Underwater ball lightening

[ebeuerle]

I saw this on NewScientist.com and since we have had previous discussions on ball lightening I thought some people might find it interesting. Only needs 5KV and lots of amps.
http://www.newscientist.com/article/dn9 ... -fire.html
-Eddie B.

[Javier Lopez]

May be very beautiful, but not interesting for fusion. Cross section at <5kV is too little.

[Richard Hull]

Water arc explosions. I've Been there, done that, in a peer reviewed paper in the Journal of Plasma Physics in 2000.

Interesting energy returns, but we figured it all to be chemical bond energy. It is in the paper.

Water is probably a key to something related to energy issues but it eludes me as to the specific path.

Interestingly, we used 5kv to 20kv and used thousands of peak amp pulses. We also used an accelerator gun and not an open jarl of water.

Richard Hull

[David Rosignoli]

Richard,

How much stored energy did you use in your capacitor bank? Judging by their schematic, these folks used 500uF at 5kV -> 6.2kJ. Still, they are quoted as using 60A, not 1000s. I wonder if anyone has mapped out the energies and voltages for water arc explosions/ball lightning. I suppose you, Hathaway, or the Greneaus looked at this at least in regards to energy gain (not BL). I wonder if their is an English version of their paper.
-Dave

[Scott Fusare]

The original work on this technique was done by Emelin and Pirozerski some 5 years ago. More details and many photos are available on thier website at http://balllightning.narod.ru/ as well as in several english translations of thier papers. That said, the properties of this plasmoid bear little resemblance to those reported for ball lightning.

[Richard Hull]

Thanks Scott for giving the refs needed.

The bulk of our work was done at about 50-200 joules. The largest shot I ever did was 300 Joules. This energy was enough to disentergrate the breech block of the gun making it a one shot device before a remachining of a new breech block was necessary (2 hour job). We relied on an ultra sharp water dielectric explosion in ~ 1cc of water.

My current demo gun, often fired at my High Energy conference each year, uses a special formula one racing plug as the breech block and it is a bit tattered, but still intact after about 60 shots @ 60 -100 joules. This is a ceramic plug, effectively, and can be replaced by a simple unthread operation.

Geoge Hathaway reported to me that at 500 joules you might only get 2 shots even with this expensive $10.00 plug. Still, it is readily replacable.

Richard Hull

[DaveC]

I was also surprised that it was only 60 A (presumably the peak current). I think the clay tube has something important to do with restricting the current. Clay can be used as the equivalent of a semi-permeable membrane, and functions as an electrophoresis medium. Under steady DC conditions, water can be pumped out of the clay, leaving a quite dry condition behind.

It's hard to see that happening over any distance in the time frame of a capacitive discharge, but it doesn't take much liquid water to make a vapor filled sphere, and even less if it truly gas or ion filled.

But I don't really have a clear idea of their experimental setup based on the descriptions I've read, so far.

But interesting , none the less.

Dave Cooper

[Wilfried Heil]

Here is a photo of their setup (Press page of the HU University in Berlin):

>http://www.ipp.mpg.de/ippcms/de/presse/pi/05_06_pi.html

Looks like it should be easy to replicate. We'll see.

Like Scott has noted, the original work was done by Emelin and Pirozerski a couple of years ago. The HU just needed something impressive for their open day to the public.

[Scott Fusare]

This is identical to the Russian setup. I found my copy of the English translation of the work as published in "Technical Physics". If anyone is interested I could (briefly) post it in the files section.

Note that what is going on here is very different from Richard's water arc experiments which involved complete electrode to electrode breakdown. In the case at hand the current is limited by the "water resistor" through which it flows, hence the relativly small current.

[DaveC]

Thanks Wilfried and Scott. It does look simple. Wondering if it much more than a ionized gas "smoke ring" generator.

If the 300 msec time is considered a "time constant" of the discharge circuit, then I calculate about 600 K equivalent resistance through the water, if nothing else is in series.

Interestingly, using 2,000 ohm -cm water resistivity, ( typical value for tap water), and an otherwise insulated bare ended 1mm diameter wire, I get about 0.25 Megohm contact resistance to the water plus whatever effective resistance there is to the ring electrode. Order of magnitude close.

Fascinating in any regard.

Dave Cooper

[Javier Lopez]

500Joules shot was adiabatic?