Publications
Publication Information
| Title | Magnetic field sensors for detection of trapped flux in superconducting radio frequency cavities |
| Authors | Ishwari Parajuli, Gianluigi Ciovati, Jean Delayen |
| JLAB number | JLAB-ACC-21-3497 |
| LANL number | (None) |
| Other number | DOE/OR/23177-5316 |
| Document Type(s) | (Journal Article) |
| Category: | SRF Technology |
| Associated with EIC: | No |
| Supported by Jefferson Lab LDRD Funding: | No |
| Funding Source: | Nuclear Physics (NP) |
| Other Funding: | NSF Grant PHY 100614-010 |
|
Journal Compiled for Review of Scientific Instruments Volume 92 Page(s) 104705 Refereed | |
| Publication Abstract: | Superconducting radio-frequency (SRF) cavities are fundamental building block of modern particle accelerators. They operate at liquid helium temperatures 2-4 K to achieve very high quality factors 1e10-1e11. Trapping of magnetic flux within the superconductor is a significant contribution to the residual RF losses which limit the achievable quality factor. Suitable diagnostic tools are in high demand to understand the mechanisms of flux trapping in technical superconductors and the fundamental components of such diagnostic tool are magnetic field sensors. We have studied the performance of commercially available Hall probes, anisotropic magnetoresistive sensors and flux-gate magnetometers with respect to their sensitivity and capability to detect localized, low magnetic flux amplitudes, of the order of few tens of magnetic flux quantum at liquid helium temperature. Although Hall probes have the lowest magnetic field sensitivity (~96$ nV$/microT at 2 K), their physical dimensions are such that they have the ability to detect the lowest number of trapped vortices among the three type of sensors. Hall probes and anisotropic magnetoresistive sensors have been selected to be used in a setup to map regions of trapped flux on the surface of a single-cell SRF cavity. |
| Experiment Numbers: | other |
| Group: | SRF Research & Dev |
| Document: | |
| DOI: | https://doi.org/10.1063/5.0063177 |
| Accepted Manuscript: | RSI21-AR-01591_rev11.pdf |
| Supporting Documents: | |
| Supporting Datasets: | |