12 ms·

Lawrence Livermore NIF laser fusion experiment delivers record energy output

35 points by UnFleshedOne 13y ago

chaosphere2112 13y ago
Link to the original press release: https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04.html https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04....
quanticle 13y ago
Did this get a positive energy return? If I've understood past ignition attempts correctly, they too delivered tremendous energy output... but required even more tremendous energy input.
- throwaway_yy2Di 13y ago
  No, it's extremely negative. "In the nanoseconds that followed, the capsule imploded and released a neutron yield of nearly 3x10^15, or approximately 8,000 joules of neutron energy..." [...] "These promising returns were the result of a laser experiment that delivered 1.7 megajoules (MJ or million joules) of ultraviolet light..." More numbers: https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF_and_ICF https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...
  - nonce42 13y ago
    To put these numbers in context, 8000 joules is about 2 kilocalories (or about half an M&M candy). It's about $0.0003 of wall electricity. It's about the energy in an AA battery. It's the energy from exploding 2 grams of TNT. 1.7 megajoules is about 400 kilocalories, or a king size Kit Kat bar. This is the energy of a car going 140 miles per hour. This is about 7 cents of AC power.
    - PhasmaFelis 13y ago
      "...about 400 kilocalories, or a king size Kit Kat bar. This is the energy of a car going 140 miles per hour." Wow. How can those two things be equivalent? I know there's a lot I don't know about physics...
      - Florin_Andrei 13y ago
        Kinetic energy is the speed, squared, times the mass, halved. 140 mph is not a small number; to the power of two it's rather large. Now multiply the result by the mass of a car, which is still pretty huge even halved. A racing car barreling down the speedway packs a hell of a punch.
        StavrosK 13y ago
        I think the GP's question was more like "how the hell can a single Kit Kat bar get a whole car to 140 mph?".
        Florin_Andrei 13y ago
        I see. Well, a kitkat bar actually has a decent amount of energy in it. Very roughly, the same energy as the same mass of wood, or gasoline. Chemical fuels don't vary too much in terms of energy density. They stay within the same order of magnitude, at most. And yes, food is chemical fuel.
        maaku 13y ago
        No, a Kit Kat bar has way more energy per gram than wood, or even TNT. A king size Kit Kat bar packs basically the same energy as 0.5kg of TNT. That's a lot of power. Probably only a straight-up chemical fuel like gasoline or methane packs more punch per gram.
        gus_massa 13y ago
        Strange. I did some research and found some numbers. The energy density of Kit Kat is 22 MJ/Kg (5.2 Kcal/g) http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+megajoules%29+%2F+%28Kit+Kat+weight+to+kilograms%29 http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+... TNT has 2.8 MJ/Kg in an explosion and 4.2 MJ/Kg in a combustion. It has too much Carbons. In an explosion, it doesn’t react with the oxygen in the air, because it’s too fast. There is an interesting discussion in http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content In general, the explosives have to explode without using the Oxygen in the air, so they have a lot of Oxygen and Nitrogen atoms inside. The fuels for slow combustions can have almost only Carbon and Hydrogen atoms to store the energy more efficiently and get the Oxygen from the air. Nitroglycerin has less Carbons, so has more energy density. Mixed in dynamite has 7.5 MJ/Kg and alone has 6.4 MJ/Kg (Is this correct? I expected a bigger value). I found a list of these values for a wide range of materials. In particular it says that green wood has 10 MJ/Kg, air dry wood has 15 MJ/Kg and oven dry wood has 20 MJ/Kg. http://physics.info/energy-chemical/ http://physics.info/energy-chemical/ Other values: Gasoline ~45 MJ/Kg, Methane 55.5 MJ/Kg, Hydrogen 142 MJ/Kg
cjensen 13y ago
NIF has been around so long that the digitizer scene in the original TRON was filmed there. Its purpose is to explore the physics of exploding nuclear weapons; it is an arm of the lab which designs US nukes. Any similarity between NIF and a practical Fusion Reactor is purely accidental.
- dlinder 13y ago
  So, first, TRON was shot in the Shiva Laser facility, a precursor to NIF that is also situated at LLNL. Second, if anyone would like to see an inspirational speech given by NIF Director Ed Moses on how you move from theory to a a working reactor based on this technology, he spoke at Long Now in SF a few years ago: http://fora.tv/2010/06/16/Ed_Moses_Clean_Fusion_Power_This_Decade http://fora.tv/2010/06/16/Ed_Moses_Clean_Fusion_Power_This_D...
  - DennisP 13y ago
    Their LIFE design for a practical, economical power plant is also worth looking at. For people who don't care about energy they've sure put a lot of work into it, in collaboration with over thirty industry vendors. https://life.llnl.gov/ https://life.llnl.gov/
- DennisP 13y ago
  That's an oversimplification. Throughout the history of laser inertial fusion in the U.S., most of the scientists involved have been keenly interested in fusion energy, and advocated a program explicitly aimed at energy production. Congress opted instead to fund it as a weapons-related program, but that doesn't mean that's all they're doing, and for a while they were explicitly spending the majority of their efforts on achieving energy gain. Recently they missed a deadline set by Congress which redirected the program to be only 20% for energy. A really great history of the U.S. fusion program, from the 1950s to about 2012, is Search for the Ultimate Energy Source by Stephen O. Dean, who was deeply involved with much of it. http://www.amazon.com/Search-Ultimate-Energy-Source-ebook/dp/B00BLR4HJ6 http://www.amazon.com/Search-Ultimate-Energy-Source-ebook/dp...
  - 13y ago
VladRussian2 13y ago
with extremely low efficiency of lasers, my bets is on Sandia Z machine. Not that these guys are in any rush to produce practical reactor as they are also mostly nuke weapons research, yet as a side effect they have been making very interesting and meaningful progress during last 15 years. The machine itself isn't for fusion research, it is for X-ray generation, and it just happens that it generates so much and so efficiently that it seems they couldn't resist and finally started trying mini Teller-Ulam :)
gwern 13y ago
I spent a bit of time over the last 3 months typing up & annotating an obscure but excellent SF/literary novel, _Radiance_ by Carter Scholz ( http://www.gwern.net/docs/2002-radiance http://www.gwern.net/docs/2002-radiance ). It's all about the Lawrence Livermore SDI scandals and then the process of them getting NIF, so I read up on the historical background. I was a little flabbergasted at the overall progress of the laser fusion research program: apparently back in the early '70s, the first LANL people predicted that you could achieve laser fusion with just 1kj of input. Millions were spent, ignition was nowhere near, so they got funding for another, bigger laser, which failed too, so they got funding for more lasers, and those failed too, so they got funding for an even bigger multi-billion dollar laser called NIF, and not only has that failed to reach ignition once as promised - despite going up to 1.7mj (quite a long way from 1kj) - LANL managed to run over budget by at least 400% and took something like a decade longer to finish NIF than promised!
- dhbradshaw 13y ago
  In the top paragraph you mention Lawrence Livermore and in the bottom one you use the acronym LANL, which is Los Alamos. Did you mean LLNL?
  - gwern 13y ago
    Yes, my bad. (They're so damn similar acronyms >.<)
contingencies 13y ago
Cultural observation: some serious govspeak interleaved with respectful capitalisation of 'Mother Nature'. (At least if the world disappears due to a crazy physics experiment one day, metaphysical archaeologist sensors in some parallel dimension who became aware of the event might see that we weren't entirely disrespectful!)
- drjesusphd 13y ago
  WTF are you talking about?
ballard 13y ago
TL;DR - 3 orders of magnitude from economic viability. in 1.7 MJ out 8 kJ Q = 0.00444_
- deleted 13y ago
  [deleted]
- drjesusphd 13y ago
  Compare that to 5 MJ output from JET, at an efficiency of 65%.
  - ballard 13y ago
    Yup. JET is delivering much than NIF, in terms of reaching the goal of maximizing Q. NIF has a program cost (1997-2013) on the order of $8B USD to reach this unimpressive number. (Based on $450m/yr not including fixed/one-time costs.) JET is in for about $20B USD ($15B €). [0] JET might be around thrice as costly, but the results speak for themselves. [0] http://www.efda.org/fusion/why-should-society-invest-in-fusion-research/cost-of-fusion-power/ http://www.efda.org/fusion/why-should-society-invest-in-fusi...
drjesusphd 13y ago
I don't know why they're even pretending anymore. Everyone knows NIF is a weapons research facility and always has been. They've milked all the PR they're going to get out of this.

35 points by UnFleshedOne 13y ago

Link to the original press release: https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04.html https://www.llnl.gov/news/newsreleases/2013/Aug/NR-13-08-04....

quanticle 13y ago

Did this get a positive energy return? If I've understood past ignition attempts correctly, they too delivered tremendous energy output... but required even more tremendous energy input.

throwaway_yy2Di 13y ago
No, it's extremely negative. "In the nanoseconds that followed, the capsule imploded and released a neutron yield of nearly 3x10^15, or approximately 8,000 joules of neutron energy..." [...] "These promising returns were the result of a laser experiment that delivered 1.7 megajoules (MJ or million joules) of ultraviolet light..." More numbers: https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF_and_ICF https://en.wikipedia.org/wiki/National_Ignition_Facility#NIF...
- nonce42 13y ago
  To put these numbers in context, 8000 joules is about 2 kilocalories (or about half an M&M candy). It's about $0.0003 of wall electricity. It's about the energy in an AA battery. It's the energy from exploding 2 grams of TNT. 1.7 megajoules is about 400 kilocalories, or a king size Kit Kat bar. This is the energy of a car going 140 miles per hour. This is about 7 cents of AC power.
  - PhasmaFelis 13y ago
    "...about 400 kilocalories, or a king size Kit Kat bar. This is the energy of a car going 140 miles per hour." Wow. How can those two things be equivalent? I know there's a lot I don't know about physics...
    - Florin_Andrei 13y ago
      Kinetic energy is the speed, squared, times the mass, halved. 140 mph is not a small number; to the power of two it's rather large. Now multiply the result by the mass of a car, which is still pretty huge even halved. A racing car barreling down the speedway packs a hell of a punch.
      - StavrosK 13y ago
        I think the GP's question was more like "how the hell can a single Kit Kat bar get a whole car to 140 mph?".
        Florin_Andrei 13y ago
        I see. Well, a kitkat bar actually has a decent amount of energy in it. Very roughly, the same energy as the same mass of wood, or gasoline. Chemical fuels don't vary too much in terms of energy density. They stay within the same order of magnitude, at most. And yes, food is chemical fuel.
        maaku 13y ago
        No, a Kit Kat bar has way more energy per gram than wood, or even TNT. A king size Kit Kat bar packs basically the same energy as 0.5kg of TNT. That's a lot of power. Probably only a straight-up chemical fuel like gasoline or methane packs more punch per gram.
        gus_massa 13y ago
        Strange. I did some research and found some numbers. The energy density of Kit Kat is 22 MJ/Kg (5.2 Kcal/g) http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+megajoules%29+%2F+%28Kit+Kat+weight+to+kilograms%29 http://www.wolframalpha.com/input/?i=%28Kit+Kat+calories+to+... TNT has 2.8 MJ/Kg in an explosion and 4.2 MJ/Kg in a combustion. It has too much Carbons. In an explosion, it doesn’t react with the oxygen in the air, because it’s too fast. There is an interesting discussion in http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content http://en.wikipedia.org/wiki/Trinitrotoluene#Energy_content In general, the explosives have to explode without using the Oxygen in the air, so they have a lot of Oxygen and Nitrogen atoms inside. The fuels for slow combustions can have almost only Carbon and Hydrogen atoms to store the energy more efficiently and get the Oxygen from the air. Nitroglycerin has less Carbons, so has more energy density. Mixed in dynamite has 7.5 MJ/Kg and alone has 6.4 MJ/Kg (Is this correct? I expected a bigger value). I found a list of these values for a wide range of materials. In particular it says that green wood has 10 MJ/Kg, air dry wood has 15 MJ/Kg and oven dry wood has 20 MJ/Kg. http://physics.info/energy-chemical/ http://physics.info/energy-chemical/ Other values: Gasoline ~45 MJ/Kg, Methane 55.5 MJ/Kg, Hydrogen 142 MJ/Kg

cjensen 13y ago

NIF has been around so long that the digitizer scene in the original TRON was filmed there. Its purpose is to explore the physics of exploding nuclear weapons; it is an arm of the lab which designs US nukes. Any similarity between NIF and a practical Fusion Reactor is purely accidental.

dlinder 13y ago
So, first, TRON was shot in the Shiva Laser facility, a precursor to NIF that is also situated at LLNL. Second, if anyone would like to see an inspirational speech given by NIF Director Ed Moses on how you move from theory to a a working reactor based on this technology, he spoke at Long Now in SF a few years ago: http://fora.tv/2010/06/16/Ed_Moses_Clean_Fusion_Power_This_Decade http://fora.tv/2010/06/16/Ed_Moses_Clean_Fusion_Power_This_D...
- DennisP 13y ago
  Their LIFE design for a practical, economical power plant is also worth looking at. For people who don't care about energy they've sure put a lot of work into it, in collaboration with over thirty industry vendors. https://life.llnl.gov/ https://life.llnl.gov/
DennisP 13y ago
That's an oversimplification. Throughout the history of laser inertial fusion in the U.S., most of the scientists involved have been keenly interested in fusion energy, and advocated a program explicitly aimed at energy production. Congress opted instead to fund it as a weapons-related program, but that doesn't mean that's all they're doing, and for a while they were explicitly spending the majority of their efforts on achieving energy gain. Recently they missed a deadline set by Congress which redirected the program to be only 20% for energy. A really great history of the U.S. fusion program, from the 1950s to about 2012, is Search for the Ultimate Energy Source by Stephen O. Dean, who was deeply involved with much of it. http://www.amazon.com/Search-Ultimate-Energy-Source-ebook/dp/B00BLR4HJ6 http://www.amazon.com/Search-Ultimate-Energy-Source-ebook/dp...
- 13y ago

VladRussian2 13y ago

with extremely low efficiency of lasers, my bets is on Sandia Z machine. Not that these guys are in any rush to produce practical reactor as they are also mostly nuke weapons research, yet as a side effect they have been making very interesting and meaningful progress during last 15 years. The machine itself isn't for fusion research, it is for X-ray generation, and it just happens that it generates so much and so efficiently that it seems they couldn't resist and finally started trying mini Teller-Ulam :)

gwern 13y ago

I spent a bit of time over the last 3 months typing up & annotating an obscure but excellent SF/literary novel, _Radiance_ by Carter Scholz ( http://www.gwern.net/docs/2002-radiance http://www.gwern.net/docs/2002-radiance ). It's all about the Lawrence Livermore SDI scandals and then the process of them getting NIF, so I read up on the historical background. I was a little flabbergasted at the overall progress of the laser fusion research program: apparently back in the early '70s, the first LANL people predicted that you could achieve laser fusion with just 1kj of input. Millions were spent, ignition was nowhere near, so they got funding for another, bigger laser, which failed too, so they got funding for more lasers, and those failed too, so they got funding for an even bigger multi-billion dollar laser called NIF, and not only has that failed to reach ignition once as promised - despite going up to 1.7mj (quite a long way from 1kj) - LANL managed to run over budget by at least 400% and took something like a decade longer to finish NIF than promised!

dhbradshaw 13y ago
In the top paragraph you mention Lawrence Livermore and in the bottom one you use the acronym LANL, which is Los Alamos. Did you mean LLNL?
- gwern 13y ago
  Yes, my bad. (They're so damn similar acronyms >.<)

contingencies 13y ago

Cultural observation: some serious govspeak interleaved with respectful capitalisation of 'Mother Nature'. (At least if the world disappears due to a crazy physics experiment one day, metaphysical archaeologist sensors in some parallel dimension who became aware of the event might see that we weren't entirely disrespectful!)

drjesusphd 13y ago
WTF are you talking about?

ballard 13y ago

TL;DR - 3 orders of magnitude from economic viability. in 1.7 MJ out 8 kJ Q = 0.00444_

deleted 13y ago
[deleted]
drjesusphd 13y ago
Compare that to 5 MJ output from JET, at an efficiency of 65%.
- ballard 13y ago
  Yup. JET is delivering much than NIF, in terms of reaching the goal of maximizing Q. NIF has a program cost (1997-2013) on the order of $8B USD to reach this unimpressive number. (Based on $450m/yr not including fixed/one-time costs.) JET is in for about $20B USD ($15B €). [0] JET might be around thrice as costly, but the results speak for themselves. [0] http://www.efda.org/fusion/why-should-society-invest-in-fusion-research/cost-of-fusion-power/ http://www.efda.org/fusion/why-should-society-invest-in-fusi...

drjesusphd 13y ago

I don't know why they're even pretending anymore. Everyone knows NIF is a weapons research facility and always has been. They've milked all the PR they're going to get out of this.