Ignition of a nanosecond-pulsed near atmospheric pressure discharge in a narrow gap

Abstract

To cite this version:Sarah Müller, Dirk Luggenhölscher, Uwe Czarnetzki. Ignition of a nanosecond-pulsed near atmospheric pressure discharge in a narrow gap.

Kinetic simulation of a nanosecond-pulsed hydrogen microdischarge

“…[1][2][3] Despite the small size of these devices, state-ofthe-art diagnostics methods have been applied to reveal details of discharge operation. [4][5][6][7][8][9][10][11] In microdischarges excited by nanosecond pulses, transient electron dynamics takes place on a nano-or subnanosecond time scale. In combination with the small discharge dimensions, this makes numerical and experimental investigations particularly challenging.…”

“…The electrode gap is L = 1.2 mm and the gas pressure is 230 mbar. Previous experimental studies on this system using various diagnostics 10 have revealed a complex spatial and temporal dynamics of different parameters, such as the optical emission, electric field, current, and electron density. The present letter intends to provide insight into these observations via numerical simulations.…”

“…The voltage waveform applied to the cathode is taken from the experimental recording. 10 Figure 1͑a͒ shows the applied voltage waveform. The voltage peak centered around 26 ns has a width of about 8 ns.…”

“…These data, as well as the spectrally integrated and spectrally resolved light emission patterns ͑excitation rates͒ are compared next with the respective experimental results. 10 Figure 2͑a͒ shows the total electron impact excitation rate ͑excluding rotational and vibrational excitation͒, panels ͑b͒ and ͑c͒, respectively, show the electron impact excitation rates of the Fulcher ␣ ͑d 3 ⌸ u − → a 3 ⌺ g + ͒ band ͑having a threshold energy th = 14.0 eV͒ and the Balmer alpha ͑H ␣ ͒ transition ͑resulting from dissociative excitation, th = 16.6 eV͒. Figures 2͑d͒-2͑f͒ At the beginning of the voltage pulse ͑10 nsϽ t Ͻ 23 ns͒, there is only little space charge inside the gap, the electric field in the discharge center follows the driving voltage ͓Fig.…”

Formation of carbon nanoparticle using Ar+CH4high pressure nanosecond discharges

“…The inner diameter and length of the reactor were 58 mm and 77 mm, respectively. Two pieces of stainless steel electrode of 15 mm in diameter were placed at the center of the reactor as shown in figure 1 [30,31]. The gap between the powered electrode and the grounded electrode was 0.2 or 0.5 mm.…”