Sheath measurement in rf-discharge plasma with dust grains

The location of the sheath edge in a planar if-discharge has been determine d using test dust grains. The diagnostic technique is based on measurement of the equilibrium position of fine dust grains levitated above the powered electrode in an rf-discharge. Additionally two independent techniques base d on probe measurements and analysis of discharge optical emission have bee n used. All techniques provide values in good agreement. Using the resultin g value of sheath thickness the charge on dust particles in the sheath regi on has been estimated. (C) 2001 Elsevier Science B.V. All rights reserved.