Physical properties of plasma streamers produced on water surface

Validation of the local thermodynamic equilibrium at a local current concentration area of positive pulsed surface discharge plasma on water

“…Therefore, the variation of R(t) has a significant effect on the FWHM of the current because of the constant value of C. (C-B), second positive system, and OH (A-X), which are well observed in the other studies. 16,22,23) On the other hand, the ionic spectra N + which have not been observed from the surface discharge on water were observed under the water depth of 2 mm, as shown in Fig. 6 (a).…”

“…The discharge developing along the water surface is a non-LTE state. 22) Under the 2 mm water depth, the N + was detected and the resulting electron temperature was above 30000 K (see Fig. 8).…”

“…P. Hoffer et al reported the rotational and vibrational temperature of the surface discharge on water estimated by N2 2 nd positive system as a function of distance from the needle electrode. 22) According to the literature, the significant difference between vibrational and rotational temperatures appears; the vibrational temperature is approximately 3000 K and the rotational temperature is approximately 750 K. Consequently, the plasma condition of the pulsed surface discharge changes from place to place. Figure 11 shows a rough sketch of the pulsed surface discharge on water with supposed discharge phase.…”