DocumentCode
865488
Title
Use of a DC SQUID receiver preamplifier in a low field MRI system
Author
Seton, H.C. ; Bussell, D.M. ; Hutchison, J.M.S. ; Lurie, D.J.
Author_Institution
Dept. of Biomed. Phys. & Bioeng., Aberdeen Univ., UK
Volume
5
Issue
2
fYear
1995
fDate
6/1/1995 12:00:00 AM
Firstpage
3218
Lastpage
3221
Abstract
We have used tuned receiver coils coupled to a dc SQUID preamplifier in a small scale magnetic resonance imaging (MRI) system operating at 425 kHz (B/sub 0/=0.01 T). The coil and SQUID are cooled to 4.2 K in a modified biomagnetic cryostat. The modifications provide transparency to rf signals originating outside the cryostat while maintaining an acceptably low liquid helium boiloff rate. By applying negative feedback we have damped low loss, high Q-factor SQUID input circuits to achieve a useful imaging bandwidth of over 2 kHz.<>
Keywords
SQUID magnetometers; biomedical NMR; preamplifiers; 0.01 T; 2 kHz; 4.2 K; 425 kHz; DC SQUID receiver preamplifier; Q-factor; RF signals; biomagnetic cryostat; damping; liquid helium boiloff rate; loss; low field MRI system; magnetic resonance imaging; negative feedback; tuned receiver coils; Biomagnetics; Coils; Couplings; Feedback circuits; Magnetic resonance imaging; Negative feedback; Preamplifiers; Q factor; SQUIDs;
fLanguage
English
Journal_Title
Applied Superconductivity, IEEE Transactions on
Publisher
ieee
ISSN
1051-8223
Type
jour
DOI
10.1109/77.403276
Filename
403276
Link To Document