Saturated Absorption Spectra of Metastable Argon Atoms in a Thin Discharge Cell

Abstract

Saturated absorption spectra of the 1s 3 –2p 2 (Paschen notation) line of metastable argon (Ar * ) atoms in a 1 mm thick glow discharge cell have been observed at room temperature. We examined the pressure dependence of the spectra from 0.025 to 0.5 torr. The profiles of the spectra were compared with the velocity-changing collision kernels of the Ar * (1s 3 )–Ar collisions. The results suggest that the saturated absorption spectroscopy with the thin cell is useful to detect collision kernels of metastable atoms.