WASHINGTON — Next year will mark the 50th birthday of the laser, one of the most productive and widely used mega-inventions of the past 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 sincelasers 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 laser printers, perform surgery, diagnose and treat cancers, spot military targets and measure the distance to the moon. They even remove unwantedbody 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 nuclear fusion, 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 hydrogen atoms to fuse, or combine. The combination loses a tiny bit of mass,which turns into a huge quantity of energy.
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 years away.
A rival fusion system, using powerful magnets instead of lasers, is being developed, but it hasn’t yet proved to be successful.
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-size pellet ofdeuterium 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 Xrays, 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 achieveignition 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.
Business, Pages 12 on 12/21/2009