Factors affecting the UV emission from pulsed surface discharges

The emission properties of pulsed electrical discharges propagating across the surfaces of PET, PP, PTFE, UPVC, and PVDF in various gases have been investigated. The optical spectra from the discharges have been recorded over the 200-500 nm bandwidth and the effect of the interaction between the pulsed discharge and the substrate material studied. The gases used were air, argon, and SF6 at pressures in the range 0.1-1 bar. In comparison to the other gases, SF6 was found to produce the most intense continuum and line emission within the 200-300 nm spectral region. The substrate material was found to affect both the intensity of continuum spectra and the content of the discrete line spectra. When PTFE was employed, the continuum spectra was more intense compared to that of the other materials. In contrast, the use of PVC resulted in a considerable modification to the composition of the discrete line spectra.