A time-dependent model containing several new features has been developed for treating the breakdown of water under nanosecond pulsed conditions. It is argued that the traditional mechanisms such as bubble formation and thermal heating no longer apply. Instead, the mechanism of breakdown will be dictated by the surface electric field behavior and subsequent injection of electrons at the interface. Thus, the interface layer and electrode conditions will begin to be far more important than the bulk liquid properties in determining breakdown and hold-off voltage levels. It is shown that very strong electric field enhancements can occur due to the collective orientation of dipoles near the interface. Under high voltage conditions, the injected electrons are assumed to have relatively long lifetimes due to a continuous replenishment of energy from the external field. The simulations show a breakdown within about 200 ns for an applied pulse of 20 kV for a 200 μm water-filled switch. The predictions are in keeping with recent experimental observations by our group.
|Number of pages||4|
|State||Published - 2003|
|Event||14th IEEE International Pulsed Power Conference - Dallas, TX, United States|
Duration: Jun 15 2003 → Jun 18 2003
|Conference||14th IEEE International Pulsed Power Conference|
|Period||06/15/03 → 06/18/03|