Mechanically Adjustable Shielded Insert Gradient for Experimental Evaluation of Construction Tolerances

Dustin Wesley Haw¹, Brain Dalrymple¹, Frank Van Sas¹, Timothy James Scholl¹, Blaine Alexander Chronik¹

Virtually all applications in MR require the rapid switching of gradient fields within the scanner, and many emerging applications take advantage of rapidly switched shim coils; eddy-currents generated in the system are therefore a constant challenge. The construction tolerances required for these shielded systems are not well known. Our goal is to examine the eddy-currents generated by driving a special shielded insert gradient coil of our own design. We present initial results with this test system for the impedance of the shielded gradient insert as a function of shield positioning error, both inside and outside an idealized scanner bore.