Dark Current Measurements on a Superconducting Cavity using a Cryogenic Current Comparator

TL;DR

This paper demonstrates the use of a cryogenic current comparator to non-destructively measure dark currents in superconducting cavities within a challenging accelerator environment, achieving high sensitivity.

Contribution

It introduces a novel application of a superconducting CCC for dark current measurement in superconducting LINAC cavities under real-world conditions.

Findings

Sensitivity of 0.2 nA/√Hz achieved

Dark currents of 5 nA detectable

Effective non-destructive measurement method

Abstract

This paper presents non-destructive dark current measurements of superconducting TESLA cavities for superconducting LINACs. The measurements were carried out in a highly disturbed accelerator environment using a low temperature superconducting d.c. SQUID based Cryogenic Current Comparator (CCC). The overall current sensitivity under these rough conditions was measured to be 0.2 nA/sqrt(Hz) which enables the detection of dark currents of 5 nA.