4 ms·

NIF didn't have anything even remotely practical though. The energy loss in the lasers alone is game over.

• Y_Y 3y ago
  Exactly. They showed that it's a very lofty target even for a collosal non-commercial effort.
• itishappy 3y ago
  It's a fair critique, but it was also never the intent. It was designed to test nuclear physics, not generate power.
  • cameldrv 3y ago
    It’s a reasonable misunderstanding though. They pretty deliberately obscure this fact.
    • itishappy 3y ago
      I think they've been quite clear on their goals and accomplishments. Do you have an example in mind?
      • boxed 3y ago
        The big press releases claiming it has implications for fusion?
        • itishappy 3y ago
          This one? https://www.llnl.gov/article/49301/shot-ages-fusion-ignition-breakthrough-hailed-one-most-impressive-scientific-feats-21st https://www.llnl.gov/article/49301/shot-ages-fusion-ignition... What do you find misleading? The ability to study self sustaining fusion reactions without nukes certainly does have implications for fusion, which aligns with their stated goals of researching nuclear physics.
          • throwawaymaths 3y ago
            What is misleading is that nowhere in the press release do they say: 1) this research is weapons research (much less primarily weapons over power research) 2) this research does not currently contend a viable avenue towards breakeven power generation
            • itishappy 3y ago
              > DOE Under Secretary for Nuclear Security and NNSA Administrator Jill Hruby said in achieving ignition, LLNL researchers have “opened a new chapter in NNSA’s science-based Stockpile Stewardship Program,” one that enables scientists to modernize nuclear weapons and explore new avenues of research in nuclear science. > Following Hruby, NNSA Deputy Administrator for Defense Programs Marvin “Marv” Adams showed a NIF target capsule and explained the science behind fusion reactions. Adams said ignition will enhance national security by helping NNSA maintain confidence in the nuclear deterrent, advance the country’s non-proliferation goals and increase national security. > “The science and technology challenges on the path to fusion energy are daunting but making the seemingly impossible possible is when we're at our very best,” Budil explained. “Ignition is a first step — a truly monumental one that sets the stage for a transformational decade in high energy density science and fusion research — and I cannot wait to see where it takes us.” > While optimism reigned for the event, Budil cautioned there are still “significant hurdles” and engineering challenges to solve before the commercialization of fusion energy becomes a reality, such as the ability to reproduce ignition many times per minute and making fusion reactions simpler and more efficient. > “I think it's moving into the foreground and, probably with concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant,” Budil said.
              • throwawaymaths 3y ago
                > the seemingly impossible possible Did anyone seriously believe it was impossible to get "q" > 1 fusion by blasting a pellet of hydrogen hard enough? --- Significant hurdles != "There is not currently a/no known path" I'm still toning down from "a path is impossible" which ought to be the consensus. > a few decades of research on the underlying technologies could put us in a position to build a power plant No.
      • throwawaymaths 3y ago
        Since we're on the topic of "dragging in big funding based on the dream of fusion", can you point to a press release where they explicitly mention that this research is for weapons research and not for power research?
        • itishappy 3y ago
          Have you checked their website? > MAINTAINING THE NUCLEAR DETERRENT > Stockpile Stewardship > NIF is a key element of the National Nuclear Security Administration’s science-based Stockpile Stewardship Program to maintain the reliability, security, and safety of the U.S. nuclear deterrent without full-scale testing. https://lasers.llnl.gov/about/what-is-nif https://lasers.llnl.gov/about/what-is-nif > For more than 70 years, Lawrence Livermore National Laboratory has applied science and technology (S&T) to make the world a safer place. While keeping our crucial mission-driven commitments in mind, we apply cutting-edge science and technology to achieve breakthroughs in nuclear deterrence, counterterrorism and nonproliferation, defense and intelligence and energy and environmental security. https://www.llnl.gov/ https://www.llnl.gov/ It's also intended for energy research, but there's an important distinction between "energy research" and "energy production."
          • throwawaymaths 3y ago
            Website != Press release
            • firedaemon 3y ago
              At this point the claim seems to be but I think that some people think it is all about energy, as if your random interpretation of other peoples’ belief is relevant. They do weapons. They said they do weapons. What’s the problem.
              • throwawaymaths 3y ago
                They don't say that in their press releases. None of the popular media coverage talks about the weapons aspect, much less that it's primary. I challenge you to prove me wrong. The general public is not stupid (but they are lazy), when the dust settles and people see that nif never resulted in anything but very tangential results useful for power, they're going to complain about the lack of transparency. Just as they are doing with the whole COVID masking debate. Scientists really dig their own graves sometimes.
• ben_w 3y ago
  IIRC, that specific issue is merely an implementation detail, much more efficient lasers already exist. There are plenty of other problems to be solved, and a lot of room for higher gain — upgrading the lasers isn't worth caring about until those things have actually been done.
  • boxed 3y ago
    The efficiency in the lasers isn't off by 50%. They are off by SEVERAL orders of magnitude. Plus the fuel pellets are too expensive anyway.
    • ben_w 3y ago
      Yes, I know. NIF's lasers are, I'm told, less than 1% efficient; modern lasers can be 50%-80% if that's what is being optimised for. There's no reason to bother upgrading those lasers until all the other issues are solved, and even then, as it's an experimental facility not a power station, they may well never bother even if it is the only thing holding them back from a gain of more than 1 as measured wallplug-to-wallplug.
• maxcan 3y ago
  True. But if you replace the Hohlraum with dilithium and find an anti-matter supply you can power a warm drive for FTL travel. Just need to kick it now and then.
• DennisP 3y ago
  They lose so much in the lasers because they're using lasers from the 1990s, which are only 0.5% efficient. Equivalent modern lasers are over 20% efficient. From the input power being 130X more than the fusion output, modern lasers would turn that into about 3X. That's kinda promising because the fusion output seems to have nonlinear scaling; they increased laser power 8% and got 230% more output. This is why there are startups now pursuing laser fusion for commercial energy.