The spatially resolved measurements of the atomic densities in argon Paschen 1s levels by OES in a capacitively coupled plasma

Spatially resolved atomic densities of argon 1s levels in a capacitively coupled plasma are measured by using an OES branching fraction method with the mono-directional escape factor. Different spatial profiles of the densities of the metastable and resonance levels are observed. The resonance levels increase more drastically than the metastable levels with the distance from the power electrode in the sheath, while in the bulk plasma, both resonance and metastable levels are more uniform. The relationship between the distribution of the electron density and those of the metastable and the resonance levels is also discussed.