Field-Enhanced Superconductivity in High-Frequency Niobium Accelerating Cavities
Field-Enhanced Superconductivity in High-Frequency Niobium Accelerating Cavities
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高频铌加速腔中的场增强超导
DOI：
10.1103/physrevlett.121.224801
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发表时间：
2018
影响因子：
8.6
通讯作者：
Sergatskov, D. A.
中科院分区：
文献类型：
--
作者：
Martinello, M.;Checchin, M.;Romanenko, A.;Grassellino, A.;Aderhold, S.;Chandrasekeran, S. K.;Melnychuk, O.;Posen, S.;Sergatskov, D. A.
氮掺杂处理的发现揭示了当氮杂质作为杂质溶解在材料中时，铌谐振器的射频表面电阻可以显著降低。N掺杂腔表现出的一种特殊行为是反斜率，即，作为加速场的函数的表面电阻的温度依赖分量的减少。这种表面电阻行为的不寻常趋势归因于掺杂处理后铌晶格中间隙氮的存在。这封信重点研究了表面电阻的温度相关分量与场的依赖性，作为腔谐振频率的函数。研究结果表明，如果谐振频率足够高，即使在干净的铌腔中也可能出现反斜率，这为理解反斜率效应提供了新的途径。
The discovery of nitrogen-doping treatment revealed that the radio frequency surface resistance of niobium resonators may be significantly reduced when nitrogen impurities are dissolved as interstitials in the material. A peculiar behavior exhibited by N-doped cavities is the anti-slope, i.e., a reduction in the temperature-dependent component of the surface resistance as a function of the accelerating field. This unusual trend in the surface resistance behavior has been attributed to the presence of interstitial nitrogen in the niobium lattice after the doping treatment. This Letter presents a focused study on the field dependence of the temperature-dependent component of the surface resistance as a function of the cavity resonant frequency. The findings show that the anti-slope may appear even in clean niobium cavities if the resonant frequency is high enough, which suggests new routes toward understanding the anti-slope effect.