Heat transport of nitrogen in helium atmospheric pressure microplasma

Abstract

Stable DC atmospheric pressure normal glow discharges in ambient air were produced between the water surface and the metallic capillary coupled with influx of helium gas. Multiple independent repeated trials indicated that vibrational temperature of nitrogen rises from 3200 to 4622 K, and rotational temperature of nitrogen decreases from 1270 to 570 K as gas flux increasing from 20 to 80 sccm and discharge current decreasing from 11 to 3 mA. Furthermore, it was found that the vibrational degree of the nitrogen molecule has priority to gain energy than the rotational degree of nitrogen molecule in nonequilibrium helium microplasma.Comment: 4 pages, 5 figures, accepted by AP

Direct Current Atmospheric Pressure Microdischarge Generated between a Miniature Flow Helium Microjet and a Flowing Liquid Cathode

“…The T vib (N 2 ) and the T rot (N 2 ) were found to be depended on the flow rate of He and slightly decreased from 4 200 to 3 800 K and from 1 900 to 1 550 K, respectively. Values of the T vib and the T rot of N 2 were consistent with those reported in previous works related to various APGDs systems generated in contact with liquid cathodes . Quite different results were noted for the T vib (OH) and the T rot (OH).…”

“…Accordingly, APGD generated in the atmosphere of the ambient air between a miniature flow Ar jet and a bulky static liquid cathode (a NaCl solution) has been reported by Shirai et al These authors studied the emission characteristic of the microdischarge as a function of the discharge current and the temperature of a NaCl solution used as the liquid cathode, which both were found to be critical for discharge–liquid interactions. A similar construction of an APGD microsource generated between Ar or He microjets and bulky water cathodes was also investigated by Lu et al and Xu and Zhong . In both latter cases, microdischarges were examined due to N 2 rotational and vibrational temperatures.…”

Neutral gas temperature maps of the pin-to-plate argon micro discharge into the ambient air

“…E v ′ and E J ′ are vibrational state energy and rotational state energy. The more details can be found in references 20,22,24,25 . Fig.…”

“…Characteristics of micro plasmas, such as neutral gas temperature, electron temperature, electron density, ion density, electric field and so on, play an important role in physical and chemical processes [14][15][16] . There are many studies concerning the relationship between the bulk gas temperature and control parameters, for example, discharge current and gas flux, where the gas temperature is estimated using radiative transitions of diatomic molecules [17][18][19][20][21][22] . However, the temperature mentioned above is the mean temperature without spatial resolution.…”

Self-deformation in a direct current driven helium jet micro discharge

“…The helium gas flux controlled by a mass flux controller (MFC) is fixed to f = 10 sccm. The helium gas velocity v = 4f πd 2 at the exit is about 6.93 m/s and the Reynolds number Re = vρd µ is about 10.62, where ρ is the density of the helium gas and µ is the viscosity coefficient of the helium gas 16 . The initial gap distance between the exit of the capillary and the water surface is about 1 mm adjusted by a 3D mobile platform.…”