Laser beam guides lightning bolts to a ground target

U.S. Army develops Zeus-like weapon
June 28, 2012

A guided lightning bolt travels horizontally, then hits a car when it finds the lower resistance path to ground. The lightning is guided in a laser-induced plasma channel, then it deviates from the channel when it gets close to the target and has a lower-resistance path to ground. (Credit: U.S. Army)

Scientists and engineers at the U.S Army’s Picatinny Arsenal are developing a device that can shoot lightning bolts down laser beams to destroy its target.

The Laser-Induced Plasma Channel (LIPC) is designed to take out targets that conduct electricity better than the air or ground that surrounds them.

“Light travels more slowly in gases and solids than it does in a vacuum,” explained George Fischer, lead scientist on the project.

“If a laser puts out a pulse with modest energy, but the time is incredibly tiny, the power can be huge,” he said. “During the duration of the laser pulse, it can be putting out 50 billion watts, more power than a large city needs, but the pulse only lasts for two-trillionths of a second.

“For very powerful and high intensity laser pulses, the air can act like a lens, keeping the light in a small-diameter filament,” said Fischer. “We use an ultra-short-pulse laser of modest energy to make a laser beam so intense that it focuses on itself in air and stays focused in a filament. The plasma channel conducts electricity way better than un-ionized air, so if we set up the laser so that the filament comes near a high voltage source, the electrical energy will travel down the filament.”

A target, an enemy vehicle or even some types of unexploded ordnance, would be a better conductor than the ground it sits on. Since the voltage drop across the target would be the same as the voltage drop across the same distance of ground, current flows through the target. In the case of unexploded ordnance, it would detonate, explained Fischer.