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Power

Argon Fluoride Laser Could Lead To Practical Fusion Reactors (newatlas.com) 55

The US Naval Research Laboratory (AFL) is developing an Argon Fluoride (ArF) laser that may one day make fusion power a practical commercial technology. New Atlas reports: The wide-bandwidth ultraviolet laser is designed to have the shortest laser wavelength that can scale up to power a self-sustaining fusion reaction. [...] The NRL's ArF laser is intended for a test facility based on the principle of Inertial Confinement Fusion (ICF). In this, a bead of deuterium or tritium, which are heavy isotopes of hydrogen, is fired upon by multiple lasers, heating and compressing it in a fraction of a second to such an extent that the hydrogen atoms implode, fuse together, and release enormous amounts of energy.

The new deep ultraviolet laser, also known as a laser driver, is claimed to transfer energy to the fuel bead with greater efficiency and produces much higher temperatures to generate the implosion. Using radiation hydrodynamics simulations the NRL scientists say that performance could be increased a hundredfold with an efficiency of 16 percent, compared to only 12 percent from the next most efficient krypton fluoride laser. Because of these improvements, the ArF laser could lead to smaller and less expensive fusion power plants. However, the team stresses that there is still a long way to go before fusion is hooked up to the national grid. The laser will need to provide the required energy, repetition rate, precision, and billion-shot class reliability for a practical plant.

To move towards this, the laboratory is running a three-phase program with the first dedicated to the basic science and technology of the ArF laser. This will be followed by phase two, which will concentrate on building and testing a full-scale high-energy ArF laser, and then phase three where an implosion facility consisting of 20 to 30 lasers will be constructed. "The advantages could facilitate the development of modest size, less expensive fusion power plant modules operating at laser energies less than one megajoule," says Steve Obenschain, Ph.D., a research physicist at NRL. "That would drastically change the existing view on laser fusion energy being too expensive and power plants being too large."
The research was published in the Philosophical Transactions of the Royal Society.
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Argon Fluoride Laser Could Lead To Practical Fusion Reactors

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  • by fredrated ( 639554 ) on Monday October 25, 2021 @08:47PM (#61926759) Journal

    20 years .. oh never mind.

    • performance could be increased a hundredfold with an efficiency of 16 percent, compared to only 12 percent from the next most efficient krypton fluoride laser IANAS but I take it the goal is greater than 100%. I reckon 20 years is still many decades away. Not that they shouldn't research fusion but it's gonna be lots of baby steps.

      • by jbengt ( 874751 )
        I believe they were saying a hundredfold increase in fusion performance with the laser efficiency going from 12% to 16%.
      • For a practical fusion energy system one needs the product of electrical efficiency of the plasma heating device (neutral beams for tokamaks and the laser system for laser IFE) and the fusion gain to be greater than about ten -- so that most of the electrical power goes to the grid rather than powering the systems that support the fusion power plant. Per the paper the 16% intrinsic efficiency of the ArF laser could allow 10% "wallplug" electrical efficiency -- so one needs gains (ratio of fusion energy
    • It's a standard trope for newly-discovered physical devices/systems, the rule is "$new_toy could lead to cheaper/faster/smaller/cleaner $speculative_thing", where $speculative_thing is fusion power, faster-than-light travel, monorails, space elevators, Mars colonies, teleportation, or whatever.

      In this case $new_toy is "argon fluoride laser" and $speculative_thing is "fusion reactors". Feel free to unplug/plug in anything else. I'd have set $speculative_thing="faster-than-light travel" if I'd been writing

      • It's a standard trope for newly-discovered physical devices/systems, the rule is "$new_toy could lead to cheaper/faster/smaller/cleaner $speculative_thing", where $speculative_thing is fusion power, faster-than-light travel, monorails, space elevators, Mars colonies, teleportation, or whatever.

        Yup - the interesting thing is that this new wonderlaser only helps a tiny little bit in lessening the biggest issue of fusion power.

        Parasitic energy loads.

        And this is why I consider the public facing side of fusion research - the side that wants to whip up support for spending huge amounts of money to be functionally dishonest.

        Here's my favorite physicist - Sabine Hossenfelder, dishing out a handful of truth about fusion power. https://www.youtube.com/watch?... [youtube.com]

        And let's not forget that the mantr

        • Here's my favorite physicist - Sabine Hossenfelder, dishing out a handful of truth about fusion power. https://www.youtube.com/watch [youtube.com]?... [youtube.com]

          Oooh, interesting, thanks! As she points out, I don't think the Qtotal vs. Qplasma "confusion" is accidental: Who would fund a fusion experiment if you give performance as Qtotal rather than Qplasma? So I suspect most physicists aren't overly motivated to point out that Qtotal << Qplasma.

      • a dog whistle for getting government funding for a toy
        • All truly innovative approaches to fusion are presently funded by the private sector -- e.g. MIT-Commonwealth Fusion Systems high field tokamak (smaller lower cost) -- and the General Fusion imploding liner approach -- which is based on the NRL LINUS concept from 30 years ago. The folks @ NRL may follow that route with a first of its kind path to lower cost laser IFE.
    • by Chas ( 5144 )

      To be fair, previously we were 20 years (and one hour) away!

    • by gweihir ( 88907 )

      Well, practical, reliable, industrialized fusion power never was only 20 years away. It is more like 100 at the moment. But there is steady progress, it now looks like it will work in the end and the pay-off is huge. Hence this is very much worthwhile research. You just need to ignore the utterly moronic reporting on it.

  • Clean my teeth?
    • by gweihir ( 88907 )

      It will. So well that there will not be any teeth left. Likely not even an attached head. Beat that!

  • by Anonymous Coward

    yo I already tried laser beams and toothpaste
    fused some shit cant even see outta my left eye no more

  • Yeah (Score:4, Interesting)

    by backslashdot ( 95548 ) on Monday October 25, 2021 @09:24PM (#61926837)

    This was known well before they built the NIF using the wrong kind of lasers. I remember the NRL guys being VERY pissed about it.

    References:
    https://physicstoday.scitation... [scitation.org]
    http://firefusionpower.org/Obe... [firefusionpower.org]
    https://www.researchgate.net/p... [researchgate.net]

  • Always just one more gadget out of widespread practical usability yet somehow never really ready for use in the real world. In the US we'd be better off investing in rugged/modern nuclear plant designs and then reprocessing spent fuel at a large scale.

    • Always just one more gadget out of widespread practical usability

      Really? What are you referring to with that statement?

    • In the US we'd be better off investing in rugged/modern nuclear plant designs and then reprocessing spent fuel at a large scale.

      Nuclear doesn't make sense at large scale. If you're going to reprocess spent fuel you have to plan for that spent fuel. And reprocessing fuel doesn't make economic sense, it costs a lot more than new fuel because your fuel is more dangerous than it would be in a "normal" reactor. France has been doing it, and it's raised the cost of their program dramatically... and it already costs too much. Nobody is going to spend that kind of money in order to waste that kind of money.

  • by Klaxton ( 609696 )
    An efficiency of 16%, woo. And this is just to get some amount of fusion happening. Apparently all it will take is a lot more hugely expensive lasers to focus on a very long series of little beads composed of rare materials, billions of times in quick succession. What mechanism will be able to deliver and precisely hold minute fuel pellets that go off in super-energetic fusion explosions, indefinitely? Then there will be the trivial task of figuring out how to generate electricity from it. Presumably this
    • by jbengt ( 874751 )

      An efficiency of 16%, woo.

      I read that as the efficiency of the lasers. The efficiency of the fusion power so far is negative.

      • by Klaxton ( 609696 )
        Could be, but I read it as power input (via the lasers) relative to power generated (by the fusion process). This needs to be far more than 100% just to generate enough electricity to be self-sustaining.
        • by ceoyoyo ( 59147 )

          It's electricity into the lasers versus laser power out. NIF's most recent shot was about 70% laser power into the target versus energy (not all of it capturable) out. You have to multiply 0.16 and 0.70 to get Qtotal.

      • by ceoyoyo ( 59147 )

        Negative efficiency? They've discovered how to make negative energy? Hello warp drive!

        The 16% is for the lasers. NIF fusion efficiency is likely somewhere in the neighbourhood of 10%.

        • by Klaxton ( 609696 )
          If that's the case it sounds like they are a very long way from anything practical.
          • by ceoyoyo ( 59147 )

            Yeah, they are. The laser people neglect to mention the losses in the laser, and all fusion people neglect to mention that most of the energy produced can't be used to make electricity.

            ITER is designed to produce more power (all kinds) than it uses, and maaaaybe break even on actual harvestable energy. Actually producing net harvestable energy is left to its successor though. The confined plasma type fusion people benefit from a scaling law that gives them much more efficiency for a bigger containment vesse

  • yeah, that and some fundamental new scientific theory/understanding.

    throwing endless sums of money at the old theories doesn't seem to have worked.

  • by Mal-2 ( 675116 ) on Tuesday October 26, 2021 @02:23AM (#61927343) Homepage Journal

    This fusion future sounds truly ArFL.

  • Hold up... (Score:4, Funny)

    by Gravis Zero ( 934156 ) on Tuesday October 26, 2021 @03:27AM (#61927465)

    You're missing the important bit: it can make your teeth whiter in just 30 days with new Colgate Advanced Whitening with Argon Fluoride! And for those extra tough stains, Colgate Extreme with Argon Fluoride Lasers to melt away the stains (and the rest of your molecules)!

    (toothpaste marketing has ruined the elemental name "fluoride" for my brain, probably forever)

  • How did we go half a day on a laser story without mentioning sharks???

  • Is Argon Fluoride a mixture of gasses in the lasing chamber, or is it actually a doesn't-want-to-exist Noble gas molecule?

    • by Anonymous Coward

      Looks like both, a mix until lasing by forming ArF, then splits after lasing. Wiki article has more info.

  • I mean, isn't the main problem with fusion reactors not about the energy transfer process, but rather the containment of the reaction to ensure power generation without destroying the reactor in the process? I feel like there are other ways to do this, but without a good containment system we're still at square 1.

    I could be way off; fusion is only something I've followed tangentially.

  • Is "deep ultraviolet" a thing? As near as I can tell this is ~200-280 nm which is described elsewhere as "middle ultraviolet".
  • It seems to me that if this works, the energy released by the fusion reaction is going to hit the apertures that the laser light is emitted from. This would I think destroy them in very short order. Tokomak designs at least have the energy hit a surface that does not have to be transparent, it's main limitation is that it has to be thin enough that the magnets are close enough for the device to work (there is also some kind of ports for introducing and removing fusion materials but they also seem less vulne

    • One can use transparent (to neutrons) aluminum (remember one of the Star Trek movies) grazing incidence final mirrors (GIMM) - neutrons go through (transparent Al substrate) and laser light reflects.
      • by spitzak ( 4019 )

        That sounds reasonable. Actually now that I think about it, it seems LIC has an advantage: all the neutrons are coming from the same point and in the same direction, allowing such schemes to work. It may help with whatever method is used to collect the energy, too (though as far as I can tell what this is is still pretty vague in all designs).

  • It is nice to see improvements, but we still talk about hydrogen, deuterium or tritium fusion, which produce uncontrollable neutrons.They will damage the surrounding structure, making the design unusable for real production.

    The real game changer would be hydrogen+boron fusion, which does not produce neutrons.

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