铌SRF腔中由于表面结构引起的线性RF损耗机制对中场Q斜率的贡献
Contribution to mid-field Q slope in Niobium SRF cavities from linear RF loss mechanism due to topographic surface structures
摘要：
超导射频（SRF）表面上的拓扑结构可以贡献额外的腔RF损耗，其可以根据波散射理论的表面RF反射率和吸收指数来描述。在各向同性均匀程度下，引入粗糙度功率谱密度（PSD），量化了随机表面形貌结构。比较了缓冲化学抛光（BCP）、电解抛光（EP）、纳米机械抛光（NMP）和滚筒离心抛光（CBP）等不同表面处理方法对铌的PSD的影响。基于PSD统计分析，利用扰动模型计算附加粗糙表面RF损耗。该模型不考虑超导体在高于跃迁场的磁场下变为正常导电。可以从线性损耗机制计算在该场范围内粗糙表面和理想光滑表面之间的RF功率耗散比。
英文摘要：
Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous extent, Power Spectrum Density (PSD) of roughness is introduced and quantifies the random surface topographic structure. PSD obtained from different surface treatments of niobium, such Buffered Chemical Polishing (BCP), Electropolishing (EP), Nano-Mechanical Polishing (NMP) and Barrel Centrifugal Polishing (CBP) are compared. A perturbation model is utilized to calculate the additional rough surface RF losses based on PSD statistical analysis. This model will not consider that superconductor becomes normal conducting at fields higher than transition field. One can calculate the RF power dissipation ratio between rough surface and ideal smooth surface within this field range from linear loss mechanisms.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
