Homopolar generators for electric guns

Low voltage homopolar generators combined with magnetic energy storage inductors were used to power several early experimental railguns. Over the last 10 years this arrangement has fallen into disfavor for future high-energy railgun systems compared with multipole AC generators, largely because of the need for an opening switch to both transfer high current and open against voltages of a few kV. Basic features of homopolar generators are examined and factors relating to their potential for future electrothermalchemical (ETC) gun systems are considered briefly. The energy and current requirements for such guns are substantially less than for high energy railguns, so that homopolar generators (HPGs) may prove feasible.