research on two key technologies of the quench detection system.Firstly,in terms of the interference of the quench detection system,this paper has carried out the research of the influence of the Nb3Sn magnet flux jump phenomenon on the quench detection system.According to the theory of magnetic flux jumping adiabatic stabilization,the magnetic flux jumping phenomenon of high-performance Nb3Sn magnets is analyzed,and a high-speed acquisition system and experimental platform is built to conduct exploration experiments,and a solution to the interference of the quench detection system based on the magnetic flux jumping phenomenon is proposed.Next,from the perspective of new quench detection technology,this paper proposes a distributed optical fiber current lead temperature monitoring system.This method is based on the structure and operating characteristics of the current leads,the study of the quench propagation characteristics of high temperature superconducting and the advantages of distributed optical fiber sensing technology,which has the characteristic of spatial continuous distribution detection and complete avoidance of electromagnetic interference.Corresponding tests were also carried out in this article.