Early Streamer Emission (ESE)Indelec2015-12-08T15:49:46+00:00
EARLY STREAMER EMISSION TECHNOLOGY
When lightning strikes, an electrical field is always created at ground level and this increases in intensity as the «downward leader» approaches. Once this reaches a certain level – between 50 and 100 kV/m – the Corona effect, which develops naturally at the top of any high structure, allows discharges – known as upward leaders – to rise toward the cloud
The position of the ionized path which will allow the lightning current to pass is determined by where the upward leader comes into contact with the first downward leader from the cloud. The sooner the rising discharge (upward leader) leaves the lightning rod to move toward the cloud, the sooner it will move closer to the downward leader and the greater the chances of the two making contact before other rising discharges from nearby high points.
It can be seen, then, that it is the start point of the first upward leader which determines the point of impact of the lightning on the ground. An early streamer emission lightning rod is designed to provide optimal conditions for the formation of this rising discharge.
For this the following conditions are necessary:
The presence of primary electrons at the top of the rod : these electrons, given off in the form of plasma, encourage the start-up of the rising discharge.
Ionized plasma being formed at the right moment when lightning is about to strike, in other words, in phase with the rising electric field at ground level.