Understanding mechanism of performance improvement in nitrogen-doped niobium superconducting radio frequency cavity
Understanding mechanism of performance improvement in nitrogen-doped niobium superconducting radio frequency cavity
复制标题
理解掺氮铌超导射频腔性能提升机理
DOI：
10.1080/21663831.2022.2126737
复制
发表时间：
2022
影响因子：
8.3
通讯作者：
Lin Zhou
中科院分区：
文献类型：
--
作者：
Xiaotian Fang;Jin;M. Kramer;A. Romanenko;A. Grassellino;J. Zasadzinski;Lin Zhou
摘要 铌超导射频腔可在现代加速器和量子计算机中应用。然而，表面电阻会显着降低腔体的性能。氮掺杂表面处理可以通过降低表面电阻来持续提高腔体性能，但其改善机制尚不完全清楚。在这里，我们采用透射电子显微镜和光谱学来揭示未掺杂和氮掺杂腔之间 Nb/空气界面的结构和化学差异。结果表明，氮掺杂通过在铌/空气界面附近引入压应力/应变来钝化铌表面，从而阻碍氧和氢原子的扩散并减少表面氧化物厚度。图解摘要影响陈述对非掺杂和氮掺杂铌腔的铌/空气界面进行全面的结构和化学研究有助于了解氮掺杂腔的性能改进机制。
ABSTRACT Niobium superconducting radiofrequency cavities enable applications in modern accelerators and quantum computers. However, the surface resistance significantly deteriorates the cavities’ performance. Nitrogen doping surface treatment can consistently increase cavity performance by reducing surface resistance, but the improvement mechanism is not fully understood. Herein, we employed transmission electron microscopy and spectroscopy to uncover the structural and chemical differences of the Nb/air interface between the non-doped and nitrogen-doped cavities. The results indicate that nitrogen doping passivates the Nb surface by introducing a compressive stress/strain close to the Nb/air interface, which impedes the diffusion of oxygen and hydrogen atoms and reduces surface oxide thickness. GRAPHICAL ABSTRACT IMPACT STATEMENT A comprehensive structural and chemical study of the Nb/air interface from the non-doped and nitrogen-doped niobium cavity helps to understand the performance improvement mechanisms of the nitrogen-doped cavity.