Determination of the magnetic field dependence of the surface resistance of superconductors from cavity tests

TL;DR

This paper introduces a method to determine how the surface resistance of superconductors varies with magnetic field, using cavity test data, applicable to various cavity geometries.

Contribution

A general approach is developed to extract magnetic field dependence of surface resistance from cryogenic cavity test Q-curves, applicable to multiple cavity types.

Findings

Method successfully applied to coaxial and elliptical cavities

Enables analysis of complex cavity geometries

Provides insights into superconductor performance under magnetic fields

Abstract

We present a general method to derive the magnetic field dependence of the surface resistance of superconductors from the Q-curves obtained during the cryogenic tests of cavities. The results are applied to coaxial half-wave cavities, TM-like "elliptical" accelerating cavities, and cavities of more complicated geometries.