Uncertainty of data obtained in SRF cavity vertical test

TL;DR

This paper analyzes the uncertainties in data obtained from vertical tests of SRF cavities, highlighting the impact of algorithm choice on the accuracy of quality factor and gradient measurements.

Contribution

It introduces a first-principle method for analyzing data uncertainty in SRF cavity vertical tests, improving accuracy over previous algorithms.

Findings

The first-principle method provides more accurate uncertainty estimates.

Comparison shows previous methods underestimated uncertainties.

Results enhance reliability of SRF cavity qualification data.

Abstract

Vertical test is a commonly used experimental method to qualify Superconducting Radio Frequency (SRF) cavities. Taking the experiences at Jefferson Lab (JLab) in US for example, over thousand of vertical tests have been performed on over 500 different cavities up to now [1]. Most of the tests at JLab followed the method as described in [1], but all the uncertainties of the calculated quality factors as well as the gradients were in-accurate due to the wrong algorithm used. In this paper, a first-principle method was applied to analyze the uncertainty of the data, and the results were compared with those in [1] under typical experiment conditions.