Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography

Xu, Chen; Reece, Charles E.; Kelley, Michael J.; Takacs, Peter

doi:10.1016/j.nima.2018.05.004

Title: Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography

Abstract

Minimization of Radio-Frequency (RF) dissipation on superconducting surfaces is of interest for many applications. A prominent one is the use of Superconducting RF (SRF) cavities for charged particle acceleration. In addition to our previous investigation which characterized the occurrence of high-field non-linear losses by microscopic surface topography, the topic of increased linear losses as a function of surface topographic character merits consideration. Surfaces with isotropic homogeneous surface topography may be well characterized by power spectral density (PSD) derived from systematic height measurements. PSD characterizations of representative niobium cavity surface treatments have been developed: Electro-Polishing (EP), Nano-Mechanical Polishing (NMP) and Centrifugal Barrel Polishing (CBP) A perturbation model based on PSD statistical analysis is used to calculate additional RF loss on these surfaces when superconducting. The model assesses the penetration depth effects for a superconductor. We thus estimate the RF power dissipation ratio between these rough surfaces and an ideal smooth surface.

Authors:

Xu, Chen ^[1]; Reece, Charles E. ^[2]; Kelley, Michael J. ^[3]; Takacs, Peter ^[4]

Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States)
Brookhaven National Lab. (BNL), Upton, NY (United States)

Publication Date:: 2018-05-21

Research Org.:: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Nuclear Physics (NP)

OSTI Identifier:: 1458441

Alternate Identifier(s):: OSTI ID: 1548207

Report Number(s):: JLAB-ACC-17-2623; DOE/OR/23177-4308
Journal ID: ISSN 0168-9002; PII: S0168900218305898; TRN: US1901429

Grant/Contract Number:: AC05-06OR23177

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

Additional Journal Information:: Journal Volume: 904; Journal ID: ISSN 0168-9002

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

Citation Formats


                    Xu, Chen, Reece, Charles E., Kelley, Michael J., and Takacs, Peter. Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography.  United States: N. p., 2018. 
Web.  doi:10.1016/j.nima.2018.05.004.

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                    Xu, Chen, Reece, Charles E., Kelley, Michael J., & Takacs, Peter. Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography.  United States.  https://doi.org/10.1016/j.nima.2018.05.004

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                    Xu, Chen, Reece, Charles E., Kelley, Michael J., and Takacs, Peter. Mon .  
"Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography".  United States.  https://doi.org/10.1016/j.nima.2018.05.004.  https://www.osti.gov/servlets/purl/1458441.

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@article{osti_1458441,

  title        = {Enhancement of effective linear RF surface resistance of superconducting surfaces by microscopic topography},

  author       = {Xu, Chen and Reece, Charles E. and Kelley, Michael J. and Takacs, Peter},

  abstractNote = {Minimization of Radio-Frequency (RF) dissipation on superconducting surfaces is of interest for many applications. A prominent one is the use of Superconducting RF (SRF) cavities for charged particle acceleration. In addition to our previous investigation which characterized the occurrence of high-field non-linear losses by microscopic surface topography, the topic of increased linear losses as a function of surface topographic character merits consideration. Surfaces with isotropic homogeneous surface topography may be well characterized by power spectral density (PSD) derived from systematic height measurements. PSD characterizations of representative niobium cavity surface treatments have been developed: Electro-Polishing (EP), Nano-Mechanical Polishing (NMP) and Centrifugal Barrel Polishing (CBP) A perturbation model based on PSD statistical analysis is used to calculate additional RF loss on these surfaces when superconducting. The model assesses the penetration depth effects for a superconductor. We thus estimate the RF power dissipation ratio between these rough surfaces and an ideal smooth surface.},

  doi          = {10.1016/j.nima.2018.05.004},

  journal      = {Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment},

  number       = ,

  volume       = 904,

  place        = {United States},

  year         = {2018},

  month        = {5}

}

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Figures / Tables:

Figure 1: A plane wave incident impinging on a rough surface with incident angle $θ$_$i$, while $k$₁ and $k$_$x$ are the total surface roughness frequency vector and its x axis projection.

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