  A cylindrical system is proposed that will store magnetic energy in a
localized azimuthal field that can then be quickly released on Alfvenic
timescales, accompanied by the formation of a flowing Z-pinch plasma. The
magnetized plasma is MHD in character and will have unilateral axial momentum
with Alfvenic speeds. Conventional plasma gun injectors (Marshall type) have a
limited parameter space of operation. The "magnetic spring" momentum injector
differs from Marshall guns in that it has an already stored strong magnetic
field before release. The resulting parameter space is much broader. There are
possible applications to momentum injectors for fusion and to plasma and rail
guns.
