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Re: HV + laser beams
Subject: Re: HV + laser beams
Date: Wed, 21 May 1997 05:26:48 +0500
From: "Alfred A. Skrocki" <alfred.skrocki-at-cybernetworking-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
On Mon, 19 May 1997 19:52:29 -0800 Greg Leyh
<lod-at-pacbell-dot-net> wrote;
> > > Five MILLI-watts?! No one gets it here! Try 5 MegaWatts! Now were
> > > talking!...
> >
> > David, I don't think that uch power is required. I remember hearing
> > back around 1973 that some students at MIT used a U.V. laser of a few
> > watts (Nitrogen laser I think) to conduct the output of a small Tesla
> > coil several hundred feet to an isolated terminal and draw several
> > inches of spark from the isolated terminal to ground.
>
> Several hundred feet? I am skeptical, as the laser needs to have an
> intensity sufficient to ionize the air along the entire light path.
> A 100kW pulsed laser can ionize the air if focussed to a point, but
> tens of megawatts are required in order to ionize an appreciable
> linear path to the point of conduction. Even though a 10MW pulsed
> laser is relatively available (large table top, <1M$), I doubt that
> even 10MW pulsed could ionize more than a 10 foot path thru the air.
Hi Greg, what you have to realize about Nitrogen lasers is they
operate in pulsed mode and even though their average power may be
only a few watts the pulsed beam can approach the megawatt range.
It's as if you charged a capacitor with 1 watt hour of power and
discharged it in one millionth of a second, that would effectively
be 36 billon watts but only for one millionth of a second. In the
case on the UV laser even though the path is ionized in fractions of
a second it takes much longer for the path to stop conducting so for
all intents and purpose it may as well be a continous conducting
path.
Sincerely
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Alfred A. Skrocki
alfred.skrocki-at-cybernetworking-dot-com
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