National Ignition Facility seeks new cash

National Ignition Facility seeks new cash
David Perlman
San Francisco Chronicle
Tuesday, December 4, 2012

The elusive effort to mimic the explosive violence of hydrogen bombs inside Livermore's giant National Ignition Facility, long delayed, now faces intense scrutiny by a dollar-conscious Congress.

The National Nuclear Security Agency in charge of the Lawrence Livermore National Laboratory says in a draft report to Congress that the lab's scientists should conduct at least three more years of experiments. An estimated $5 billion or more has been spent over the past 10 years to build and run the project called NIF, and current experiments are running at least $450 million a year.

Congress had set the end of this year as the deadline for "ignition," as the goal is termed. Now the nuclear agency's report says the extension is needed for NIF scientists to consider two very different and untried technical approaches to the extraordinarily complex physics problems that have prevented them so far from achieving their goal of duplicating the explosion of an H-bomb in the lab.

Congressional experts are reviewing the report and some are highly skeptical about its eventual success. The final report from the nuclear security agency is expected early next week, when congressional staff specialists will begin considering its implications for NIF's future.

NIF's goal is still "very, very far away," said one congressional expert who follows the technical details closely. The expert, who asked to remain anonymous because he was not authorized to speak publicly about the project, complained that the nuclear agency appears to be asking Congress for a "blank check" until at least 2015.

"They're asking us to give them a blank check ... and then we'd see where we are," the expert said. "That worries me. They're not even close."

The ultimate aim of NIF's nuclear weapons scientists is to understand the obscure physics involved in thermonuclear fusion, validate related computer codes, and thereby assure the safety and reliability of America's aging weapons stockpile without the underground bomb tests that are now banned by international treaty...

But after 35 experiments and more than 1,000 laser shots since NIF scientists began three years ago, the effort has fallen short. In order to achieve ignition, the laser beams would have to produce between three and 10 times more energy and heat than they have been able to accomplish, the report said.

Just where the problems lie remains a mystery. A national committee of laser experts headed by Stanford physicist Robert L. Byer recently had high praise for the NIF laser's "robust operation" and said it has "met and exceeded its design goals." The NIF scientists, the committee concluded, are on a credible path toward upgrading the laser array to reach the energies needed for ignition...

NIF project director Ed Moses declined to comment on the report until its final version is complete. But he said it's impossible to make predictions about success in any field where such complex science is involved...

In experiments so far, the laser shots fired at target after target have yielded pressures 15o billion times Earth's atmosphere, he said, but pressures twice as high are still needed for ignition...

But NIF's giant laser array is now performing spectacularly, he said, and its total output of energy and power is "more than we need," Moses said.