| Zugriffsnummer | 16262 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Sprache | Englisch |
| Titel | High-Tc SQUID sensors with integrated earth field compensation |
| Autor(in); Institution |
Drung, Dietmar; 7.13, Kryosensorik, PTB-Berlin
Schurig, Thomas; 7.13, Kryosensorik, PTB-Berlin
|
| Quelle/Jahr | IEEE Transactions on Applied Superconductivity: 13 (2003), 2, 751 - 754 |
| ISSN | 1051-8223 |
| DOI | |
| Verlag | New York, NY: IEEE |
| Konferenzangaben | The 2002 Applied Superconductivity Conference, Houston, TX, 4-9, August, 2002, USA |
| Freie Schlagworte | Earth field compensation ; low-noise current source ; SQUID encapsulation |
| Zusammenfassung | An encapsulation with integrated field compensation coils for superconducting quantum interference device (SQUID) magnetometers is presented. The capsule is fabricated from printed-circuit board material. In spite of the small capsule size of 18 mm x 16 mm x 4.8 mm, the compensation field at nominal capsule dimensions is homogeneous to about ±2% over the area of the SQUID magnetometer pickup coil of 9 mm x 9 mm. The field homogeneity degrades by about a factor of two for worst-case tolerances in the thickness of the board material or in the positions of the field coils. A low-noise current source was integrated into our microcontroller-based SQUID readout electronics in order to supply the field coils. Compensation fields of up to ± 71 μT can be produced with only 19 fT/√Hz excess noise above the 1/f corner at about 2 Hz. The current source has a 10%-90% settling time of 2.2 ms allowing one to compensate the background field dynamically in environments with very large low-frequency field fluctuations or even in slowly moved sensor systems. |
