title: Anomalously high near-wall sheath potential drop in a plasma with nonlocal fast electrons.
abstract: It is demonstrated for the first time that the presence of a small number of fast, nonlocal electrons can dramatically change the thickness of and electric field in the near-wall sheath. Even if the density of the nonlocal fast group, , is much less than the density of the bulk electrons, n(b) (n(f) approximately 10(-5) n(b)), the near-wall potential can increase dramatically resulting in a comparable increase in the sheath thickness. Because of this low fractional density, the average energy (electron temperature ) of all electrons is little changed from that of the bulk, yet the near-wall potential drop can increase to tens of T(e)/e. More importantly, due to the nonlocal nature of this group of electrons, the near-wall sheath potential is found to be independent of and is determined only by the energy of the fast group.
authors.affiliation: UES, INC., 4401 Dayton-Xenia Road, Dayton, Ohio 45432, USA.
authors.forename: V I
authors.initials: VI
authors.lastname: Demidov
authors.forename: C A
authors.initials: CA
authors.lastname: Dejoseph
authors.forename: A A
authors.initials: AA
authors.lastname: Kudryavtsev