Synchronous Collection And Analysis Of Optical Spectrum And V-I Signal From Nanosecond Pulse-DBD

Atmospheric pressure dielectric barrier discharge pulse discharge because of its easy to implement the environment and to produce high density plasma has been widely used in medical, material handling, environmental governance, and other fields. This paper aimed at atmospheric pressure dielectric barrier discharge pulse spectrum acquisition mode and discharge V-I characteristic discussed and studied.This paper used microcontroller to control the discharge pulse power and spectrometer collect spectrum, had realized every discharge spectrum couid be collected. This acquisition method could be used to reach the previous way of collecting spectral could not acquire the effects of single discharge accurately and synchronouslyThe experiment adopted the flow rate of 1000 SCCM argon as carrier gas, the voltage was 30.8 kV, voltage rose time of 130 ns, pulse width was about 350 ns, and collected single discharge voltage and current. Using dielectric barrier discharge equivalent circuit and voltage current were collected, by comparing the gap voltage and electrode current in not discharged and discharged, identified the pulse gas avalanche happened only during the period of about 20 ns time, and then happened RLC oscillation phenomena with the residual charge. By comparing the size of the pulse voltage was different, found that the time of the steep fall in the air gap voltage delayed, with the pulse voltage size increased 20 kV, time delayed around 230 ns. With the size of pulse voltage phase unchanged, changing the gas flow of DBD gap, found that the time of discharge point didn’t change. That showed in this experimental conditions, the gas breakdown time was mainly determined by pulse voltage, the influence of argon gas concentration was not big.This paper compared the spectrum that collected adjacent wavelength of 763.498 nm and 772.332 nm characteristic peaks by spectrograph,With the condition of the pulse voltage amplitude was 30.8 kV, pulse width was 350 ns, carrier gas flow was 1000 sccm, collected 10 consecutive discharge spectral intensity, spectral intensity fluctuation changed little. With the flow of argon gas unchanged, in the standard atmospheric pressure, spectral intensity of pulsed dielectric barrier discharge enhanced with increasing of pulse voltage. The calculated electron excitation temperature fell, the excitation temperature fluctuations became smaller. This showed that with increasing applied voltage, the electron excitation temperature became more stable. Experiment was also observed in the pulse voltage phase at the same time, argon gas concentration was low, spectral intensity with the increase of argon gas concentration increased faster, when argon gas concentration reached a certain value, enhanced slowly with argon gas concentration increased again, electron excitation temperature also fell. Finally through comparing the argon gas concentration change and the change of the voltage to the spectral intensity influence, it was concluded that the change of spectral intensity under this experimental condition mainly depended on the change of the voltage, also related to the concentration of the argon discharge environment. By comparing the wavelength of 763.498 nm and 772.332 nm spectral intensity with electron density or the ion density relationship, it was concluded that when argon gas concentration was constant, the relationship was linear proportional between spectral intensity with electron density or the ion density, the voltage pulse amplitude kept steady, the relationship was no longer linear proportional between spectral intensity and electron density or the ion density. Using the emission spectrometry method measured electron temperature, calculated the electron excitation temperature changed from 0.16 eV to 0.47eV during whole experiment process.