# Fluxon-induced losses in niobium thin-film cavities revisited

## TL;DR

This paper revisits long-standing data on niobium thin-film cavities using a modified London model to analyze RF superconductivity and flux-induced losses, providing new insights into their dependence on various parameters.

## Contribution

It introduces a modified London model to better understand RF losses and trapped flux effects in niobium thin-film cavities, expanding on previous analyses.

## Key findings

- The model fits BCS surface resistance data across different conditions.
- RF losses from trapped flux depend on magnetic field, temperature, and mean free path.
- Revised understanding of flux-induced losses in superconducting cavities.

## Abstract

Long standing data from niobium thin film accelerating cavities will be revisited and analysed by a modified London model of RF superconductivity. Firstly, the applicability of this model is explored using data of the BCS surface resistance and its dependence on the RF magnetic field, temperature and mean free path. Secondly, the RF losses from trapped magnetic flux are analysed with regard to their dependence on these same parameters.

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Source: https://tomesphere.com/paper/1904.07160