Making lightning with a thin wire

I think lightening is way up in the Megavolts....

Some researchers down south, use model rockets with fine wire attached and attached to the earth to trigger lighting strikes when the conditions are right. I guess if you have enough energy you can vaporize the wire.

Cheers

Be careful: 50us isn't fast enough.

But it could work if the vaporized wire created ionized path.

I am trying to find a thin enough wire, and then I will give it a try.

While in college, I worked in an on campus instrumentation lab. Our job was to build whatever it was that researchers needed. I was given the task of designing an safe fuse and detonator for an acetelyne/oxygen bomb developed by the US Bureau of Mines. It was called a CERB (Controlled Electronic Rock Blaster).

The fuse consisted of a piece of #30 wirewrap wire strung between two mounts. This was sealed into the gas mixture housing. The fuse was considered safe since only a huge amount of energy could cause ignition.

Ignition was accomplished by charging a large capacitor (5 uF) to 15 KV. This cap was the input to a triggered spark gap. The output was the #30 wire in the gas mixture chamber. The cap was charged, arming the circuit, and then the spark gap trigger by a thyraton, causing the cap to be discharged into essentially a short.

The discharge event lasted less than 5 usec, in which time, the wire would vaporize igniting the gas mixture. A combustion wave would propagate down the cylinder, and at 100K psi, a shear plate would release, sending a shock wave down toward the area to be "blasted". The theory was that the shock wave could be more controlled, better directed, and the blast would consume less energy than conventional explosives.

This was one of the best projects I ever got to work on. The first test was in a basement lab and we had no idea what the effect of that kind of force would be. The room was destroyed. The shear plate punched a hole in the concrete wall, all the lights were in shambles. Later, a steel plate was used as the target and even this ultimately had a hole abraded through it.

The first field test was also spectacular. The CERB was untethered, and when detonated, shot straight up in the air like the rocket it was with only the fuse and detonator wires to limit its flight.

Other labs were working on the approach as well. The highest energy data point could never be replicated because the researcher lost his lab in the experiment. Our work was directed by Thomas Blythe, whose brilliant career was shortened by some tough disease.

Blakely

Don't you just hate it when that happens!

What explosives did you use? Perchlorate and...???

Michael

Pretty much what I did this evening. Same voltage even. It was LOUD. OMG. What did you say?

That was used in some nuclear weapons also (blast directing foil onto the secondary explosive).

sounds like fun.

The actual explosive was just an acetylene and oxygen mixture, chosen for its cheapness and ease of handling. The gases were injected into a combustion chamber (6 inch x 3 foot cylinder). Shear plate on one end, fuse on the other, gases in between.

One of the other pieces of equipment that we designed was an Ion conductivity gauge which allowed the researchers to measure the speed of the combustion wave as it propagated down the cylinder by measuring the change in conductivity of electrodes inserted into the cylinder down its length.

Blakely

That can be quit a spectacular mixture, the mechanic at the local garage in Bradford apparently complained about an acetylene leak one night, IIRC, but was told just to ignore it, the next day there was nothing to be seen for a considerable distance around where the garage used to be.

Colin =^.^=