Re: very long sparks

To: tesla-at-pupman-dot-com
Subject: Re: very long sparks
From: David <davmckin-at-ix-dot-netcom-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Thu, 06 Jan 2000 19:49:29 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Tesla List wrote:
> 
> Original Poster: "Dr. Resonance" <Dr.Resonance-at-next-wave-dot-net>
> 
> to: Jim
> 
> If this was an impulse test, question:  Was the spark in free air or across
> a string of insulators?  If across a string of insulators I have stretched
> 1,000,000 volts to over 23 feet, but that doesn't count as a free air spark.
> 1 MEV in free air at 250 KHZ with a break rate of 450 PPS at a power level
> of 7.5 KVA will stretch to approx 9 feet.
> 
> Perhaps someone on the list that has a copy of the book could comment on
> whether it was a 100 meter free air discharge or 100 meters creepage
> flashover along an insulator string.
> 
> Regards,
> 
> Dr. Resonance

> >Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> >Les Renardiers group in France built a generator in
> >the 8-9 MV range which produced long sparks (I'd
> >expect >50 meters, but I don't have the reference
> >handy), and in Bazelyan and Raizer ("Spark Discharge")
> >there is an impressive photo of a 100+ meter (thats
> >meters, folks, not feet) spark in an outdoor test lab.

Dr. Resonance, Jim, list,

It was a free air spark.  I did hear of a story that when
they set off the Impulse Generator one time it arced
over a row of trees to a lamp post in the employee parking
lot - unfortunately, I have nothing solid to back that
story I heard up.  But the length mentioned was 300 feet,
and from someone who was at that facility at the time it
happened.

David L. McKinnon
D&M's High Voltage