Large amplitude wakefield in an ion wave regime excited by short microwave pulse

When a short microwave pulse of the order of an ion wave period is irradiated in a nonuniform unmagnetized plasma, non-linear large amplitude waves (δn/n0≅40%) in an ion wave regime have been observed. The observed large amplitude waves can be interpreted by the model based on the Mach-cone structure induced by the supersonic ion bunch accelerated by a wave field at the resonance layer. Before growing the large amplitude ion wave, hot ion beam with the energy (≅25 eV) was observed by a tiny Faraday cup. The energy of ion beam is good agreement of predicted by the Mach-cone theory. copyright 1996 American Institute of Physics