Low-noise high-speed dc superconducting quantum interference device magnetometer with simplified feedback electronics
1990; American Institute of Physics; Volume: 57; Issue: 4 Linguagem: Inglês
10.1063/1.103650
ISSN1520-8842
AutoresD. Drung, R. Cantor, Mark Peters, Hans-Jürgen Scheer, H. Koch,
Tópico(s)Magnetic Field Sensors Techniques
ResumoA dc superconducting quantum interference device (SQUID) magnetometer has been integrated on a 9×9 mm2 chip with eight pick-up loops in parallel to directly form a SQUID inductance of about 0.5 nH. Very simple feedback electronics have been developed which do not require liquid-helium temperature impedance matching circuits or flux modulation techniques. The magnetometer has a typical white noise of 8 fT/(Hz)1/2 and a 1/f corner frequency below 3.5 Hz. With an additional positive feedback circuit at 4.2 K the white noise level has been further reduced to 4.5 fT/(Hz)1/2. Using a two-pole integrator, a 3 dB bandwidth around 0.5 MHz and a maximum slew rate of 3 mT/s at 1.3 kHz have been attained with a ±0.4 μT feedback range.
Referência(s)