6 ms·

Momentary fusion breakthroughs face hard reality

104 points by mfiguiere 3y ago

twp 3y ago
There's a really good series on what's needed to build a working fusion reactor on the YouTube channel "Improbable Matter". How nuclear fusion works (1) - fusors, thermonuclear reactions, lattice fusion: https://www.youtube.com/watch?v=2DzKXN1pcwY https://www.youtube.com/watch?v=2DzKXN1pcwY How nuclear fusion works (2) - confinement, stars, nukes, inertial fusion energy: https://www.youtube.com/watch?v=mxmxZI2Ltvs https://www.youtube.com/watch?v=mxmxZI2Ltvs How nuclear fusion works (3) - magnetic confinement, tokamaks, stellarators: https://www.youtube.com/watch?v=gwOrbr8KWDs https://www.youtube.com/watch?v=gwOrbr8KWDs How nuclear fusion (maybe) works (4) - reactor practicalities: https://www.youtube.com/watch?v=ZHmHBMaS6Sw https://www.youtube.com/watch?v=ZHmHBMaS6Sw Strongly recommended!
- wolverine876 3y ago
  Who makes "Improbably Matter"?
rob74 3y ago
> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s fuel pellets are also extremely expensive, says Kritcher, each one pricing in at an estimated $100,000. Then, producing a reasonable amount of power would mean dramatically increasing the frequency of NIF’s shots — a feat barely on the horizon for a reactor that requires months to load up the next nanosecond-long burst. "months to load up" is even a euphemism - IIRC they have to repair parts of the lasers which are so overpowered that they damage their guidance optics with each blast. So the cost for one shot is even higher than the $100,000 for the fuel pellet and the cost of the energy consumed by the lasers. I wonder why everyone skirts around the obvious here: the NIF's task is weapons research, and for that, fusion reactions which last nanoseconds might be enough, but there is no way this method can be scaled up so it's actually a cost-effective way of producing electricity...
- SigmundA 3y ago
  >I wonder why everyone skirts around the obvious here: the NIF's task is weapons research, and for that, fusion reactions which last nanoseconds might be enough, but there is no way this method can be scaled up so it's actually a cost-effective way of producing electricity... We already have fusion weapons that work very well, there is some valuable data that can aid weapons design I don't believe that to be a primary goal here. Looks like they did shift to plutonium targets for a while about a decade ago focusing more on weapons research but then shifted back to trying to work toward controlled ignition for power generation. Still a long way to go but the first step is getting more energy out then in on the main reaction without using fission bombs and destroying the device. Then figure how to scale up to get more energy out than in when considering the apparatuses efficiency, then getting more out than in when considering heat engine efficiency.
  - FourHand451 3y ago
    I think you may be slightly misinterpreting the parent comment. When they say the NIF's task is weapons research, I think they meant that the facility was built with that task in mind. When I read your comment it sounds more like you're talking about the current task of the people working there. Both valid points of discussion, but different ones.
- gene-h 3y ago
  NIF uses inefficient lasers because they were cheap to build at the time and because NIF is a science experiment. Lasers have gotten better. And lasers aren't the only way ICF fusion could be carried out, it may be possible to use ion beams instead[0]. It does not matter if fusion reactions last microseconds if they generate more energy. Using optimistic, but not unrealistic assumptions, it appears feasible for electricity costs to reach $25 per MWh[1] with ICF. With the most important factors driving cost being achieving high gain and yield per shot [0]https://ieeexplore.ieee.org/document/650904/ https://ieeexplore.ieee.org/document/650904/ [1]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.0053 https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...
  - 3y ago
1970-01-01 3y ago
..using the laser approach. Other approaches don't have that issue: https://www.iaea.org/newscenter/news/tokamaks-stellarators-laser-based-and-alternative-concepts-report-offers-global-perspective-on-nuclear-fusion-devices https://www.iaea.org/newscenter/news/tokamaks-stellarators-l...
- rob74 3y ago
  I guess that's why they're using "Momentary Fusion" in the title? Of course, it wouldn't have hurt to mention in the article that other approaches which might be more feasible also exist...
  - zug_zug 3y ago
    Well those of us who have never heard of "momentary fusion" read the title to mean "momentary breakthroughs in fusion"
  - Manabu-eo 3y ago
    I never heard the term "Momentary Fusion". There are other pulsed fusion methods, like Dense Plasma Focus[1] with it's very hot but very short lived plasmoids. Also still far from being economically viable, but I would say has a much better chance than that weapon research on NIF[2]. [1] https://en.wikipedia.org/wiki/Dense_plasma_focus https://en.wikipedia.org/wiki/Dense_plasma_focus [2] https://spectrum.ieee.org/startup-lppfusion-embraces-instability https://spectrum.ieee.org/startup-lppfusion-embraces-instabi...
- dukoid 3y ago
  My bets are on Wendelstein 7-X / Stellarators
deleted 3y ago
[deleted]
gene-h 3y ago
The work from Rochester mentioned briefly is probably the second best performing fusion experiment and this was done with a laser that's at least 29 years old. What the article doesn't mention is that the approach demonstrated could decrease the cost of fuel pellets. In NIF, the laser energy is converted to X-rays which compress the fuel pellet using expensive elements like gold. What they demonstrated is that the fuel pellet can be imploded directly with the lasers.
_a_a_a_ 3y ago
OT but are there any links to resources about using fission/fusion bombs directly for energy production?
- philipkglass 3y ago
  The concept was explored in the United States as Project PACER: https://en.wikipedia.org/wiki/Project_PACER https://en.wikipedia.org/wiki/Project_PACER
  - _a_a_a_ 3y ago
    excellent, thanks
- wolverine876 3y ago
  Why go through the expense of engineering and manufacturing a bomb, and then use it for a different purpose? If you want an electricity generator, engineer and manufacture for that. Or are you thinking of using excess bombs? I want to say that fusion bombs require more energy input than they output, because until recently nobody has been able to create fusion reactions otherwise (and now only in a very limited way). But is that true? Fusion bombs release an incredible amount of energy. Maybe it's that they release it all at once, but still, how does that equation work out?
  - _a_a_a_ 3y ago
    > Why go through the expense of... Good question. I should have asked strictly about fusion bombs. These being a known-working example of energy production by fusion, why not use them when we can't get 'controlled' fusion working?
    - thmsths 3y ago
      From my recollection, even in a fusion bomb, most of the energy comes from the fission. I don't fully remember/understand the physics involved. But apparently the fission reaction triggers the fusion reaction (that part I get) and then that fusion reaction in turns boosts the fission reaction. So my takeaway is that fission bombs are not very efficient to begin with. You're after all trying to extract as much energy as possible as quickly as possible from a system that is literally self destructing. We do not have that constraint with current fission plants, the plant is designed to run in a steady state for years, the fissile materials stay in place and my intuition is that this significantly helps efficiency.
deleted 3y ago
[deleted]
gentleman11 3y ago
Imagine a second Manhattan Project, except this time, it's to produce fusion energy and try to save the world from climate disasters instead of making a weapon. Who would you tap to participate in/lead this?
- throwaway44023 3y ago
  Elon Musk and his ability to gather financing and top engineers
  - astrange 3y ago
    Better get him to rehab first.
- killingtime74 3y ago
  Oppenheimer again
- Karellen 3y ago
  Why do you think finishing the fusion research (just another 10 years? again?), and then designing commercial reactors, and then building out all the fusion generation capacity we need, could possibly take less time/money/effort than just building out all the wind/solar/battery capacity instead, which we already know how to make?
  - m463 3y ago
    I think it's a good strategy to have alternate energy sources. We use energy in so many ways, we should also generate it in many ways too. We should develop a portfolio of energy sources. Yes, the top ways might be solar, wind, batteries. But what if we need energy at night during cold weather without wind? We will continue to burn giant oil tankers full of fossil fuels. Looking back, the outlook for Solar PV in president carter era seemed just about as unsatisfying as fusion is now. I also think fission should get some predictable sustained research funding, and political will to make it a part of the picture, but safe and modern.
AtlasBarfed 3y ago
I don't think fusion will ever be cheaper than solar and wind
- KiwiJohnno 3y ago
  No, but it will be more reliable, and potentially portable. Both very important characteristics. I do agree that distributed solar and wind (with battery storage) can take take care of grid base load, but that doesn't mean fusion is pointless.
gregfjohnson 3y ago
A new fusion company name Blue Laser Fusion is working on inertial fusion with new laser technology. Does anyone have information on what they are doing, and what the prognosis is for that company's approach?

104 points by mfiguiere 3y ago

twp 3y ago

There's a really good series on what's needed to build a working fusion reactor on the YouTube channel "Improbable Matter". How nuclear fusion works (1) - fusors, thermonuclear reactions, lattice fusion: https://www.youtube.com/watch?v=2DzKXN1pcwY https://www.youtube.com/watch?v=2DzKXN1pcwY How nuclear fusion works (2) - confinement, stars, nukes, inertial fusion energy: https://www.youtube.com/watch?v=mxmxZI2Ltvs https://www.youtube.com/watch?v=mxmxZI2Ltvs How nuclear fusion works (3) - magnetic confinement, tokamaks, stellarators: https://www.youtube.com/watch?v=gwOrbr8KWDs https://www.youtube.com/watch?v=gwOrbr8KWDs How nuclear fusion (maybe) works (4) - reactor practicalities: https://www.youtube.com/watch?v=ZHmHBMaS6Sw https://www.youtube.com/watch?v=ZHmHBMaS6Sw Strongly recommended!

wolverine876 3y ago
Who makes "Improbably Matter"?

rob74 3y ago

> Plenty of other obstacles remain than those noted above, too. Current calculations compare energy generated against the NIF laser’s output, but that brushes over the fact that the lasers draw more than 100 times the power from the grid than any fusion reaction yields. That means either energy gains or laser efficiency would need to improve by two orders of magnitude to break even in any practical sense. The NIF’s fuel pellets are also extremely expensive, says Kritcher, each one pricing in at an estimated $100,000. Then, producing a reasonable amount of power would mean dramatically increasing the frequency of NIF’s shots — a feat barely on the horizon for a reactor that requires months to load up the next nanosecond-long burst. "months to load up" is even a euphemism - IIRC they have to repair parts of the lasers which are so overpowered that they damage their guidance optics with each blast. So the cost for one shot is even higher than the $100,000 for the fuel pellet and the cost of the energy consumed by the lasers. I wonder why everyone skirts around the obvious here: the NIF's task is weapons research, and for that, fusion reactions which last nanoseconds might be enough, but there is no way this method can be scaled up so it's actually a cost-effective way of producing electricity...

SigmundA 3y ago
>I wonder why everyone skirts around the obvious here: the NIF's task is weapons research, and for that, fusion reactions which last nanoseconds might be enough, but there is no way this method can be scaled up so it's actually a cost-effective way of producing electricity... We already have fusion weapons that work very well, there is some valuable data that can aid weapons design I don't believe that to be a primary goal here. Looks like they did shift to plutonium targets for a while about a decade ago focusing more on weapons research but then shifted back to trying to work toward controlled ignition for power generation. Still a long way to go but the first step is getting more energy out then in on the main reaction without using fission bombs and destroying the device. Then figure how to scale up to get more energy out than in when considering the apparatuses efficiency, then getting more out than in when considering heat engine efficiency.
- FourHand451 3y ago
  I think you may be slightly misinterpreting the parent comment. When they say the NIF's task is weapons research, I think they meant that the facility was built with that task in mind. When I read your comment it sounds more like you're talking about the current task of the people working there. Both valid points of discussion, but different ones.
gene-h 3y ago
NIF uses inefficient lasers because they were cheap to build at the time and because NIF is a science experiment. Lasers have gotten better. And lasers aren't the only way ICF fusion could be carried out, it may be possible to use ion beams instead[0]. It does not matter if fusion reactions last microseconds if they generate more energy. Using optimistic, but not unrealistic assumptions, it appears feasible for electricity costs to reach $25 per MWh[1] with ICF. With the most important factors driving cost being achieving high gain and yield per shot [0]https://ieeexplore.ieee.org/document/650904/ https://ieeexplore.ieee.org/document/650904/ [1]https://royalsocietypublishing.org/doi/10.1098/rsta.2020.0053 https://royalsocietypublishing.org/doi/10.1098/rsta.2020.005...
- 3y ago

1970-01-01 3y ago

..using the laser approach. Other approaches don't have that issue: https://www.iaea.org/newscenter/news/tokamaks-stellarators-laser-based-and-alternative-concepts-report-offers-global-perspective-on-nuclear-fusion-devices https://www.iaea.org/newscenter/news/tokamaks-stellarators-l...

rob74 3y ago
I guess that's why they're using "Momentary Fusion" in the title? Of course, it wouldn't have hurt to mention in the article that other approaches which might be more feasible also exist...
- zug_zug 3y ago
  Well those of us who have never heard of "momentary fusion" read the title to mean "momentary breakthroughs in fusion"
- Manabu-eo 3y ago
  I never heard the term "Momentary Fusion". There are other pulsed fusion methods, like Dense Plasma Focus[1] with it's very hot but very short lived plasmoids. Also still far from being economically viable, but I would say has a much better chance than that weapon research on NIF[2]. [1] https://en.wikipedia.org/wiki/Dense_plasma_focus https://en.wikipedia.org/wiki/Dense_plasma_focus [2] https://spectrum.ieee.org/startup-lppfusion-embraces-instability https://spectrum.ieee.org/startup-lppfusion-embraces-instabi...
dukoid 3y ago
My bets are on Wendelstein 7-X / Stellarators

deleted 3y ago

[deleted]

gene-h 3y ago

The work from Rochester mentioned briefly is probably the second best performing fusion experiment and this was done with a laser that's at least 29 years old. What the article doesn't mention is that the approach demonstrated could decrease the cost of fuel pellets. In NIF, the laser energy is converted to X-rays which compress the fuel pellet using expensive elements like gold. What they demonstrated is that the fuel pellet can be imploded directly with the lasers.

_a_a_a_ 3y ago

OT but are there any links to resources about using fission/fusion bombs directly for energy production?

philipkglass 3y ago
The concept was explored in the United States as Project PACER: https://en.wikipedia.org/wiki/Project_PACER https://en.wikipedia.org/wiki/Project_PACER
- _a_a_a_ 3y ago
  excellent, thanks
wolverine876 3y ago
Why go through the expense of engineering and manufacturing a bomb, and then use it for a different purpose? If you want an electricity generator, engineer and manufacture for that. Or are you thinking of using excess bombs? I want to say that fusion bombs require more energy input than they output, because until recently nobody has been able to create fusion reactions otherwise (and now only in a very limited way). But is that true? Fusion bombs release an incredible amount of energy. Maybe it's that they release it all at once, but still, how does that equation work out?
- _a_a_a_ 3y ago
  > Why go through the expense of... Good question. I should have asked strictly about fusion bombs. These being a known-working example of energy production by fusion, why not use them when we can't get 'controlled' fusion working?
  - thmsths 3y ago
    From my recollection, even in a fusion bomb, most of the energy comes from the fission. I don't fully remember/understand the physics involved. But apparently the fission reaction triggers the fusion reaction (that part I get) and then that fusion reaction in turns boosts the fission reaction. So my takeaway is that fission bombs are not very efficient to begin with. You're after all trying to extract as much energy as possible as quickly as possible from a system that is literally self destructing. We do not have that constraint with current fission plants, the plant is designed to run in a steady state for years, the fissile materials stay in place and my intuition is that this significantly helps efficiency.

deleted 3y ago

[deleted]

gentleman11 3y ago

Imagine a second Manhattan Project, except this time, it's to produce fusion energy and try to save the world from climate disasters instead of making a weapon. Who would you tap to participate in/lead this?

throwaway44023 3y ago
Elon Musk and his ability to gather financing and top engineers
- astrange 3y ago
  Better get him to rehab first.
killingtime74 3y ago
Oppenheimer again
Karellen 3y ago
Why do you think finishing the fusion research (just another 10 years? again?), and then designing commercial reactors, and then building out all the fusion generation capacity we need, could possibly take less time/money/effort than just building out all the wind/solar/battery capacity instead, which we already know how to make?
- m463 3y ago
  I think it's a good strategy to have alternate energy sources. We use energy in so many ways, we should also generate it in many ways too. We should develop a portfolio of energy sources. Yes, the top ways might be solar, wind, batteries. But what if we need energy at night during cold weather without wind? We will continue to burn giant oil tankers full of fossil fuels. Looking back, the outlook for Solar PV in president carter era seemed just about as unsatisfying as fusion is now. I also think fission should get some predictable sustained research funding, and political will to make it a part of the picture, but safe and modern.

AtlasBarfed 3y ago

I don't think fusion will ever be cheaper than solar and wind

KiwiJohnno 3y ago
No, but it will be more reliable, and potentially portable. Both very important characteristics. I do agree that distributed solar and wind (with battery storage) can take take care of grid base load, but that doesn't mean fusion is pointless.

gregfjohnson 3y ago

A new fusion company name Blue Laser Fusion is working on inertial fusion with new laser technology. Does anyone have information on what they are doing, and what the prognosis is for that company's approach?