Influence of Resonances on the Noise Performance of SQUID Susceptometers

Autor: Samantha I. Davis, John R. Kirtley, Kathryn A. Moler
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Sensors, Vol 20, Iss 1, p 204 (2019)
Druh dokumentu: article
ISSN: 1424-8220
DOI: 10.3390/s20010204
Popis: Scanning Superconducting Quantum Interference Device (SQUID) Susceptometry simultaneously images the local magnetic fields and susceptibilities above a sample with sub-micron spatial resolution. Further development of this technique requires a thorough understanding of the current, voltage, and flux ( I V Φ ) characteristics of scanning SQUID susceptometers. These sensors often have striking anomalies in their current−voltage characteristics, which we believe to be due to electromagnetic resonances. The effect of these resonances on the performance of these SQUIDs is unknown. To explore the origin and impact of the resonances, we develop a model that qualitatively reproduces the experimentally-determined I V Φ characteristics of our scanning SQUID susceptometers. We use this model to calculate the noise characteristics of SQUIDs of different designs. We find that the calculated ultimate flux noise is better in susceptometers with damping resistors that diminish the resonances than in susceptometers without damping resistors. Such calculations will enable the optimization of the signal-to-noise characteristics of scanning SQUID susceptometers.
Databáze: Directory of Open Access Journals
Nepřihlášeným uživatelům se plný text nezobrazuje