Table 2.

Summary of the NPT conditions used in this work. In the Ω and the γ modes, helium is injected through the annular gap and O₂ is injected within the high-voltage electrode. In the jet mode, helium is injected within the high-voltage electrode and ambient air is left to fill the annular gap freely. In the γ mode, pulse modulation was used to maintain gas temperature near room temperature.

Conditions	Discharge Mode	Applied Power	Treatment Time	Helium Flowrate	O2 Flowrate
Ω	Ω mode	10 W	4 min	4300 mL min−1	0 mL min−1
Ω + O2	Ω mode	10 W	4 min	4300 mL min−1	2 mL min−1
γ	γ mode	35 W (100 Hz@20%)	2 min	4300 mL min−1	0 mL min−1
γ + O2	γ mode	35 W (100 Hz@20%)	2 min	4300 mL min−1	2 mL min−1
Jet	Jet mode	35 W	10 to 120 s	600 mL min−1	0 mL min−1