Observation of quenching-induced magnetic flux trapping using a magnetic field and temperature mapping system

• Published in: Physical review. Accelerators and beams Vol. 25; no. 8; p. 082002
• Main Authors: Okada, Takafumi, Kako, Eiji, Masuzawa, Mika, Sakai, Hiroshi, Ueki, Ryuichi, Umemori, Kensei, Tajima, Tsuyoshi
• Format: Journal Article
• Language: English
• Published: College Park American Physical Society 01.08.2022; American Physical Society (APS)
• Subjects: accelerator design, technology, and operations; Heat loss; Magnetic fields; Magnetic flux; Mapping; PARTICLE ACCELERATORS; Quenching; Superconducting devices; superconducting RF; Superconductivity; Surface resistance; Trapping
• ISSN: 2469-9888; 2469-9888
• DOI: 10.1103/PhysRevAccelBeams.25.082002

Highly efficient superconducting radio-frequency cavities exhibit low heat loss and are used as components in accelerators and superconducting devices due to their highQ-values. The precise location of magnetic flux trapping in cavities is necessary to identify its effects on the performance of superconducting cavities. In this study, we report a new combined mapping system to measure the temperature and magnetic field on the equator. The proposed system comprehensively maps local magnetic field changes as magnetic flux trapping due to quenching. Our experimental results show that magnetic flux trapping due to quenching increases the local surface resistance of superconducting cavities at 2 K. Thus, the proposed system elucidates the relationship between local flux trapping due to quenching and surface resistance in superconducting cavities and highlights the effect of quenching on the surface resistance. This system can aid in the development of superconducting cavities with higherQvalues.