Linearity of a Digital SQUID Magnetometer
| Autor: | J. Kunert, Ronny Stolz, O. Mielke, Thomas Ortlepp, I. Haverkamp, Hannes Toepfer, Hans-Georg Meyer |
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| Rok vydání: | 2011 |
| Předmět: |
Physics
Squid biology Comparator Magnetometer Dynamic range Linearity Slew rate Condensed Matter Physics Magnetic flux Electronic Optical and Magnetic Materials law.invention Nuclear magnetic resonance law Condensed Matter::Superconductivity Rapid single flux quantum biology.animal Electronic engineering Electrical and Electronic Engineering |
| Zdroj: | IEEE Transactions on Applied Superconductivity. 21:705-708 |
| ISSN: | 1558-2515 1051-8223 |
| DOI: | 10.1109/tasc.2010.2087734 |
| Popis: | A digital SQUID magnetometer measures the magnetic field amplitude by counting integer magnetic flux quanta within its superconducting input loop. Although resolution is limited in comparison to analog SQUID systems, the digital SQUID is able to outrange its analog counterpart with regard to parameters such as slew rate and dynamic range. In this work we evaluate the performance of a digital SQUID based on a three-level logic. Due to this basic principle, we face a combination of two comparator grayzones leading to hysteretic behavior of the sensor that produces a “dead zone” in the signal reversal point. The dependence of the comparator threshold on design parameters is investigated by simulation studies and reconfirmed by experimental results. We were able to reach a total dynamic range of more than 540,000 flux quanta (about 19 bit) with a linearity error of about 5 bit due to the mentioned hysteretic behavior. We discuss the results of our investigations and provide guidelines to extend dynamic range and linearity for future sensor designs. |
| Databáze: | OpenAIRE |
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