Intensified Video Optical Emission Spectroscopy (iVOES)---New Diagnostics for Studies of Transient Vacuum Arc Phenomena

Optical emission spectroscopy (OES) provides access to local arc plasma parameters, such as species densities and temperatures. The main drawback of conventional OES is restricted temporal resolution. The typical duration of a vacuum switching arc does not exceed 10 ms. Characteristic timescales for important physical phenomena within a high-current vacuum arc are, however, less than a microsecond. In order to overcome the shortcomings of conventional imaging OES, several advanced diagnostic methods have been developed. The most recent one is intensified video OES (iVOES). Capabilities and limitations of this new method with regard to investigations of switching vacuum arcs along with an application example are presented and discussed.