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Low magnetic moment PIN diodes for high field MRI surface coils
Author(s) -
Voskoboynik Pavel,
Joos Ronald D.,
Doherty W. E.,
Goldfarb Ron B.
Publication year - 2006
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.2372216
Subject(s) - diode , diamagnetism , magnetic moment , pin diode , magnetic field , materials science , paramagnetism , magnetic resonance imaging , nuclear magnetic resonance , condensed matter physics , physics , optoelectronics , medicine , quantum mechanics , radiology
Positive‐intrinsic‐negative (PIN) silicon diodes are commonly used in magnetic resonance imaging (MRI) coils to perform active or passive blocking and detuning, or to disable circuit functions. However, diode packages with large magnetic moments are known to cause image artifacts in high field MRI systems. In this study, diode packages with low magnetic moment were designed by compensating components of ferromagnetic nickel and paramagnetic tungsten with diamagnetic silver. The new diodes have an initial positive susceptibility up to fields of 1 T and a negative susceptibility from 1 to 7 T . Their magnetic moments are one to two orders of magnitude smaller than those of standard diodes; moments as small as 20 nJ ∕ T at 7 T were achieved.