| Zugriffsnummer | 22976 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Novel SQUID current sensors with high linearity at high frequencies |
| Autor(in); Institution |
Drung, Dietmar; 7.5, Kryo- und Vakuumphysik, PTB-Berlin
Beyer, Jörn; 7.5, Kryo- und Vakuumphysik, PTB-Berlin
Peters, Margret; 7.5, Kryo- und Vakuumphysik, PTB-Berlin
Storm, Jan-Hendrik; 7.5, Kryo- und Vakuumphysik, PTB-Berlin
Schurig, Thomas; 7.5, Kryo- und Vakuumphysik, PTB-Berlin
|
| Quelle/Jahr | IEEE Transactions on Applied Superconductivity: 19 (2009), 3,1, 772 - 777 |
| ISSN | 1051-8223 |
| DOI | |
| Verlag | New York, NY: Inst. |
| Konferenzangaben | Applied Superconductivity Conference 2008, Chicago, August 17 - 22, 2008, USA |
| Freie Schlagworte | nonlinear distortion ; output current feedback ; SQUID current sensor ; transimpedance amplifier |
| Zusammenfassung | We have developed novel SQUID current sensors consisting of a sensitive 16-SQUID input stage followed by an output stage of 40, 160, or 640 low-inductance SQUIDs. A highly gradiometric design of the individual SQUIDs with ≈5 μm maximum linewidth makes the devices insensitive to external magnetic noise and allows cool-down and operation in the Earth magnetic field. Output current feedback (OCF) is used to increase the linear signal range. When driving a terminated 50 Ω coaxial cable, the sensor with 160 output SQUIDs exhibits a signal range of one flux quantum Φ0 at a power dissipation of about 100 nW. At 10 MHz and 4.2 K, a total flux noise level of 0.34 μΦo/√Hz is achieved corresponding to a dynamic range of ±1.5×106 √Hz. At higher frequencies, interaction of preamplifier voltage noise with the output cable impedance increases the sensor noise (a general problem in high-speed SQUID systems). The small-signal bandwidth is )200 MHz. A very high slew rate of )50 Φ0/μs is achieved allowing one to use the full signal range at frequencies up to 16 MHz with a total harmonic distortion below ≈1%. |
