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Publication Citation: Low Magnetic Moment PIN Diodes for High Field MRI Surface Coils

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Author(s): Pavel Voskoboynik; Ronald D. Joos; W E. Doherty; Ronald B. Goldfarb;
Title: Low Magnetic Moment PIN Diodes for High Field MRI Surface Coils
Published: November 08, 2006
Abstract: 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.
Citation: Medical Physics
Volume: 33
Issue: 12
Pages: pp. 4499 - 4501
Keywords: image artifacts,magnetic moment,magnetic resonance imaging,magnetic susceptibility,positive-intrinsic-negative diodes
Research Areas: Electromagnetics
PDF version: PDF Document Click here to retrieve PDF version of paper (69KB)