Fusion "Breakthrough" At National Ignition Facility? Not So Fast

sciencehabit writes "One unintended effect of the U.S. federal shutdown is that helpful press officers at government labs are not available to provide a reality check to some of the wilder stories that can catch fire on the Internet. They would have come in handy this week, when a number of outlets jumped on a report on the BBC News website. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California, it reported, had passed a 'nuclear fusion milestone.' NIF uses the world's highest energy laser system to crush tiny pellets containing a form of hydrogen fuel to enormous temperature and pressure. The aim is to get the hydrogen nuclei to fuse together into helium atoms, releasing energy. The BBC story reported that during one experiment last month, 'the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel — the first time this had been achieved at any fusion facility in the world.' This prompted a rush of even more effusive headlines proclaiming the 'fusion breakthrough.' As no doubt NIF's press officers would have told reporters, the experiment in question certainly shows important progress, but it is not the breakthrough everyone is hoping for."

Comments

Blowing out of proportion

[Geoffrey.landis]

There's a good discussion by Jeff Hecht in the Laser Focus World blog: "Progress at NIF, but no 'breakthrough'"
http://www.laserfocusworld.com/articles/2013/10/progress-at-nif-but-no-breakthrough.html

The amount of energy generated by fusion is quoted as having exceeded the amount of energy absorbed by the fusion fuel [my italics].

The misleading part comes from the fact that the target absorbs only a small fraction of the energy in the laser pulse. The August experiments used a laser pulse of 1.7 million joules to generate 8000 joules of fusion energy (measured from neutron yield). So the fusion energy amounts to a few percent of the energy in the laser pulse (and much less if you account for the inefficiency of the laser).

Re:Blowing out of proportion

[Anonymous Coward]

It's not tough "science". The science is known since decades. It's tough ENGINEERING, which is another story altogether.

Re:Blowing out of proportion

[catmistake]

So the fusion energy amounts to a few percent of the energy in the laser pulse (and much less if you account for the inefficiency of the laser).

The estimates become even more dubious when you account for all the energy expended training, feeding and housing the sharks.

Re:My worry

[ColdWetDog]

My worry is that these people don't really know what they're doing, and that they're going to ignite a fusion reaction that will be self-feeding and turn our planet into a sun.
This is one area of research where a mistake can really ruin the environment.

Don't worry. All you need to do is unwrap the entire roll of aluminum foil and cover your whole body. You'll be safe then.

From quite a lot of things, actually.

BBC reported correctly

[Anonymous Coward]

actually the BBC's story reports correctly -
"The BBC understands that during an experiment in late September, the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel - the first time this had been achieved at any fusion facility in the world.

This is a step short of the lab's stated goal of "ignition", where nuclear fusion generates as much energy as the lasers supply. This is because known "inefficiencies" in different parts of the system mean not all the energy supplied through the laser is delivered to the fuel."

Re:Wait, The Internet?

[lxs]

Space elevator went live last week. Sadly some joker pressed all the buttons. At this rate they'll reach the moon by 2035.