A system and method for decreasing partial discharge between adjacent conductive plates (94, 96, 98) includes suspending a plurality of particles (100) in the space (92) between adjacent plates (94, 96, 98) of a magnetic coil (70). The plurality of particles (100) are generally uniformly dispersed in the space (92) and allow for increased partial discharge inception voltages. Such a construction allows the coil (70) to operate at elevated driving voltages with reduced partial discharge between adjacent plates (94, 96, 98).