High Tc DC SQUID and flux transformer development

Alistair A. Fife; V. Angus; K. Betts; Max Burbank; R. A. Cragg; K. Ferguson; N. Fortier; Philip R. Kubik; F. Habib; J. Nomura; M. Smith; P. Spear; J. Vrba; Dale Wager; W. Westera; H. Zhou

doi:10.1117/12.180993

2 July 1994 High T_c DC SQUID and flux transformer development

Alistair A. Fife, V. Angus, K. Betts, Max Burbank, R. A. Cragg, K. Ferguson, N. Fortier, Philip R. Kubik, F. Habib, J. Nomura, M. Smith, P. Spear, J. Vrba, Dale Wager, W. Westera, H. Zhou

Author Affiliations +

Proceedings Volume 2160, Superconductive Devices and Circuits; (1994) https://doi.org/10.1117/12.180993
Event: OE/LASE '94, 1994, Los Angeles, CA, United States

Abstract

A description is presented of the fabrication and properties of high Tc DC SQUIDs and flux transformers fabricated by dry processing of pulsed laser ablated YBa₂Cu₃O_7-x (YBCO) thin films. SQUIDs have been fabricated with either bicrystal substrate or step edge junctions. For all devices fabricated thus far, measurements indicate a similar character to the flux noise spectra with a significant 1/f noise component below 100-500 Hz. The transfer function and energy sensitivities as a function of SQUID inductances in the range 60-200 pH have been measured for bicrystal DC SQUIDs and compared with estimates. Various techniques have been employed to improve the magnetic field sensitivity of the uncoupled DC SQUID toward more practical levels including the use of large area washers, single layer magnetometers and 3-level flux transformers fabricated from trilayers of YBCO/SrTiO₃YBCO. The properties of open input coils are presented as well as the performance of closed loop transformers coupled via flip chip geometry to the SQUID washer. A white magnetic noise level of approximately equals 130 fT rms/(root) Hz above 200 Hz has been reached with a flux transformer with a 15 turn input coil and pick-up loop area of 13 mm².

Citation Download Citation

Alistair A. Fife, V. Angus, K. Betts, Max Burbank, R. A. Cragg, K. Ferguson, N. Fortier, Philip R. Kubik, F. Habib, J. Nomura, M. Smith, P. Spear, J. Vrba, Dale Wager, W. Westera, and H. Zhou "High T_c DC SQUID and flux transformer development", Proc. SPIE 2160, Superconductive Devices and Circuits, (2 July 1994); https://doi.org/10.1117/12.180993

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available