TY - PAT AB - An electromagnet assembly comprises a first pair of substantially co-planar coils wound in opposite senses to each other. It further comprises a second pair of co-planar coils also wound in opposite senses to each other. The coil pairs are arranged substantially parallel to, and spaced apart from, each other. In use, the field shape and direction produced by the first coil pair are substantially mirrored by those produced by the second coil pair. AU - McGinley,JVM AU - Young,IR PY - 2015/// TI - Electromagnet Assembly ER -