Sciencemadness Discussion Board

Exploding Wires, by Stephen P. Hansen

watson.fawkes - 2-2-2012 at 20:30

Steve Hansen, who runs the lovely site the Bell Jar about vacuum technology, recently put up a pamphlet he wrote called "Exploding Wires". It was formerly available through Lindsay Publications, now a free PDF download.

It's only 11 pages, but it's a very good start for someone who's never done any HV work before; it's very practical. It pushes off the HV power supply issue to the ARRL Handbook, but is otherwise fairly complete in terms of constructing a first test apparatus and putting metal marks on a medium. The author is fond of the blues and greens from copper wire. There's a nice diagram for a drop relay built of hardware-store parts; this is a way of discharging the capacitor remotely. There's also a rather interesting set-up for doing explosive forming by detonating a wire under water; no chemical boost required.

Consider this a learning primer, rather than any kind of authoritative source.

Xanthippe - 3-2-2012 at 14:37

I used to get Steve's Bell Jar news letter. It was great. I also posted about exploding wires on my MySpace page. It makes lots of noise.

I'm the one who wrote the X-ray project at http://www.belljar.net/xray.htm
Lol, I still glow in the dark!

watson.fawkes - 4-2-2012 at 17:09

Quote: Originally posted by Xanthippe  
I'm the one who wrote the X-ray project at http://www.belljar.net/xray.htm
It's a good article. One thing I didn't really get until recently is that the Crookes tube is actually Victorian-era technology. So for that hipster who really wants that steampunk frisson, an X-ray gun is just the thing. But they'll have to find or fabricate their own tube; no fair repurposing later tube technology as you outline.

AndersHoveland - 14-2-2012 at 02:41

The interesting thing with exploding wires is that the localized explosion can potentially be more powerful than a chemical explosion.

Wire explosions have even been successful at initiating fusion:
http://en.wikipedia.org/wiki/Z_machine

I would like to have one of these Marx generators:
http://www.amazing1.com/marx_generators.htm
(starting at only 8500 USD!)

[Edited on 14-2-2012 by AndersHoveland]

quicksilver - 14-2-2012 at 08:10

I have made several Marx Generators and Cockcroft Walton Generators and the CW design is more robust (IMO). Below is an Excel spreadsheet for working out your needs (on either actually).
This is the standard CW schematic for the single doubler: expanding this to several lengths will get some serious energy.

CW_schematicyellow.GIF - 2kB

Attachment: Multiplier Design.xls (219kB)
This file has been downloaded 635 times

Here are other examples where a doubler is made into a quad. The importance of quality materials cannot be overstressed.

[Edited on 14-2-2012 by quicksilver]

cw11.gif - 4kBcw12.gif - 5kB