Figure 5
Excitation temperature and oxygen atom density at different additive oxygen flows in Type 2.
A Boltzmann plot method was used to estimate the excitation temperature: (A) Boltzmann plot of atomic helium lines (447, 501, 587, 667, 706 and 728 nm) for the additive oxygen flow rate of 400 SCCM. Variations of (B) the excitation temperature and (C) estimated atomic oxygen density via actinometry as a function of the additive oxygen flow rate. The dotted line indicates the expected estimates when the generation of excited oxygen atom via the collisional reactions involving oxygen metastables and excited oxygen molecules is considered.
