LIVERMORE, Calif. - By the end of 2010, scientists at Lawrence Livermore National Laboratory may be celebrating the realization of a decades-long dream: re-creating the reaction that powers the sun and causes hydrogen bombs to explode.

Or they'll be sitting on one of the biggest failures in the history of science.

The project, called the National Ignition Facility, or NIF, takes up most of a building the size of two football fields. Inside, 192 of the world's most powerful lasers are focused to concentrate unprecedented power into a target of hydrogen atoms, coaxing them to fuse into helium.

The project, at $5 billion, is already more than seven years behind its original completion date and four times over budget. It's running, but hasn't yet achieved its goal of liberating more energy from the fuel than scientists pump in. They are now promising to do it by the end of this year, though a report last week by the Government Accountability Office called that unlikely.

If that doesn't happen, a failure of such size and scope would threaten Livermore's credibility and call into question the mission of the other weapons labs in the post-Cold War era.

In the 1990s, NIF was billed as a way to ensure the reliability of our nuclear weapons without having to test them. The United States stopped testing nuclear weapons in 1992 and signed an international test-ban treaty in 1996. NIF was originally proposed to help the United States lead the world in ending nuclear testing and thus prevent nuclear proliferation.

But more recently, Livermore scientists have been touting it as a stepping-stone to commercial fusion power - potentially a clean and unlimited source of energy - an assertion that critics call a long shot.

Decorating one side of the NIF building is a billboard-size poster with a striking image of a sunrise shining over the surface of a blue planet. The slogan reads, "Bringing Star Power to Earth."

If NIF works as promised, it would create the world's first controlled version of the nuclear fusion that powers the stars. Instead of splitting the nuclei of the largest atoms, the machine will coax the smallest ones to merge. Both fission and fusion convert traces of mass into copious quantities of energy.

In NIF, the actual fusion takes place in a target smaller than a pea.

All the heavy equipment surrounding this pea is aimed at getting the temperature up to 180 million degrees Fahrenheit and compressing the hydrogen fuel to 100 times the density of lead. For that, they use the world's most energetic lasers, 192 of them, all converging on this speck.

When proposed in the mid-1990s, NIF was supposed to cost $1.2 billion and be finished by 2003. Congress almost balked at that original price, which has since risen to $5 billion.

Ignition

Livermore physicist Chris Keane said that the scientists were close. Earlier this year, they turned on all 192 lasers simultaneously and aimed them at various targets. Everything appears to line up perfectly.

Now all they need to do is achieve what's called ignition - sparking a brief, self-sustaining fusion reaction that liberates more energy from the fuel than the lasers use up.

The NIF building has a small exhibit in its lobby, with images of colorful stars and nebulae and a glass case housing a sample of the pink glass that amplifies the laser beams - a product of several companies, including Schott Glass in Duryea, Pa., between Wilkes-Barre and Scranton.

Laser light striking the glass results in even more laser photons' being emitted. The first laser was developed in 1960 and is based on the phenomenon of stimulated emission, first discovered by Albert Einstein, said Keane.

Also on display is a single, clear crystal the size of a suitcase. At the last minute, the scientists realized they needed these to adjust the wavelength of their lasers, Keane said, and so they had to figure out a way to mass-produce the giant crystals.

"This is the largest precision optical instrument ever created," he said. There were all kinds of technological barriers they had to cross to get there.

While not running, NIF looks like a factory. From a catwalk high above the main floor, hard-hatted workers scurry around with carts of cables and machinery.

Bursts of fusion

At the heart of the experiment is a 30-foot-diameter ball full of round windows - like portholes in a submarine.

That's the target chamber, Keane said.

When they run the machine, they will suspend a BB-size capsule in the exact center. For days afterward, the target-chamber area will remain off-limits to allow decay of all radioactive material resulting from neutrons and X rays created in the fusion reaction.

They can use different materials for their targets, but for full ignition, they plan to aim all their lasers at a combination of heavy isotopes of hydrogen, called deuterium and tritium.

They're already getting small bursts of fusion, but it doesn't count as ignition unless they generate more energy from the fuel than they expend. The event will last only a fraction of a second, but the physicists say they will be able to prove they got it by the heat and radiation left in the chamber.

Construction of NIF was officially deemed complete a year ago. In spring 2009, Livermore held a news conference with 3,500 people, including California Gov. Arnold Schwarzenegger. At the time, officials boasted about its potential for commercial power - raising hopes that this machine would finally realize the dream of harnessing the sun's power in an apparatus designed to do something other than kill people.

It seemed impractical, but Keane said you would be surprised how much power you could, in theory, "bleed off" from a sand-grain-size piece of the sun.

Commercial power will never come from NIF itself, but if it reaches ignition, Keane said, a power plant might be designed on a similar principle, using "blankets" that would absorb the heat and covert it to electricity.

Physicists outside of Livermore consider the power-plant idea to be far-fetched - "it would take several miracles," Princeton physicist Frank von Hippel said.

About 80 percent of the experiments done on NIF will be focused on the core mission - to understand the reactions that go on in nuclear weapons.

'Nothing'

And even there, many scientists doubt that NIF's results will ever translate into anything related to national security. "In my opinion, NIF has nothing significant to do with the safety or reliability of the stockpile," said Arjun Makhijani, a nuclear engineer who heads the nonprofit Institute for Energy and Environmental Research. "For $5 billion, even if it works perfectly, you're getting nothing."

NIF, he said, fails to address the safety of nuclear weapons - keeping them from detonating after being stolen, or following a crash, for example. And a number of experts say safety is much more important than reliability.

"The Department of Energy talks about safety and reliability as if they're the same thing," he said. "That's the warm-fuzzy-teddy-bear approach to nuclear weapons."

In reality, they are polar opposites, he said. "Safety is when you don't want them to go bang; reliability is when you want them to go bang."

And we know errors happen, he said. "Remember when we had those six weapons that flew off from North Dakota on their own?" he said, referring to an infamous 2007 incident.

Princeton's von Hippel says NIF is part of what was essentially a huge bribe to get the national labs to agree to the comprehensive test-ban treaty back in the 1990s. They agreed to go along with an indefinite moratorium on testing, he said, as long as the government gave them as much money to not test their weapons as it gave them to test them.

"I think," von Hippel said, "NIF was an extravagance."

Contact staff writer Faye Flam
at 215-854-4977 or fflam@phillynews.com.