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Sci‐Fri AM General‐01: X‐Ray Tube Induction Motor Performance in a 1.5 T MRI Fringe Field
Author(s) -
Bracken J,
Rowlands J
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 - 10.1118/1.2244666
Subject(s) - anode , x ray tube , scanner , rotating magnetic field , rotation (mathematics) , magnetic field , physics , electric motor , materials science , tube (container) , optics , nuclear magnetic resonance , electrical engineering , engineering , mathematics , composite material , geometry , electrode , quantum mechanics
We assessed the performance of the induction motor of a rotating‐anode x‐ray tube in the magnetic fringe field of a clinical MRI scanner. A standard rotating‐anode x‐ray tube insert was placed into the fringe field of a 1.5 T unshielded research MRI scanner. The induction motor in the x‐ray tube was aligned so that the magnetic field lines were in the plane of its stator core. The induction motor of the x‐ray tube was placed in magnetic fields ranging from 0 to 500 G. The magnetic fields were measured with a Model 4048 Gauss meter. The rotation speed of the anode was measured using a strobe light. The power consumed by the motor during operation in the fringe field was measured separately using a PLM‐1 power meter. The anode rotation speed dropped from 3437 +/− 6.8 rpm to 2744 +/− 5.3 rpm when the magnetic fringe field was increased from 0 to 400 G. The average power consumed by the motor increased from 70.5 +/− 0.4 W to 78.2 +/− 0.1 W when the fringe field was increased from 0 to 500 G. This work indicates the feasibility of safely operating an x‐ray tube induction motor in the fringe field of an MRI scanner. Power consumption did not significantly increase and anode rotation speed did not fall below 3000 rpm until a fringe field exceeding 300 G was applied.