Military

U.S. Army weapon shoots lightning bolts down laser beams

U.S. Army weapon shoots lightn...
A lightning bolt travels horizontally down a plasma channel from the LIPC before deviating when it gets close to the target which offers a lower-resistance path to the ground (Photo: U.S. Army)
A lightning bolt travels horizontally down a plasma channel from the LIPC before deviating when it gets close to the target which offers a lower-resistance path to the ground (Photo: U.S. Army)
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A lightning bolt travels horizontally down a plasma channel from the LIPC before deviating when it gets close to the target which offers a lower-resistance path to the ground (Photo: U.S. Army)
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A lightning bolt travels horizontally down a plasma channel from the LIPC before deviating when it gets close to the target which offers a lower-resistance path to the ground (Photo: U.S. Army)

Thought that title might get your attention, but shooting lightning bolts down laser beams is just what a device being developed at the Picatinny Arsenal military research facility in New Jersey is designed to do. Known as a Laser-Induced Plasma Channel, or LIPC, the device would fry targets that conduct electricity better that the air or ground that surrounds them by steering lightning bolts down a plasma pathway created by laser beams.

The pathway takes the form of an electrically conductive plasma channel that is formed when a laser beam of enough intensity (a 50 billion watt pulse lasting two-trillionths of a second will do) forms an electro-magnetic field strong enough to ionize the surrounding air to form plasma. Because the plasma channel conducts electricity much better than the non-ionized air that surrounds it, electrical energy will travel down the channel.

Then, when it hits its target – an enemy vehicle, person or unexploded ordnance, for example – the current will flow through the target as it follows the path of least resistance to the ground, potentially disabling the vehicle or person and detonating the ordnance. The lightning will also deviate from the channel when it gets close to the target and finds a lower-resistance path to the ground.

That’s the basic physics behind it, but overcoming the technical challenges to actually build the device won’t be easy.

"If the light focuses in air, there is certainly the danger that it will focus in a glass lens, or in other parts of the laser amplifier system, destroying it," said George Fischer, lead scientist on the project. "We needed to lower the intensity in the optical amplifier and keep it low until we wanted the light to self-focus in air.”

The research team also had to synchronize the laser with the high voltage and ruggedize the device so it could be operated under extreme environmental conditions. There is, of course, also the problem of providing enough power to operate the device for extended periods of time. Despite these challenges, the team claims to have made notable progress in recent months after reporting "excellent results" in tests conducted in January, 2012.

Work on the device is continuing.

Source: U.S. Army via engadget

28 comments
Tom Phoghat Sobieski
"potentially disabling the vehicle or person" How euphemistic ! Like "terminating with extreme prejudice" BTW, didn't I see this in a movie with Ahhnold?
Slowburn
I considered the idea years ago but decided that once you have a laser capable of generating the plasma trail the electrical discharge would be superfluous. The laser could also be useful as an active lightning rod system whether or not you can use the super surge of electricity.
Jacob Shepley
don't use this in a thunderstorm.... :P
Daniel Tan
Don't get it. If you have enough energy to fire a laser beam... why don't you just use the laser beam to destroy whatever target you want to destroy... since it's a 50 billion watt laser, I'm pretty sure it's stronger than a jolt of electricity, even if it only lasts 2 trillionths of a second. In fact, this is probably better, because this can be targeted accurately (say at the engine of an enemy tank 100 km away) and nobody will be able to see it. The target would just explode seemingly spontaneously. common sense, anybody?
Mark Gilbreath
@Daniel Socrates Tan One thing you need to know about tactical lasers, is that they aren't instantaneous. It takes a good twenty seconds of exposure to burn a hole in a missile or vehicle. And that still doesn't guarantee that it will explode. Plus, the point of this weapon is to be tunable to different targets and sometimes 'NOT' to fry them on purpose.
VirtualGathis
For those asking the question why not just use the laser to do the damage... Most of you are leaving off the most important measure of the laser pulse: "two-trillionths of a second" That is Two picoseconds. If you hit a soft target like a person with that you might reasonable be ale to do some harm but it would only be skin deep (better hope you hit him in the eyes). A hard target like a vehicle wouldn't even notice it. You would need to be able to maintain the beam for almost a full second to do significant damage to a vehicle especially an armored vehicle. Electricity on the other hand can destroy electronics, and nerve pathways with a very brief pulse. So in short the laser pulse duration is too brief to do damage, current laser technology would vaporize itself before delivering that kind of power for a usefull timespan, and electricity can do much more damage.
Jay Lloyd
Slowburn, are you a defense contractor? Since you are always on top of all the new defense technologies, maybe you should be getting paid for it. Also, the laser must not last long enough to do any real damage, or else they would not have even considered using it in this manner. 50 billion watts is a hell of a lot to keep going. The electricity jolt could be controlled enough that it can knock a person out, disable a vehicle, or detonate an explosive device. You don't even have to aim it perfectly to hit a huge tank with it, just be near enough that it takes the path of least resistance.
Mirmillion
Why not deliver a charge sufficiently disruptive to the very structure (or parts of) the object to be "affected"?
erock5000
@Daniel Socrates Tan C'mon, everyone knows that laser beams are blue, unless you're the bad guy, then they're red...
jerryd
The problem is how are you going to put the steel ground plates under the target? Next a laser heats the air, not generatoe an electromagnetic field. Electricity does take the path least resistance but that isn't nessasarily the target. It might just as well be the shooting vehicle, humid air, etc.