Laser fusion put on slow burn
The US National Ignition Facility rethinks its strategy on achieving thermonuclear fusion in the lab, but fails to silence critics.
Geoff Brumfiel
Nature
11 December 2012
The government's new plan, revealed to Nature, calls for a slower, more deliberate approach to achieving ignition: the point at which more energy is produced by a fusion reaction than is consumed. Many physicists believe that this would be an important proof of concept for controlled fusion.
The plan sets a new course for the laser at the National Ignition Facility at the Lawrence Livermore National Laboratory in California. It also promotes the exploration of several alternative ways to reach ignition, including one not involving the laser. And it is more tentative than the previous strategy: it sets a three-year deadline for finding out whether ignition is possible at all, whereas the last one aimed to demonstrate actual fusion...
The US$3.5-billion NIF uses lasers to crush a 2-millimetre pellet of hydrogen fuel to the point of fusion. Rather than irradiating the fuel directly, the lasers shine into a cylindrical capsule. The capsule walls then emit X-rays that squeeze the fuel pellet until it explodes.
This indirect approach mimics the ignition system in a thermonuclear weapon, which uses radiation from a fission 'primary' stage to squeeze hydrogen isotopes in the fusion 'secondary' — creating a powerful explosion.
The NIF's main mission is to gather laboratory data on the process to help weapons scientists to care for the ageing US nuclear stockpile. The United States has adhered to a voluntary moratorium on testing nuclear weapons since 1992, so nuclear scientists must use computer simulations to check that the weapons still work, and NIF data feed into these models.
Physicists at the NIF also hope that the process might pave the way for producing electrical power through thermonuclear fusion.
The latest plan was drafted by the NNSA, which oversees the lab, in response to a congressional request for a strategy for achieving ignition.
Over the next three years, researchers will conduct reduced-power tests to refine their computer simulations and understand why ignition has been so elusive. They will also look at possible improvements to the capsule design.
Other promising approaches to be studied include using lasers to ignite the hydrogen fuel inside the pellet directly, and using a machine called the Z-pinch to squeeze the fuel inside a magnetic field.
By October 2015, the NNSA hopes, it will be able to say whether ignition can be achieved using the NIF or the Z-pinch. Failure, it warns, could have serious implications for the nuclear-weapons programme.
The more sedate approach follows "common sense", says Ricardo Betti, a physicist at the University of Rochester in New York. But he worries that the plan does not give enough time to ignition experiments, focusing instead on other nuclear-weapons experiments and fundamental science. Devoting less time to ignition reduces the probability of success, he warns...
http://www.nature.com/news/laser-fusion-put-on-slow-burn-1.12016
http://www.nature.com/polopoly_fs/7.7875!/file/Report%20to%20Congress-NIF%20Path%20Forward-December%207%202012.pdf
The US National Ignition Facility rethinks its strategy on achieving thermonuclear fusion in the lab, but fails to silence critics.
Geoff Brumfiel
Nature
11 December 2012
The government's new plan, revealed to Nature, calls for a slower, more deliberate approach to achieving ignition: the point at which more energy is produced by a fusion reaction than is consumed. Many physicists believe that this would be an important proof of concept for controlled fusion.
The plan sets a new course for the laser at the National Ignition Facility at the Lawrence Livermore National Laboratory in California. It also promotes the exploration of several alternative ways to reach ignition, including one not involving the laser. And it is more tentative than the previous strategy: it sets a three-year deadline for finding out whether ignition is possible at all, whereas the last one aimed to demonstrate actual fusion...
The US$3.5-billion NIF uses lasers to crush a 2-millimetre pellet of hydrogen fuel to the point of fusion. Rather than irradiating the fuel directly, the lasers shine into a cylindrical capsule. The capsule walls then emit X-rays that squeeze the fuel pellet until it explodes.
This indirect approach mimics the ignition system in a thermonuclear weapon, which uses radiation from a fission 'primary' stage to squeeze hydrogen isotopes in the fusion 'secondary' — creating a powerful explosion.
The NIF's main mission is to gather laboratory data on the process to help weapons scientists to care for the ageing US nuclear stockpile. The United States has adhered to a voluntary moratorium on testing nuclear weapons since 1992, so nuclear scientists must use computer simulations to check that the weapons still work, and NIF data feed into these models.
Physicists at the NIF also hope that the process might pave the way for producing electrical power through thermonuclear fusion.
The latest plan was drafted by the NNSA, which oversees the lab, in response to a congressional request for a strategy for achieving ignition.
Over the next three years, researchers will conduct reduced-power tests to refine their computer simulations and understand why ignition has been so elusive. They will also look at possible improvements to the capsule design.
Other promising approaches to be studied include using lasers to ignite the hydrogen fuel inside the pellet directly, and using a machine called the Z-pinch to squeeze the fuel inside a magnetic field.
By October 2015, the NNSA hopes, it will be able to say whether ignition can be achieved using the NIF or the Z-pinch. Failure, it warns, could have serious implications for the nuclear-weapons programme.
The more sedate approach follows "common sense", says Ricardo Betti, a physicist at the University of Rochester in New York. But he worries that the plan does not give enough time to ignition experiments, focusing instead on other nuclear-weapons experiments and fundamental science. Devoting less time to ignition reduces the probability of success, he warns...
http://www.nature.com/news/laser-fusion-put-on-slow-burn-1.12016
http://www.nature.com/polopoly_fs/7.7875!/file/Report%20to%20Congress-NIF%20Path%20Forward-December%207%202012.pdf
Comments
The question is not whether NIF should survive or not. The question is whether NIF should be funded at its current level considering that diverting funds to other facilities will obviously produce more "bang for the buck."
Additionally, this report indeed confirms the "blank check" approach that NIF is being allowed to follow. The strategies to investigate issues regarding ignition are clear for Z and Omega. However, continuing the Edisonian approach towards ignition on the most expensive experiments on NIF on a per-shot basis is simply irresponsible. However, this is essentially what the report is saying. If NIF is "that" close to reaching ignition, then the last 6 months of intense investigation would have yielded some indicator of progress or greater understanding. Since it has not, but instead, opened up more questions, it indicates the need to shift (as the report correctly states) to a more slower methodical approach, and that naturally favors lower-cost Omega and Z as the workhorses and key platforms for NNSA's ignition mission moving forward.
This NNSA report to congress is incomplete for this fact - that the capability supply across the different platforms does not match the capability demand articulated by the technical review committee in their own findings used in this report. In addition, the value of each capability is not just based on the amount of energy it can put into each shot, but also on the quality of the scientific products generated from the shots, and therefore the quality of scientists themselves. Past scientific accomplishments is a reliable indicator for future scientific endeavors to generate quality scientific contributions. As such, the report clearly does not address these other very important factors across the various facilities and platforms.
Unless the thinking by congress and NNSA is for NIF to continue as a "welfare program" for weapons scientists, it is clear that the facility must cut its costs through a reduced operating schedule, reduced numbers of shots, and reduced numbers of FTEs. One does not have to advocate preventing scientific research on the platform. However, far too much resources are being misallocated to NIF, when much of that funding will produce better understanding, and improve the likelihood of resolving questions and issues surrounding ignition within the 3 year time horizon.
December 12, 2012 2:15 PM
Delete
My opinion.
I wonder when those in Washington DC are going to wake up and use the American tax payers money where it need to in order to get us off fossil fuel, make jobs and build things we know how to do, all of which would cure our problems when it comes to electricity production. I’m so tired of watching people being manipulate by those in high places with their BS sob stories of, “can’t you please give us another chance”, in this case three more years, while we as a nation fall further and further behind in achieving our goal of total independent from fossil fuel used for power production. We’ve had forty years of R&D laser research to accomplish this mission and we’ve failed, so what makes you think we’ll accomplish it in the next three? It’s absolutely sad to see our tax dollars being spent on all the wrong tooIs / projects. I personally don’t give a hoot what all the wizz kids say about how wind power, sea power, geothermal plants and solar arrays aren’t efficient enough. The simple fact is this. If you build all of these power producing apparatuses and wire them all into our national power grid we’ll be doing far better than what we are now, plus, you’ll make jobs for millions of people for their entire lives maintaining them, not taking into account retrofits and upgrade. So go blow your smoke us someone else butt. Get the job done booze’s and stop giving money out to project that live on hopes and dreams. Do what you know how to do and tell the oil companies to stick it where the sun doesn’t shine.
Good luck and don't wait until the last minute! They'll be plenty of smart people trying to get out and snag what good jobs they can before you make your move through the front door.
Besides, anyone who is dumb enough to stay around NIF to the bitter end will be sandbagged with all the blame. That won't be fun, will it?
But NIF did provide important lessons - that this is the kind if problem you will run into in big science when you have zero margin. Unfortunately this lack of margin was known well in advance, and many critics had been pounding away at the design for this very reason. These critics were ignored, and now we have an impotent 6B facility.
If you see a NIF poster, you should carefully roll it up loosely with acid free paper and keep it in a dry environment. You should remove finger oil smudges only if it can be done withou damaging the printing. Also creases will devalue a poster. Pinholes on corners will devalue the poster slightly. If there are pristine copies that are about to be thrown out, then you may have hit the jackpot.
Other memorabilia can have some limited value in the future, like NIF mugs and polo shirts. Letterheads and pens usually have no collectible value.
Posters are the likely to have the best collectible value appreciation. If you have a chance, you should try to get your hands on NIF posters. You can request them through the program office, and may even begin enjoying them immediately in your home.
Will somebody just kill this thing already.
Why do people use these phrases in context that argues the opposite.
That is "bloody obvious" isn't.
NIF has been operation doing ignition experiments for about a year. Prior to that, no existing experimental apparatus could get pressures within 100x of what now are regularly achieved.
The tool finally exists to explore scientific regime. So it seems wise to explore it.
Course I'm not competing for funds with NIF. Just saying, motives count.
again, bombast contradicted by fact.
It is bloody obvious. You people have been in Edisonian mode for the last 9 months. You guys have no clue. Your neutron yields get worse with your little fixes. And we absolutely know that you have no margin.
So indeed it is BLOODY OBVIOUS. NIF = Fail. Moses = Fail. Target design team = FAIL
You have a small mind me thinks.
People remember Ceaser they do not remember who wrote the graffiti. One like you still throws stones at the moon. Science marches on by doing the experiment and it has always been thus. I will give you credit it is of some amusement to see children throw rocks at the moon, but after awhile it gets boring. You are now boring.
Do the experment...study the realm!
These are the realms that LLNL scientists need to study. The realm of why their work is so bad and why they keep promoting the people behind it, or even people who have no business running experimental groups.
That NIF memorabilia will be a collectible some day for this exact reason. Think: old soviet era propaganda posters.
December 15, 2012 9:40 AM
This is no longer an experiment! There is no experiment without a hypothesis.
Utubes:
http://www.youtube.com/watch?v=DyB7Ho_W9RE
Bumbling . . .
This is how the story ends. If NNSA wanted to save the lab, it would have shut down NIF and integrated llnl work at nts. But to instead get 3 years of feasibility where all of the investigations are focused on omega and Z tells you that 3 years is the time allotted for Ed and NIF to completely destroy itself. The technical leads have no place to go, they have no credibility outside the lab so the lab can count on them to be there until the end and to keep applying Edisonian science until their own grave has been dug. They will get what's coming to them. It's just too bad that good scientists and good programs have to take a beating through all of this.
December 16, 2012 10:35 AM
Man you guys at LLNL have a great reputation of grooming greedy egotistical folks that destroy scientists and engineers and the ultimately try to take the Labs down with them.
Lowell Wood, Ed Moses, Mike Anastasio, Brett Knapp, Charlie McMilan, to name a few.....
It's what is wrong with the Labs, don't work there....
Is the current ignition problems of a similar nature and would academic and industrial engagement help at all as it did with the optical damage? I heard that there were a number of workshops to deal with the issue, but heard very little about outcomes or straw man hypotheses.
December 17, 2012 2:26 AM
As you can tell from the responses on this, our scientists at the National Labs can't even come up with a viable explanation, let alone articulate it. It's no wonder NIF is sinking.
This blog instead is about malcontents, retirees, foreign intelligence service propoganda and looky-loos. Oh yeah, two arm-chair Nobellaureates from New Mexico.
I have to say... The level of hubris shown by lab management is simply unwarranted given the string of failures. And please stop repeating over and over how your NIF build was great? It's obvious theat you say that because you have no really good scientific findings to brag about from NIF, but please, the repetition is getting annoying. And stop peddling that RT material strength crap, that is not science.
The people at the lab certainly pay attention to what's here, especially when it's dirty laundry being aired for everyone to see
Baloney. Can't even get a good explanation of optics damage. This blog is read by precocious high-school malcontents, oh yeah and Parney.
My guess is this loolapalooza is from a junior propoganda officer at Lop Nor, practicing English and shit-disturbing at the same time.
Merry Christmas to you Mr. Wong. Oh, that's right, you are godless.
Well then, happy hummingbirds to you.
NIF is operating as designed.
Ignition and defense science studies are underway.
All is well.
I have a bunch of Shiva collectables if anyone is interested.
or at least, NNSA.