A Novel Method to Estimate and Control the Eddy Power Loss within the Cryostat: A Co-Simulation Approach to Tune Z-Gradient Array Coil

We propose a fast computational method based on a series of electromagnetic simulations to calculate a proper set of feeding currents for a z-gradient array coil that dynamically provides the best shield for its primary array coil. The net magnetic field generated by each array element is calculated, and the total average eddy power (energy) loss resulting from fast-switching stray fields inside the cryostat assembly is estimated and controlled. Two design scenarios with comparable performance criteria are offered for a 48-element z-gradient array coil. The accuracy of the estimated eddy power losses is compared with that of commercial software.