Re: very long sparks

To: tesla-at-pupman-dot-com
Subject: Re: very long sparks
From: Bert Hickman <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Wed, 05 Jan 2000 22:19:51 -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
> 
<SNIP>

Dr. Resonance and all,

I can confirm that it is indeed a free-air negative discharge
originating off the flat top of what appears to be a huge cylindrical
impulse generator, and is shown on page 4 of Bazelyan and Raizer's
"Spark Discharge". The picture and associated text indicates it's from
(only!) a 5 MV pulse, done at the Siberian Institute for Power
Engineering (complete with snow on the ground). It's arcing to a 110 kV
transmission line about 100 meters away. A BIG, lightning-like
discharge. GREAT book.

-- Bert --