Dielectric Barrier Discharge in atmospheric helium under different Background Air Pressure

The Penning ionization in atmospheric helium Dielectric Barrier Discharges (DBD) with air impurity was investigated. Discharge inception voltage and emission spectra were measured under Background Air Pressures (BAP) from 0.8 Pa to 1000 Pa. Results show that in a range of BAP from 0.8 Pa to 190 Pa, discharge inception voltage decrease obviously and the intensity of the 391.4 nm line increase with the BAP. When BAP exceeds 190 Pa, discharge inception voltage increases linearly obviously, and intensity of the 391.4 nm line gradually drops to lower value with the BAP, even about a zero value at last. Emission spectra of helium decrease with the BAP. Physical processes analysis indicates both discharge inception voltage and emission spectra illustrate that Penning ionization due to helium metastables and N₂ varies with the BAP.