Title :
A direct readout high-T/sub c/ dc SQUID electronics with ac bias and a liquid-nitrogen-cooled preamplifier
Author :
Gudoshnikov, S.A. ; Matveets, L.V. ; Weidl, R. ; Dorrer, L. ; Seidel, P. ; Krasnosvobodtsev, S.I. ; Kalabukhov, A.S. ; Snigirev, O.V.
Author_Institution :
Inst. of Terrestrial Magnetism, Ionosphere & Radiowave Propagation, Acad. of Sci., Troitsk, Russia
fDate :
6/1/1999 12:00:00 AM
Abstract :
Direct readout dc SQUID electronics based on a liquid-nitrogen-cooled preamplifier and alternating current bias was developed. The preamplifier with an intrinsic voltage noise of 0.18 nV/Hz/sup 1/2/ was used as the first stage of this electronics. A mathematical description of the noise suppression by this electronics was done. Low-frequency noise was reduced by a factor of 6 at 1 Hz by this technique.
Keywords :
SQUIDs; high-temperature superconductors; preamplifiers; readout electronics; superconducting device noise; AC bias; DC SQUID; direct readout electronics; high T/sub c/ superconductor; liquid-nitrogen-cooled preamplifier; noise suppression; Capacitors; Councils; Critical current; Fluctuations; Frequency locked loops; High temperature superconductors; Preamplifiers; Readout electronics; SQUIDs; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
