High charge states metal ion beam based on vacuum spark discharge

Summary form only given. For wide used vacuum arc ion sources¹ extracted ion beam contains multiply charged metal ions with charge states often from 1+ to 3+ and rarely to 4+ and 5+. Succeeding elevation of metal ion charge states in vacuum discharge plasma is interesting problem for ion beams physics, because for practical using it leads to proportional increasing of ion beam energy with the same accelerating voltage. It is important thing due the cost of an ion source with an ion energy from tens to hundreds of keV as well as the X-ray flow have an approximately quadratic dependence on accelerating voltage, all other parameters being equal. Hence, the optimal way of increasing the ion beam energy is not by increasing the accelerating voltage but by increasing the mean ion charge state.The metal ion charge state elevation could be provided by using in vacuum arc ion source vacuum spark discharge, which is initial stage of vacuum arc2. Since the voltage between anode and cathode remains high, compare with the vacuum arc high charge states of metal ion in discharge plasma was generated and than extracted in ion beam. The using of discharge with current up to 10 kA and pulse duration less 10 microseconds provides generation of ion beams with current of several amperes with pulse repetition rate up to 5 pps. The higher ion charge states for heavy ions (bismuth) were up to 12+ and mean ion charge state was more 8+. Physics and techniques of elevation of metal ion charge state in spark discharge are discussed.