A facility for cryogenic ion irradiation and in situ characterization of rare-earth barium copper oxide superconducting tapes

Superconducting magnets based on Rare Earth Barium Copper Oxides (REBCO) offer transformative capabilities in the fields of fusion energy, high energy physics, and space exploration. A challenge shared by these applications is the limited lifetime of REBCO due to radiation damage sustained during operation. Here we present a new ion-beam facility that enables simultaneous cryogenic irradiation and in situ characterization of commercial REBCO tapes. The ion source provides spatially uniform fluxes up to 1018 protons/m2s with kinetic energies up to 3.4 MeV, in addition to helium and higher-Z species. Using this facility, we can induce uniform damage profiles in the first 10–20 µm of REBCO tapes with less than 0.25 appm of hydrogen implanted in REBCO after a dose of 1020 protons/m2. The tape can be held between 20 and 300 K with an accuracy of ±0.1 K and is connected to a four-point probe measuring the critical current, Ic, and critical temperature, Tc, before, during, and after irradiation with transport current ranging from 100 nA to 100 A, and a typical voltage noise less than 0.1 μV. These capabilities are presently used to study the effect of irradiation temperature on REBCO performance change during and after proton bombardment, to assess the possibility of Ic and Tc recovery after irradiation through thermal annealing, and to explore the instantaneous and recoverable suppression of Ic and Tc observed during irradiation.基于稀土钡铜氧化物（Rare Earth Barium Copper Oxides, REBCO）的超导磁体，在聚变能源、高能物理与太空探索领域展现出变革性的应用价值。此类应用共同面临的核心挑战在于：REBCO材料在运行过程中会遭受辐射损伤，导致其服役寿命受限。为此，本文报道了一套新型离子束装置，可实现商用REBCO带材的同步低温辐照与原位表征。该装置的离子源可提供空间均匀的粒子通量，最高可达10¹⁸质子/（平方米·秒），动能上限为3.4 MeV；同时可兼容氦离子及更高原子序数的粒子辐照。利用这套装置，能够在REBCO带材的表层10–20 μm范围内诱导出均匀的损伤分布，且当辐照剂量达到10²⁰质子/平方米时，植入REBCO中的氢原子浓度低于0.25原子每百万（appm）。该样品夹持系统可将带材温度维持在20~300 K区间内，控温精度达±0.1 K；装置搭载四探针测试系统，可在辐照前、辐照过程中及辐照结束后，通过范围为100 nA至100 A的传输电流，同步测量临界电流（Ic）与临界温度（Tc），其典型电压噪声低于0.1 μV。目前，这套装置已被用于开展多项相关研究：包括探究辐照温度对质子辐照期间及辐照后REBCO性能变化的影响，评估辐照后通过热退火实现临界电流与临界温度恢复的可行性，以及探索辐照过程中观测到的临界电流与临界温度的瞬时可逆抑制效应。