Sheath Properties in Two-Temperature Non-Maxwellian Electron Plasmas

The sheath criterion is modified for a plasma consisting of two-temperature nonextensively distributed electrons and positive ions with finite temperature. Using a two-fluid model, effects of the plasma parameters, such as temperature and density of positive ions and temperature ratio and degree of nonextensivity of both electron species on the allowable velocity of ions at the sheath edge (u
_0i
) are investigated. The results show that u
_0i
depends on temperature and density of ions and electron species as well as degree of nonextensivity of cold and hot electrons (q
_c
and q
_h
). Using our derived sheath criterion, the effects of temperature of ions and temperature and density of hot electrons on the properties of the sheath region of a superthermal two-temperature electrons plasma are studied numerically.