Lightning rods have been used to direct lightning strikes for centuries, but now scientists are demonstrating something a little more advanced than the humble metal rod. It has been shown that lightning is deflected when illuminated with This could lead to laser lightning rods that protect a wider range from dangerous attacks.
Lightning is one of the most energetic natural phenomena, producing millions of volts in an instant. Of course, it can be destructive, damaging buildings, cutting power, causing fires, and causing injuries and deaths.
For centuries, lightning rods have been our best defense against lightning strikes. This is a simple metal rod attached to a skyscraper that attracts electricity and guides it safely to the ground. However, their scope is limited. A 10 m (33 ft) lightning rod can protect an area as small as 10 m around you. Protecting large buildings like airports and wind farms requires impractically large lightning rods.
European researchers are now demonstrating new systems that are more effective. Laser lightning rods (LLRs), as the name suggests, shoot lasers into clouds during a storm, creating the path of least resistance for electricity to flow. It can also stretch much longer than a lightning rod.
“When a very high-power laser pulse is emitted into the atmosphere, a very intense filament of light is formed inside the beam,” said Jean-Pierre Wolf, the last author of the study. increase. “These filaments ionize the nitrogen and oxygen molecules present in the air, releasing free electrons to move. This ionized air, called ‘plasma,’ becomes a conductor. “
To prove this concept, scientists developed a new laser system with an average power of 1 kW. It pulses approximately 1,000 times per second, emitting 1 Joule of energy per pulse. It was installed on top of Sentis, the highest mountain in the Swiss Alps, near the tower where about 100 lightning strikes occur each year.
From June to September 2021, the team tested the system during storms that hit the region. The laser was shot into the sky near the top of the tower in order to try to guide the lightning into a beam before it reached the tower’s usual lightning rod. That summer, he had four lightning strikes on the tower while the laser was on, bending the bolt.
Xavier Rabinette – UNIGE
“From the initial laser lightning event, we found that the discharge followed the beam almost 60 m (197 ft) before reaching the tower, increasing the radius of the protective surface from 120 m to 180 m (394 to 590 ft). ),” said Wolfe.
The idea of using lasers as lightning rods has been around for some time and has shown promise in laboratory experiments, but the team says this is the first time it’s been demonstrated in the real world. Other scientists have suggested that a graphene tractor beam could do a better job, but it would require a more complicated setup.
The ultimate goal of the LLR project is to use lasers to extend the impact of a 10 m lightning rod by 500 m (1,640 ft), the team said.
A study was published in a journal nature photonicsThe team describes their work in the video below.
Deflect lightning with a laser lightning rod / Deflect lightning with a laser lightning rod
Source: UNIGE
