Huge laser experiment to reconstruct conditions at Sun's heart

Scientists are all set to begin the U.S. National Ignition Facility (NIF), which is literally a huge laser experiment aimed at recreating conditions at the heart of our Sun. According to a report, the experiment is designed to demonstrate the feasibility of nuclear fusion, a process that could offer abundant clean energy.

The lab will kick-start the reaction by focusing 192 huge laser beams on a tiny pellet of hydrogen fuel. To work, it must show that more energy can be extracted from the process than is required to initiate it.

The California-based NIF is the largest experimental science facility in the U.S. and contains the world's most powerful laser. It has taken 12 years to build. "This is a major milestone," said Dr Ed Moses, director of the facility.

But the challenge of creating a practical fusion reactor has eluded scientists for decades. Now, however, they believe they are nearing their goal. Fusion naturally occurs at the center of stars where huge gravitational pressure allows the process to happen at temperatures of about 10 million Celsius.

"We are well on our way to achieving what we set out to do - control, sustained nuclear fusion and energy gain for the first time ever in a laboratory setting," he added. Experiments will begin in June 2009, with the first significant results expected between 2010 and 2012. Fusion is looked on as the "holy grail" of energy sources because of its potential to supply almost limitless clean energy.

At the much lower pressures on Earth, temperatures to produce fusion need to be much higher - above 100 million Celsius. If it works, NIF will release 10 to 100 times more energy than the amount pumped into the lasers to kick-start the reaction.