Title :
Performance of a flux locked series SQUID array
Author :
Foglietti, V. ; Stawiasz, K.G. ; Ketchen, M.B. ; Koch, R.H.
Author_Institution :
IBM Thomas J. Watson Res. Center, Yorktown Heights, NY, USA
Abstract :
The operation of a SQUID array with 100 DC SQUIDs has been demonstrated using a single flux-locked loop. The SQUID array had a maximum dynamic range of +or-1.3*10/sup 8// square root (Hz) in the low frequency region, a high slewing rate over a wide frequency range, and an extrinsic white noise energy sensitivity of 6*10/sup -31/J/Hz. These data were obtained with a very simple feedback circuit made from three inexpensive operational amplifiers that operated in the DC-feedback mode. The feedback loop did not have any impedance matching circuit between the SQUID array and the room temperature electronics. Our results show that a SQUID array can have a significant impact on those applications that demand good noise performance and a very high dynamic range.<>
Keywords :
SQUIDs; electron device noise; feedback; linearisation techniques; magnetometers; white noise; DC SQUIDs; DC-feedback mode; extrinsic white noise energy sensitivity; feedback circuit; flux locked series SQUID array; high dynamic range; high slewing rate; operational amplifiers; single flux-locked loop; Dynamic range; Feedback circuits; Feedback loop; Frequency; Impedance matching; Low-noise amplifiers; Operational amplifiers; SQUIDs; Temperature sensors; White noise;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
