Field dependent surface resistance of niobium on copper cavities

@article{Junginger2014FieldDS,
  title={Field dependent surface resistance of niobium on copper cavities},
  author={Tobias Junginger},
  journal={Physical Review Special Topics-accelerators and Beams},
  year={2014},
  volume={18},
  pages={072001}
}
  • T. Junginger
  • Published 2 December 2014
  • Materials Science, Physics
  • Physical Review Special Topics-accelerators and Beams
The surface resistance ${R}_{\mathrm{S}}$ of superconducting cavities prepared by sputter coating a niobium film on a copper substrate increases significantly stronger with the applied rf field compared to cavities of bulk material. A possible cause is that the thermal boundary resistance between the copper substrate and the niobium film induces heating of the inner cavity wall, resulting in a higher ${R}_{\mathrm{S}}$. Introducing helium gas in the cavity, and measuring its pressure as a… 

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References

SHOWING 1-10 OF 15 REFERENCES

Effect of low-temperature baking on the radio-frequency properties of niobium superconducting cavities for particle accelerators

Radio-frequency superconducting (SRF) cavities are widely used to accelerate a charged particle beam in particle accelerators. The performance of SRF cavities made of bulk niobium has significantly

A new instrument to measure the surface resistance of superconducting samples at 400 MHz

A 400-MHz niobium quadrupole resonator has been manufactured to study the rf properties of superconducting bulk and thin film samples at low temperatures. We describe the apparatus, i.e., the

Dependence of the residual surface resistance of superconducting radio frequency cavities on the cooling dynamics around Tc

We report a strong effect of the cooling dynamics through Tc on the amount of trapped external magnetic flux in superconducting niobium cavities. The effect is similar for fine grain and single

An experimental and theoretical study of the relation between magnetic field and current in a superconductor

  • A. PippardW. Bragg
  • Physics
    Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences
  • 1953
The penetration depth, λ, in superconducting tin at 0° K has been found to be capable of variation by the addition of impurity, 3% of indium causing it to be nearly doubled, although the

The surface impedance of superconductors and normal conductors: The Mattis-Bardeen theory

The contribution of the Mattis-Bardeen theory to the understanding of the surface impedance of superconductors and normal conductors is reviewed. The early theoretical and experimental studies of the

Superconducting TESLA cavities

The conceptional design of the proposed linear electron-positron collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with an accelerating gradient of Eacc >= 25 MV/m at a

The thermal expansion of copper at low temperatures

The thermal expansion of copper has been determined at temperatures down to 2 °K by means of an electrical capacitance technique. By measuring three-terminal capacitances in a ratio-transformer