Observations On Negative Ion Plasmas

Experimental observations that may have general interest are presented concerning a low micrometre size dust panicles pressure plasma (similar or equal to 10(-4) Torr) that consists of three components: positively charged ions, negatively charged ions and electrons (negative ion plasmas'). These observations include Langmuir probe characteristics and sheaths that are germane to such a plasma. Properties of plasma waves in a negative ion plasma such as phase velocity, dispersion and soliton propagation are described.