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| Experimental study of plasma breakdown | |
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Plasma breakdown is the process that occurs when a voltage is applied across an electrode gap. The neutral gas in the gap becomes ionized and an electrical current is established. Examples of breakdown can be found both in nature, for example lightning, and in man-made devices such as discharge lamps and air purification systems |
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Figure 1: Example of plasma breakdown |
The aim of our research is to experimentally study the phenomenon of plasma breakdown.
During breakdown, an ionization front crosses the electrode gap with velocities of 106 ~ 108 m/s. This results in time scales for the entire breakdown process of 10-10 ~ 10-8 s. Up to now, it has been impossible to obtain detailed information about the traveling ionization front, due to its high velocity. The goal of our research is to study the breakdown process on a sub-nanosecond time scale. More specifically, the aim is to study the electric field distributions and electron properties of the ionization front crossing the discharge using in-situ laser diagnostic techniques
The results obtained in this study will provide better understanding of the fundamental nature of breakdown and will enable better models of specific plasma devices to be developed. The new information obtained in these studies could lead to technological breakthroughs in several application areas. |
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Measurements of electric fields during breakdown are done by means of Stark spectroscopy. To obtain sub-nanosecond resolution, a temporal pulse compression system, based on Stimulated Brillouin Scattering (SBS) is applied. |
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| The research is performed in collaboration with Mark Bowden at the Open University in Milton Keynes (UK). | |
