A high power driving and selection field coil for an open MPI scanner

Three Litz wires have been used in parallel in order to decrease the layer to layer voltage down to 4 kV and the coil voltage down to 8 kV. A two millimeter thick epoxy plate has been glued between each layer, in order to prevent any electrical breakdown between the layers. A special epoxy has been used to minimize the inner temperature of the coil, which reached 180°C with a dissipated power of 5.2 kW. The use of parallel Litz wire leads to currents having different phase angle in every wire which has to be corrected.