Photo corona discharge

Figure 11-69. Photo of the 10-kW pulsed corona discharge (organized in the water-spray configuration) through a window of the Mobile Environmental Laboratory.

Currently there are four commercial companies offering handheld and portable gas phase time-of-flight ion mobility spectrometers, with drift tubes shorter than 5 cm Smiths Detection, Bruker-Daltonics, GE-Interlogix, and G.A.S. Gesellschaft fiir analytische Sensorsysteme mbH. Table 1 presents their respective instruments and their major applications. These instruments generally use an applied electric field of around 250 Vcm , and they operate at either ambient or elevated temperature, and at atmospheric pressure. The samples are ionized by radioactive nickel-63 source mostly, but also by corona discharge and photo-ionization source. 

Surfaces of polymers are the locations which are directly exposed to the environment (e.g. sun, oxygen, moisture, pollutants etc.)- Degradation such as oxidation, photolysis, photo-oxidation also high energy degradation, corona-discharges, and other intended types of degradation, will Initially be at a maximum at surfaces. 

---