AN INVESTIGATION OF DIRECTED SUPPORT GAS-FLOWS FOR THE IMPROVEMENT OF SAMPLING EFFICIENCY IN GLOW-DISCHARGES

The use of directed support gas flows for the reduction in re-deposition of sputtered atoms in glow discharges has been investigated. In addition, various surface features of the bum spot obtained with a laboratory constructed jet-assisted glow discharge source have been studied using scanning electron microscopy and energy-dispersive X-ray analysis. The use of jets reduces re-deposition by a factor of three relative to static discharges improving the sampling efficiency for glow discharges, although significant redeposition occurs along the edge of the burn spot. It was also found that sample preparation can cause a higher incidence of bum spot cones and other surface structures which can reduce depth profiling resolution.