Discharge Modes Suggested by Emission Spectra of Nitrogen Dielectric Barrier Discharge with Wire-Cylinder Electrodes

Abstract

In this paper, nitrogen dielectric barrier discharge (DBD) plasma was generated in a quartz tube with coaxial wire-cylinder electrodes at atmospheric pressure. By varying the nitrogen gas flow (FN) in the range of 0-1 m 3 /h, the plasma optical emission spectra (OES) were measured and studied. The vibration (T vib) and rotation temperature (Trot) of nitrogen were obtained, by fitting the rovibronic bands of N2(C 3 Πu − B 3 Πg, 0-1), and by the Boltzmann plot method for purposes of comparison. T vib increased up to 2481 K with increasing nitrogen flow till 0.2 m 3 /h, and then decreased with further increasing FN , while Trot decreased monotonously and approached to ∼350 K for FN ≥ 0.6 m 3 /h. The intensity of N2(C 3 Πu − B 3 Πg, 0-0, 1-0, 0-3) and N + 2 (B 2 Σ + u − X 2 Σ + g , 0-0) exhibited similar evolution with increasing FN to those of the T vib and Trot, respectively. The discharge photos revealed that the discharge filaments gradually decreased with increasing FN , and eventually disappeared, which implied that a discharge mode transition emerged with increasing FN. The possible mechanism for the discharge mode transition is studied in detail according to the vibration (T vib) and rotation temperature (Trot) of nitrogen.

A double‐mode planar argon plume produced by varying the distance from an atmospheric pressure plasma jet

“…Moreover, T vib can be estimated via Boltzmann plot from N 2 (C 3 Π u →B 3 Π g ) [58]. The corresponding parameters are summarised in Table 2 [59], where $${\lambda }_{{\nu }^{\prime }{\nu }^{{\prime\prime}}}$$ and $${A}_{{\nu }^{\prime }{\nu }^{{\prime\prime}}}$$ are the wavelength and the transition probability for the upper ( ν ′) and lower ( ν ″) vibrational states respectively.…”

“…Considering the high E h and the weak field in a filament, T exc in the filamentary mode is much lower than that in the streamer mode. Moreover, T vib can be estimated via Boltzmann plot from N 2 (C 3 Π u →B 3 Π g ) [58]. The corresponding parameters are summarised in Table 2 [59], where λ ν 0 ν 00 and A ν 0 ν 00 are the wavelength and the transition probability for the upper (ν 0 ) and lower (ν″) vibrational states respectively.…”

Discharge aspects of a snake‐like plasma plume generated by an atmospheric pressure plasma jet with variable argon flow rate

“…Six lines, including 380.4 and 405.9 nm ( ν ′ = 0, E ν′ = 0.126 eV), 375.5 and 399.8 nm ( ν ′ = 1, E ν′ = 0.374 eV), 371.0 and 394.3 nm (ν′ = 2, E ν′ = 0.617 eV), are selected to calculate T vib . [ 73,74 ] As a result, each E ν′ corresponds to double values of $$\mathrm{ln}({I}_{{{\rm{\nu }}}^{\text{'}}{{\rm{\nu }}}^{^{\prime\prime} }}/{v}_{{{\rm{\nu }}}^{\text{'}}{{\rm{\nu }}}^{^{\prime\prime} }}{A}_{{{\rm{\nu }}}^{\text{'}}{{\rm{\nu }}}^{^{\prime\prime} }})$$. It is clear in Figure 10b that T vib decreases with increasing Q , which is similar to the variation trend of T e and n e (Figure 9c,d).…”

“…Six lines, including 380.4 and 405.9 nm (ν′ = 0, E ν′ = 0.126 eV), 375.5 and 399.8 nm (ν′ = 1, E ν′ = 0.374 eV), 371.0 and 394.3 nm (ν′ = 2, E ν′ = 0.617 eV), are selected to calculate T vib . [73,74] As a result, each E ν′ corresponds to double values of I v A ln( / ) ν′ν″ ν′ν″ ν′ν″ . It is clear in Figure 10b that T vib decreases with increasing Q, which is similar to the variation trend of T e and n e (Figure 9c,d).…”

Generation of reactive atomic species of positive pulsed corona discharges in wetted atmospheric flows of nitrogen and oxygen

“…Recently, there have also been a number of studies on the production and concentration of OH and other active species [17][18][19][20][21][22][23]. Liao et al [17] investigated the formation of hydroxyl radicals in dielectric barrier discharge (DBD) during the decomposition of toluene and developed a new method to measure hydroxyl radicals with high-performance liquid chromatography.…”