It is well known that Magnetic Resonant Imaging (MRI) devices radiate strong noise. Because a detecting coil disk in which a strong pulsive current flows is placed in a strong static magnetic field, the Lorentz's forces act on the coil and excite the bending vibration of the coil. Thus we have tried to precisely estimate the frequency spectrum of radiating sound power based on modal analysis, forced vibration analysis and sound field analysys, and to propose structural optimzation so as to reduce sound power. A finite element model of a detecting coil disk as a composite of GFRP and cupper wires was made and analyzed. The sound power was theoretically estimated and experimentally measured. The relation between number of fixed bolts and the radiating sound power was revealed.
*We have collaborated with GE Yokogawa Medical Systems Co. Ltd. for this research.
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