Re: Laser guided Tesla Coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FIFTYGUY@xxxxxxx 

In a message dated 2/15/07 9:28:11 P.M. Eastern Standard Time, 
tesla@xxxxxxxxxx writes:

>Yep, joules in nanosecond pulses or giga-watts can cause the air to
>"snap" ionize in front of some pulsed Nd-Yag lasers

    My issue with the whole concept of using lasers to pre-ionize a 
path for an electrical discharge is:

    You can't ionize the entire channel at once.
    Once the air is ionized, it is no longer optically transparent. 
If you ionize a spot of air near you, you can't ionize the spot of 
air in front of it because you can't "see" it.
    If you start by ionizing a spot of air closest to the target, 
then you'd have to ionize the spot just a little closer to you, then 
a spot a little closer, working your way back.
    For any "useful" distance, that's a lot of closely-spaced spots 
that have to be ionized. I have no idea, let's say the target is 100 
meters away, and each "spot" becomes an ionized patch the volume of 
1cc. That's 10,000 spots to ionize. The time scale would probably be 
what, 1/100th of a second before sufficient ion decay to make the 
spot useless (based on Tesla coil minimum effective BPS). So those 
10,000 ionized spots would have to happen at 1 Mhz.
    The only way I could see this happening is to sweep a continuous 
beam(or beams) from a source offset relative to the line-of-sight 
(line-of-electrical discharge). The focusing would have to be 
precise, yet continuous.
    A pretty tall order?
    And, as already pointed out, the energy required to ionize that 
path with a laser would better be spent on defeating the target 
directly with the laser!
    What kind of target can a lightning strike destroy that the 
super-high-powered laser (or a tank gun) can't?

-Phil LaBudde