5-27-04 Tesla List Q & A:
Q.  The cables do not appear to be very large in diameter --- perhaps an inch or two at best.  With that small radius and diameter, why don't they emit tremendous corona?

A.  The fundamental reason is because the wires are essentially straight.  Cylindrical conductors don't follow the same rule of spheres, where 30 kV per cm of radius is enough to create corona.  If you try to calculate the electric field at the surface of a long wire that is at a given potential, the result is that that if the wire has infinite length and is really straight, the breakdown voltage is infinite. But real wires are always somewhat curved by gravity.  Antonio CQ.

Antonio,  This has interesting implications for lifters which have a 'corona wire'.  I have observed that the corona is only really evident at the terminations of the balsa uprights or where there are kinks in the wire.  They also don't arc over in the mid section of the wire unless it is too loose and flaps around too much.  I would expect that maximizing corona
would improve lifting efficiency. It would be nice to have a wire with conductive projections like fluff than a smooth straight albeit thin one.  Peter  http://tesladownunder.iinet.net.au/.