Document Type

Conference Paper

Publication Date




Publication Title

Proceedings of the 13th International Particle Accelerator Conference



Conference Name

13th International Particle Accelerator Conference, 12-17 June 2022, Bangkok, Thailand


Niobium is the material of choice to build superconducting radio frequency (SRF) cavities, which are fundamental building blocks of modern particle accelerators. These cavities require a cryogenic cool-down to ~2 - 4 K for optimum performance minimizing RF losses on the inner cavity surface. However, temperature-independent residual losses in SRF cavities cannot be prevented entirely. One of the significant contributor to residual losses is trapped magnetic flux. The flux trapping mechanism depends on different factors, such as surface preparations and cool-down conditions. We have developed a diagnostic magnetic field scanning system (MFSS) using Hall probes and anisotropic magneto-resistance sensors to study the spatial distribution of trapped flux in 1.3 GHz single-cell cavities. The first result from this newly commissioned system revealed that the trapped flux on the cavity surface might redistribute with increasing RF power. The MFSS was also able to capture significant magnetic field enhancement at specific cavity locations after a quench.


© 2022 by JACoW

Published under a Creative Commons Attribution 3.0 Unported (CC BY 3.0) license.

Original Publication Citation

Parajuli, I. P., Ciovati, G., Delayen, J. R., & Gurevich, A. V. (2022). Magnetic field mapping of 1.3 GHz superconducting radio frequency niobium cavities. In F. Zimmerman, H. Tanaka, P. Sudmuang, P. Klysubun, P. Sunwong, T. Chanwattana, C. Petit-Jean-Genaz, & V.R.W. Schaa (Eds.), Proceedings of the 13th International Particle Accelerator Conference (pp. 1319-1322). Joint Accelerator Conferences Website.


0000-0003-0759-8941 (Gurevich)