Meter-length REBCO ultralow resistance joint for the gigahertz NMR magnet  

作　　者：Xiaoru Tian Hongli Suo Zili Zhang Maolai Ye Lei Wang Jianhua Liu Qiuliang Wang 

机构地区：[1]Key Laboratory of Advanced Functional Materials,Ministry of Education,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100022,China [2]Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Key Laboratory of High Density Electromagnetic Power and Systems,Chinese Academy of Sciences,Institute of Electrical Engineering,Beijing 100190,China

出　　处：《Superconductivity》2024年第4期112-121,共10页超导(英文)

基　　金：National Key R&D Program of China(2022YFA1605200);National Natural Science Foundation of China(52277021,52293421,52293422,52325701 and U23A6003);Beijing Municipal Natural Science Foundation(3232055);Key Research Program of Frontier Sciences,CAS(ZDBS‐LY‐JSC039).

摘　　要：In this paper,we present a meter‐length REBCO joint using the most conventional soldering method.The joint resistance can attain 7.21×10^(‐11)Ωat 4.2 K with a joint length of 2 m.It essentially displays a linear relation-ship with the joint length.The microstructures of the joints were investigated systematically using scanning electron microscopy(SEM)and micro‐computed tomography(micro‐CT).Multiple voids were identified in all the joints.More importantly,the voids were not distributed homogeneously.The internal voids near the innermost and outermost rings were larger than those in the middle ring.Two types of gigahertz magnetic res-onance spectroscopy(NMR)magnets were designed:15 T low temperature superconductor(LTS)+15 high temperature superconductor(HTS)and whole HTS.The current 10^(‐11)Ω‐level joint can satisfy the magnetic field decay criterion of 1×10^(‐8)/h.However,a pure HTS gigahertz NMR magnet requires a joint length of over 20 m,which is not feasible.The current resistance resource of the meter‐length joint was also discussed by an equivalent circuit analysis.This paper presents a reliable engineering REBCO joint fabrication method for giga-hertz NMR magnets without heat treatment.

关 键 词：REBCO Jaint Rsitance Miao-CT NMR magnet 

分 类 号：TM2[一般工业技术—材料科学与工程]