Production of negative ion plasmas in a Q machine

Abstract

A negative ion plasma is produced by introducing a small amount of SF6 gas into a low-temperature ( approximately=0.2 eV) potassium plasma produced in a Q machine. The density ratio of negative to positive ions is continuously varied in the range up to more than 0.9999, where there appears a remarkable decrease in electron shielding for potential variations, yielding a clear effect on plasma collective phenomena. By introducing fullerene (C60)particles into the Q-machine plasma, we can produce a plasma including large negative C60 ions. This ultrafine particle plasma might prove very attractive in fields of materials science.