[10a-S301-1~10] 8.1 Plasma production and diagnostics

[10a-S301-10] Pressure Dependence of Atomic Oxygen Density and Lifetime in Sub-atmospheric Pressure Oxygen Discharge

〇Yusuke Nakagawa¹, Yuta Iwata¹, Fumiyoshi Tochikubo¹ (1.Tokyo Metro. Univ.)

Keywords:sub-atmospheric pressure plasma, atomic oxygen, laser spectroscopy

Atmospheric-pressure cold plasma (APCP) exhibits high chemical reactivity and valuable applicability to various targets including liquids and living materials. APCP produces high-density radicals, whereas the radical’s lifetime is short due to a frequent collisional deactivation. To address this issue, we focus on the plasma under sub-atmospheric pressure, which is slightly reduced pressure from the atmosphere. In this study, we measured the behavior of atomic oxygen (O) in sub-atmospheric pressure oxygen barrier discharge, using TALIF spectroscopy. The half-value period of atomic oxygen was extended by a factor of 10 by reducing pressure from 95 kPa to 20 kPa, whereas the peak O density at 20 kPa was 70% of that at 95 kPa. Therefore, radical flux in sub-atmospheric pressure plasma will be significantly higher than that in the atmospheric-pressure.