OH Radicals Distribution in a Nanosecond Pulsed Atmospheric Pressure Plasma Jet

Using the laser-induced fluorescence technique (LIF), the distribution of OH radicals in a nanosecond pulsed room-temperature atmospheric plasma jet was studied in this paper. The OH LIF signals are much stronger on both ends than at the center after the first discharge pulse, which means donut-shaped LIF signals. As the number of discharge pulses increased, the donut-shaped LIF signals fade away and the intensity of OH LIF signals is increased significantly. After about 11 discharge pulses (at 1251 μs), the OH LIF intensity reaches to a saturation value, which is over ten times larger than that generated during the first discharge pulse at 1 μs.