Measurements of spatial and temporal sheath evolution inside tubular material for inner surface ion implantation

Tubular target of aluminum (inner radius=5 cm, length=15 cm) was immersed in a nitrogen plasma with plasma densities of 6.8X10(9)-5X10(10) cm(-3) and biased negatively (10-30 kV). A langmuir probe was used to detect the propagating sheath edge. A comparison of experiment measurements and numerical calculations of temporal and spatial sheath evolution is presented. Experiment measurements of sheath edge position were in good agreement with those determined by numerical calculations. (C) 1996 American Vacuum Society.