Category: laser

Researchers have created a new giant dual-laser that could control the weather

On By A.P.In Da Brayn, laser, Nature Photonics, Science, Technology, University of Arizona, University of Central Florida, Weather, weather controlLeave a comment

Zeus, God of the Sky, may be out of work, as scientists at the University of Central Florida believe they’ve developed a technique — which involves pointing a high powered laser at the sky — to induce clouds to drop rain and hurl thunderbolts.

Scientists have known that water condensation and lightning activity in storm clouds are associated with large amounts of static charged particles. In theory, stimulating those particles with a laser is the key to harnessing Zeus-like powers.

The hard part, scientists say, is creating a laser beam with the right combination of range, precision and strength.

“When a laser beam becomes intense enough, it behaves differently than usual — it collapses inward on itself,” explained Matthew Mills, a graduate student in the UCF Center for Research and Education in Optics and Lasers. “The collapse becomes so intense that electrons in the air’s oxygen and nitrogen are ripped off creating plasma — basically a soup of electrons.”

But students at UCF’s College of Optics & Photonics have collaborated with researchers at the University of Arizona to create a “dressed laser” that they think might be up for the challenge of controlling the weather.

The dressed laser is a high-power laser beam surrounded by a second beam, which acts as a refueling agent, sustaining the strength and accuracy of the central beam over longer distances.

“Since we have control over the length of a filament with our method, one could seed the conditions needed for a rainstorm from afar,” said Mills. “Ultimately, you could artificially control the rain and lightning over a large expanse with such ideas.”

The students recently published their research findings in the journal Nature Photonics. Their efforts were supported by a $7.5 million grant from the Department of Defense.

Read more: http://www.upi.com/Science_News/2014/04/19/Giant-lasers-could-control-the-weather/1691397928851/#ixzz2zRZl9YTP

Thanks to Da Brayn for bringing this to the attention of the It’s Interesting community.

Berkeley Laser Fires Pulses Hundreds of Times More Powerful Than All the World’s Electric Plants Combined

On By A.P.In BELLA, Berkeley, Berkeley Lab Laser Accelerator, Department of Energy, femtosecond, Inventions, laser, laser wakefield acceleration, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, petawatt, Science, Stanford Linear Accelerator Center, Wim LeemansLeave a comment

Blink and you’ll miss it. Don’t blink, and you’ll still miss it.

Imagine a device capable of delivering more power than all of the world’s electric plants. But this is not a prop for the next James Bond movie. A new laser at Lawrence Berkeley National Laboratory was put through its paces July 20, delivering pulses with a petawatt of power once per second. A petawatt is 1015 watts, or 1,000,000,000,000,000 watts—about 400 times as much as the combined instantaneous output of all the world’s electric plants.

How is that even possible? Well, the pulses at the Berkeley Lab Laser Accelerator (BELLA) are both exceedingly powerful and exceedingly short. Each petawatt burst lasts just 40 femtoseconds, or 0.00000000000004 second. Since it fires just one brief pulse per second, the laser’s average power is only about 40 watts—the same as an incandescent bulb in a reading lamp.

BELLA’s laser is not the first to pack so much power—a laser at Lawrence Livermore National Laboratory, just an hour’s drive inland from Berkeley, reached 1.25 petawatts in the 1990s. And the University of Texas at Austin has its own high-power laser, which hit the 1.1-petawatt mark in 2008. But the Berkeley laser is the first to deliver petawatt pulses with such frequency, the lab says. At full power, for comparison, the Texas Petawatt Laser can fire one shot per hour.

The Department of Energy plans to use the powerful laser to drive a very compact particle accelerator via a process called laser wakefield acceleration, boosting electrons to high energies for use in colliders or for imaging or medical applications. Electron beams are already in use to produce bright pulses of x-rays for high-speed imaging. An intense laser pulse can ionize the atoms in a gas, separating electrons from protons to produce a plasma. And laser-carved waves in the plasma [blue in image above] sweep up electrons [green], accelerating them outward at nearly the speed of light.

BELLA director Wim Leemans says that the project’s first experiments will seek to accelerate beams of electrons to energies of 10 billion electron-volts (or 10 GeV) by firing the laser through a plasma-based apparatus about one meter long. The laser apparatus itself is quite a bit larger, filling a good-size room. For comparison, the recently repurposed Stanford Linear Accelerator Center produced electron beams of 50 GeV from an accelerator 3.2 kilometers in length.

http://blogs.scientificamerican.com/observations/2012/08/01/berkeley-laser-fires-pulses-hundreds-of-times-more-powerful-than-all-the-worlds-electric-plants-combined/

Thanks to Ray Gaudette for bringing this to the attention of the It’s Interesting community.