Improved double planar probe data analysis technique

Abstract

Plasma electron number density and ion number density in a dc multidipole weakly collisional Ar plasma are measured with a single planar Langmuir probe and a double planar probe, respectively. A factor of two discrepancy between the two density measurements is resolved by applying Sheridan's empirical formula [T. E. Sheridan, Phys. Plasmas 7, 3084 (2000)] for sheath expansion to the double probe data.