Journal of Applied Physics
We present a new approach to measure population densities of Ar I metastable and resonant excited states in low temperature Ar plasmas at pressures higher than 1 Torr. This approach combines the time resolved laser induced fluorescence technique with the kinetic model of Ar. The kinetic model of Ar is based on calculating the population rates of metastable and resonant levels by including contributions from the processes that affect population densities of Ar I excited states. In particular, we included collisional quenching processes between atoms in the ground state and excited states, since we are investigating plasma at higher pressures. We also determined time resolved population densities of Ar I 2 p excited states by employing optical emission spectroscopy technique. Time resolved Ar I excited state populations are presented for the case of the post-discharge of the supersonic flowing microwave discharge at pressures of 1.7 and 2.3 Torr. The experimental set-up consists of a pulsed tunable dye laser operating in the near infrared region and a cylindrical resonance cavity operating in TE111 mode at 2.45 GHz. Results show that time resolved population densities of Ar I metastable and resonant states oscillate with twice the frequency of the discharge.
Original Publication Citation
Nikolic, M., Newton, J., Sukenik, C.I., Vuskovic, L., & Popovic, S. (2015). Measurements of population densities of metastable and resonant levels of argon using laser induced fluorescence. Journal of Applied Physics, 117(2), 1-8. doi: 10.1063/1.4905611
Nikolic, M.; Newton, J.; Sukenik, C. I.; Vuskovic, L.; and Popovic, S., "Measurements of Population Densities of Metastable and Resonant Levels of Argon Using Laser Induced Fluorescence" (2015). Physics Faculty Publications. 2.