Negatively charged dust particles are expected to modify the local sheath p
otential where they are in equilibrium. In the conditions of a hot cathode
discharge, sheath profiles are deduced from the measurement of ion drift ve
locities, with dust particles in suspension and without. In the unperturbed
potential profile, the surface potential of an isolated dust particle, its
charge, and its potential energy can be estimated as a function of the pos
ition in the sheath. In the presence of dust particles, an average increase
of the ion drift velocity is measured showing a modification of the local
sheath profile. This experimental result suggests that the dust particle ch
arge due to the plasma particle fluxes in the sheath, modifies in turn the
local plasma particle distributions. (C) 2000 American Institute of Physics
. [S1070-664X(00)04911-9].