Miracle light: Can lasers solve the energy crisis?

Dec 15, 2009 By Robert S. Boyd

Next year will mark the 50th birthday of the laser, one of the most productive and widely used mega-inventions of the last century. Scientists hope that 2010 also will see the launch of laser technology's greatest challenge: creating an inexhaustible supply of clean, carbon-free energy.

In the five decades since lasers were developed, they've found a host of applications -- from the everyday to the exotic -- in industry, science, medicine, entertainment and national security.

Lasers read bar codes at checkout counters, write and read DVDs, operate printers, perform surgery, diagnose and treat cancers, spot military targets and measure the distance to the moon. They even remove unwanted body hair.

Next year, scientists will take lasers to a new level, trying to produce energy by imitating the way the sun creates the light and heat that support life on Earth.

"Creating star power in the laboratory," is how Edward Moses, the director of the Department of Energy's National Ignition Facility in Livermore, Calif., describes the system.

As the facility's name suggests, the project's scientists are attempting to marry lasers to , the process that fuels the sun, stars and hydrogen bombs.

They hope to use a combination of 192 powerful lasers to generate the extreme heat and pressure that are needed to force to fuse, or combine. The combination loses a tiny bit of mass, which turns into a huge quantity of energy. It's Einstein's formula in action.

In contrast, nuclear power plants today work by fission, splitting apart heavy atoms such as uranium and plutonium to generate energy.

If it works, fusion eventually could power a new class of atomic energy plants. The trick is to build a system that produces more energy than it consumes, a goal that researchers admit is still many years away.

A rival fusion system, using powerful magnets instead of lasers, is being developed, but it hasn't yet proved to be successful. France also has a large laser-fusion research program.

According to the National Ignition Facility, a laser-fusion energy plant would emit no greenhouse gases, would produce few radioactive byproducts and would present no danger of a meltdown. Unlike wind or solar power, it would operate continuously to meet demand. Unlike oil, gas or uranium, its fuel source, mainly hydrogen, is virtually limitless.

To achieve nuclear fusion, the facility's operators hope to focus an array of intense laser beams on a pea-sized pellet of deuterium and tritium -- heavy forms of hydrogen -- in their $3.5 billion plant at Lawrence Livermore National Laboratory near San Francisco.

The beams, which would be transformed into powerful X-rays, would heat and compress the target so that, researchers hope, the fuel would ignite. Ignition would take place in 2 billionths of a second at temperatures of 100 million degrees Celsius and pressures 100 billion times greater than the Earth's atmosphere.

If successful, it would be "analogous to achievement of the first spark ever in an internal combustion engine," Edmund Synakowski, an Energy Department fusion expert, told a congressional panel on Oct. 29. "The pursuit is one of the most challenging programs of scientific research and development that has ever been undertaken."

Moses said the National Ignition Facility hoped to achieve ignition next year, but outside experts think it will take another two or three years to reach that goal, if ever. Many technical problems remain, such as simultaneously and precisely focusing all 192 laser beams on a miniature target without wrecking the whole machine.

"The laser has to go miraculously well" for ignition to occur, said David Hammer, a nuclear engineer at Cornell University in Ithaca, N.Y.

Stephen Bodner, a former director of laser fusion at the Naval Research Laboratory in Washington, accused National Ignition Facility managers in an e-mail of being "unscientifically optimistic. ...There is no way to use the NIF for ignition attempts."

Even the facility's managers say laser fusion won't begin providing electricity to consumers for another 20 years.

"Major technological and engineering challenges will still remain even after the demonstration of ignition," said Riccardo Betti, a physicist at the University of Rochester.

A laser is a device that creates an intense beam of light and focuses it tightly in one direction. The difference between regular light and laser light is like the difference between a water sprinkler and a fire hose.

The story of the laser is a remarkable tale of scientific and technological ingenuity, marred by the usual quarrels and patent fights.

Although the laser concept had been worked out in theory for a century, the first working device was demonstrated on May 16, 1960, by Theodore Maiman, a graduate student at Hughes Research Laboratory in Malibu, Calif.

"The laser era burst open," Anthony Siegman, a retired physics professor at Stanford University in Stanford, Calif., wrote in a book-length history of the invention.

The breakthrough was reproduced immediately by numerous laboratories, and practical applications blossomed.

The first medical use was laser surgery to destroy a retinal tumor at Columbia-Presbyterian Hospital in New York in December 1961. Nowadays lasik surgery -- changing the shape of the cornea to improve eyesight -- is a common procedure. Laser tools remove skin blemishes and tattoos. Dentists drill teeth with them. Factories use them to cut steel or glass. College professors use laser pointers to illustrate their lectures

The first laser was ruby-red, but they now come in multiple colors and strengths. Prices range from a few dollars to millions. A laser can be as small as a microscopic computer chip or as big as the National Ignition Facility, three football fields long.

Scientists use lasers to manipulate electrons, photons and other atomic particles in order to understand fundamental physics.

Just last month, NASA researchers reported using lasers to make extremely tough yarn that could be used for body armor or to shield space ships from radiation.

HOW LASERS WORK

A laser is a device that creates an intense beam of light and focuses it tightly in one direction. The difference between regular light and laser light is like the difference between a water sprinkler and a fire hose.

The name stands for "light amplification by stimulated emission of radiation."

Laser light differs from ordinary light because its photons -- tiny packets of light energy -- are all of the same wavelength and color, and they march in lockstep in the same direction. In contrast, photons in ordinary light scatter every which way.

Laser light is created by a bright flash of ordinary light aimed at a tube of special glass, crystal or gas. The flash pumps extra energy into the tube. That energy "excites" the electrons that are orbiting the nuclei of the atoms in the tube. An excited electron moves up to a higher orbit, then relaxes and drops back to a lower, less energetic orbit. In the process, it emits a photon.

A system of mirrors rapidly bounces the photons back and forth in the laser tube. Photons from one atom stimulate photons from other atoms, amplifying the intensity of the light. The result is a straight, bright beam of laser light.

Lasers can be "tuned" to produce beams of different colors and intensities. Early lasers produced about 10,000 watts. The lasers at the Department of Energy's National Ignition Facility generate trillions of watts.

ON THE WEB

National Ignition Facility: lasers.llnl.gov/
National Ignition Facility Multimedia: lasers.llnl.gov/multimedia/

Explore further: Scientists come up with method of reducing solar panel glare

4.4 /5 (14 votes)
add to favorites email to friend print save as pdf

Related Stories

Giant laser system is under construction

Apr 24, 2008

The world's largest laser system -- the National Ignition Facility -- is being built in California and officials say it will go online next year.

World's largest laser opens (w/Video)

May 29, 2009

Scientists for decades have been hunting for ways to harness the enormous force of the sun and stars to supply energy here on Earth. The National Ignition Facility at the Lawrence Livermore Laboratory may spark the light ...

Laser Fusion and Exawatt Lasers

Oct 01, 2009

(PhysOrg.com) -- In the recent past, producing lasers with terawatt (a trillion watts) beams was impressive. Now petawatt (a thousand trillion watts, or 10^15 watts) lasers are the forefront of laser research. Some labs are ...

Recommended for you

Environmentally compatible organic solar cells

5 hours ago

Environmentally compatible production methods for organic solar cells from novel materials are in the focus of "MatHero". The new project coordinated by Karlsruhe Institute of Technology (KIT) aims at making ...

Floating nuclear plants could ride out tsunamis

6 hours ago

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

Unlocking secrets of new solar material

6 hours ago

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...

Ikea buys wind farm in Illinois

Apr 15, 2014

These days, Ikea is assembling more than just furniture. About 150 miles south of Chicago in Vermilion County, Ill., the home goods giant is building a wind farm large enough to ensure that its stores will never have to buy ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

Nederluv
1 / 5 (3) Dec 16, 2009
Why destroy matter to create energy? Creating matter from energy is harder than the other way around. We need both energy AND matter. The world is soaked in 'free' energy which we receive from the sun. We should use that energy for the coming 4 billion years or so.
Velanarris
not rated yet Dec 16, 2009
Why destroy matter to create energy? Creating matter from energy is harder than the other way around. We need both energy AND matter. The world is soaked in 'free' energy which we receive from the sun. We should use that energy for the coming 4 billion years or so.


There's enough energy within your body's matter to power the entire US for a day or two assuming 100% efficiency. I think we have plenty of matter we can use.
PPihkala
not rated yet Dec 16, 2009
Needed matter in form of water ice rains into earth continuously from space in the form of small icy dust. So we are not going to be running out of matter. Besides, 70% of surface of earth is already covered by that water. Of course currently that problem is only theoretical, as (hot) fusion does not work currently. Still I think that cold fusion should be much more easy to master than this hot fusion.
daveib6
not rated yet Dec 19, 2009
Still I think that cold fusion should be much more easy to master than this hot fusion.

Oh, if it were only that easy. I also would love to believe that the cold fusion reports were acurate, but unfortunately, until the process is refined to be consistently reproducible, it remains only an unproven pipe dream. That said, I agree if your point is that research dollars would be better spent towards refining that process as opposed to this political black hole of research dollars. I predict this will never, ever lead to economical energy production. Anyone second that prediction?

More news stories

Quantenna promises 10-gigabit Wi-Fi by next year

(Phys.org) —Quantenna Communications has announced that it has plans for releasing a chipset that will be capable of delivering 10Gbps WiFi to/from routers, bridges and computers by sometime next year. ...

Floating nuclear plants could ride out tsunamis

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

Unlocking secrets of new solar material

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...

How kids' brain structures grow as memory develops

Our ability to store memories improves during childhood, associated with structural changes in the hippocampus and its connections with prefrontal and parietal cortices. New research from UC Davis is exploring ...

Gate for bacterial toxins found

Prof. Dr. Dr. Klaus Aktories and Dr. Panagiotis Papatheodorou from the Institute of Experimental and Clinical Pharmacology and Toxicology of the University of Freiburg have discovered the receptor responsible ...