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.