Analysis of Collisional Sheath in an Argon dc Discharge

아르곤 직류방전의 충돌쉬스 구조해석

The electric fields of the sheath region in an argon do discharge were measured using a laser optogalvanic spectroscopy in a pressure range from 0.88 to 10 Torr, where collisions are significant in the sheath region. The sheath width is estimated as the position where the electric field becomes zero, and the pressure dependence of the measured sheath width was obtained to be $(pressure)^{-1/3}$. The measured electric fields agree well with one-dimensional simulation results but are slightly different from collisional sheath theory in the mobility limited region.