DocumentCode
865595
Title
High slew rate large bandwidth integrated dc SQUID magnetometer for NMR applications
Author
Thomasson, S.L. ; Gould, C.M.
Volume
5
Issue
2
fYear
1995
fDate
6/1/1995 12:00:00 AM
Firstpage
3222
Lastpage
3225
Abstract
We have developed an integrated dc SQUID magnetometer, with additional positive feedback (APF) unmodulated SQUID electronics system for low frequency true NMR applications. We constructed our SQUID circuit using an 11-layer Nb/Al/AlO/sub x//Nb process. Our design modifies previous APF approaches by incorporating selectable, high resolution on-chip feedback resistance. The on-chip resistance selection allows us to maximize the SQUID gain, dV/d/spl Phi/, at the operating point. With the use of APF we have achieved a slew rate greater than 10/sup 6/ /spl Phi//sub 0//s, and a bandwidth of approximately 300 kHz, which is suitable for sensitive NMR measurements.<>
Keywords
NMR spectroscopy; SQUID magnetometers; circuit feedback; 300 kHz; Nb-Al-AlO-Nb; additional positive feedback; bandwidth; gain; integrated DC SQUID magnetometer; low frequency NMR; multilayer Nb/Al/AlO/sub x//Nb process; on-chip resistance; slew rate; Bandwidth; Circuits; Coils; Extraterrestrial measurements; Feedback; Frequency; Niobium; Nuclear magnetic resonance; Pulse amplifiers; SQUID magnetometers;
fLanguage
English
Journal_Title
Applied Superconductivity, IEEE Transactions on
Publisher
ieee
ISSN
1051-8223
Type
jour
DOI
10.1109/77.403277
Filename
403277
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