Related papers: Challenges and opportunities of srf theory for nex…
Performance of superconducting resonators, particularly cavities for particle accelerators and micro cavities and thin film resonators for quantum computations and photon detectors has been improved substantially by recent materials…
An increase in the quality factor of superconducting radiofrequency cavities is achieved by minimizing the surface resistance during processing steps. The surface resistance is the sum of temperature independent residual resistance and…
Magnetic field enhancement has been studied in the past through replica and cavity cutting. Considerable progress of niobium cavity manufacturing and processing has been made since then. Wide variety of single cell cavities has been…
Superconducting rf technology (SRF) is evolving rapidly as are its applications. While there is active exploitation of what one may term the current state-of-the-practice, there is also rapid progress expanding in several dimensions the…
Radio frequency superconductivity is a cornerstone technology for many future HEP particle accelerators and experiments from colliders to proton drivers for neutrino facilities to searches for dark matter. While the performance of…
Q-slope issue, which is caused by the field dependent surface resistance, puzzled people for a long time in SRF fields. In this paper, we related the Q-slope with surface treatments; and proposed a surface-impurity model to explain the…
The surface resistance of an RF superconductor depends on the surface temperature, the residual resistance and various superconductor parameters, e.g. the energy gap, and the electron mean free path. These parameters can be determined by…
Recently reported anomalies in frequency shift of order $\delta f\sim 0.1 -10\,\mbox{kHz}$ for Niobium SRF cavities in a narrow temperature region near $T_c\simeq 9\,\mbox{K}$ are sensitive to the surface preparation and Nitrogen doping. We…
Niobium superconducting radio-frequency (SRF) cavities for high energy accelerator applications have been greatly improved in terms of the quality factor $Q$ by techniques such as Nitrogen doping. However, the mechanisms leading improvement…
Superconducting RadioFrequency (SRF) cavities have been developed for modern particle accelerator projects in the world. These cavities are mainly made of bulk niobium operated in superfluid or normal fluid helium. Due to the price increase…
Recent developments in superconducting radio-frequency (SRF) research have focused primarily on high frequency elliptical cavities for electron accelerators. Advances have been made in both reducing RF surface resistance and pushing the…
In niobium superconducting radio frequency (SRF) accelerating cavities a decrease of the quality factor at lower fields - a so called \emph{low field Q slope or LFQS} - has been a long-standing unexplained effect. By extending the high $Q$…
Theoretical limits to the performance of superconductors in high magnetic fields parallel to their surfaces are of key relevance to current and future accelerating cavities, especially those made of new higher-Tc materials such as Nb$_3$Sn,…
A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Breakdown of the surface barrier against magnetic flux penetration at the cavity equator is…
Bulk niobium has long been the material of choice for superconducting radio-frequency applications. An alternative approach is the superconductor-insulator-superconductor multilayer structure, which enables the use of brittle high-$T_c$…
Superconducting radio-frequency (SRF) cavities coupled to transmon circuits have proven to be a promising platform for building high-coherence quantum information processors. An essential aspect of this realization involves designing high…
Motivated by the problem of the residual surface resistance of the superconducting radio-frequency (SRF) cavities, we develop a microscopic theory of the surface impedance of s-wave superconductors with magnetic impurities. We analytically…
As progress towards real implementations of cryogenic high gradient normal conducting accelerating cavities continues, a more mature understanding of the surface physics in this novel environment becomes increasingly necessary. To this end,…
In this talk, I introduce the proposed next superconducting radio-frequency (SRF) technologies that will make it possible to achieve much higher accelerating electric field than the present SRF technologies. Audiences are assumed to be…
We present results for the resonant frequency shift and quality factor of disordered Nb SRF cavities driven out of equilibrium by the resonant microwave field. The theory is based on the nonequilibrium theory of superconductivity for the…