6 ms·

Major nuclear fusion milestone reached as 'ignition' triggered in a lab

174 points by dnetesn 5y ago

redis_mlc 5y ago
So ... fusion reactors are only 50 years away now? :)
mensetmanusman 5y ago
This is super exciting, but I’m still going to be more excited when it is actual ignition versus close enough ignition :) Does anyone know if they still have to wait for months to open the chamber after experiments to wait for the radioactivity to cool down?
- SiempreViernes 5y ago
  Why did they have to do that? If there's radioactive gasses to worry about contaminating something important surely they could pump those out, gotta be a good vacuum system for that chamber anyway...
  - pstch 5y ago
    In magnetic confinement reactors, the runaway neutrons collide with the reactor's shielding and can make it radioactive by neutron activation. I don't know if it's the same for inertial confinement, but I suppose it could be an explanation.
- pxhb 5y ago
  > Does anyone know if they still have to wait for months to open the chamber after experiments to wait for the radioactivity to cool down? I don’t think this has ever been the case. Note that I have been involved with experiments on the NIF, but only from the academic side. The NIF typically fires 1-3 time per day, and I believe that this is mostly an optics constraint. We weren’t producing neutrons though, so YMMV.
- avs733 5y ago
  I can’t speak to NIF but back in undergrad I got to tour a similar facility at the University of Rochester[0] called the laser energetics lab. It’s a similar enormous laser. If I remember, and it’s surely not exactly the same thing, a lot of the issue is around pumping down vacuum spaces. Targets at the lab were suspended from handgrown spider silk (the lab employed a resident spider raiser/silk puller). And they tried to keep the large laser cavity pumped to vacuum constantly because pumping things to ultra low vacuum with things like veto pumps just takes forever. Stuff outgasses and creates militorr of pressure for annoying periods of time. The same issue shows up post maintenance in semiconductor manufacturing. Prep and recovery for maintenance can take 10x the time of the actual maintenance action itself. The facility itself was fascinating. Banks upon banks of capacitors in the basement that apparently sound like a gunshot going off when it’s fired. Giggawatts of power for picoseconds. [0] https://www.lle.rochester.edu/ https://www.lle.rochester.edu/
  - technothrasher 5y ago
    When I was in school at the U of R, I lived with a woman who worked at the LLE. It was fascinating to hear her stories. She showed me a storage building there that had stacks and stacks of Unix workstations piled up collecting dust, because they had had classified info on them and so weren't allowed to be sold or thrown away even though they'd had all their storage removed. That was painful, all I wanted was one. Nobody would notice. She said no. :( But I did manage to get remote access to their Cray-2 by agreeing to do some free sysadmin work for them. U of R has some pretty sketchy nuclear past history though, as the hospital ran some tests in the 1940's of injecting some unwitting patients with plutonium, uranium, and polonium to see what would happen. There's an almost abandoned tunnel (actually, it may well be abandoned at this point) that goes underneath Elmwood Ave between the medical center annex and the hospital proper which has a very old, very locked door labelled "isotope storage chamber". Creepy.
deleted 5y ago
[deleted]
fsflover 5y ago
https://news.ycombinator.com/item?id=28211726 https://news.ycombinator.com/item?id=28211726
web007 5y ago
> The results from the experiment on 8 August indicate an energy output of over one mega-joule, which marks the threshold agreed for the onset of 'ignition' and is six times the previous highest energy achieved. They got 1Mj output from > 500TW input - this is a "major milestone" but only a small step on the path to fusion. NIF is fascinating, and has been promising for the past decade. The idea of kick-starting fusion with lasers sounds awesome, and then more awesome when you realize just how much energy you need for fusion. They're shooting terawatts of laser at a target the size of a hollow grain of rice, and they're not there yet!
- cstross 5y ago
  NIF, remember, is funded by the DoD. It's not a civilian reactor research program: it's a device for testing fusion reactions in the lab now that the Comprehensive Test Ban Treaty means that they're not allowed to test H-bombs out in Nevada. This is not to say that it isn't fascinating and there won't be spin-off findings of use to the development of civil fusion reactors, but actual reactor research (e.g. JET, ITER, Wendelstein-7X) is all about magnetic containment for protracted periods (tens to thousands of seconds). And ITER, running on tritium and deuterium, is supposed to use 50 MW of heating power to create a plasma of 500 MW (thermal) for periods of 400 to 600 seconds. No need for a 500TW peak power input (actually much, much lower when you look at it in terms of megajoules delivered in a few nanoseconds).
  - pxhb 5y ago
    >NIF, remember, is funded by the DoD. It's not a civilian reactor research program: it's a device for testing fusion reactions in the lab now that the Comprehensive Test Ban Treaty means that they're not allowed to test H-bombs out in Nevada. *DOE’. There is a quasi-separation of powers, where DOE ‘owns’ the weapons and the DOD ‘uses’ them. ‘See for example the NNSA.
    - avs733 5y ago
      The DOE is a fascinating organization btw…anyone who is so nonchalant about public oversight and security practices that the DOD gets angry at them has to be fun at parties.
xutopia 5y ago
Can someone explain to me like I am 5 years old what else is needed to make fusion practical?
- msdrigg 5y ago
  Edited to add source Im not an expert but someone pointed out yesterday [0] that this technology is a bit further from practical than implied by the article. This milestone of ‘ignition’ is declared because the laser energy making it into the fusion fuel is less than the energy produced by the fusion fuel. But this is ignoring the fact that there is significant (85% if I remember correctly?) loss of energy as the laser travels through the housing around the fuel. And even more importantly, the laser itself is very inefficient and loses something like 99% of the energy that it pulls from wall power. So even in lab conditions, we need to produce several times more energy to even call it ‘ignition’. And this is not mentioning the many and difficult issues with scaling from lab scar to real-world power plant scale. [0] https://news.ycombinator.com/item?id=28213763 https://news.ycombinator.com/item?id=28213763
- willis936 5y ago
  A carbon tax. The rest is gravy. Also, NIF is not a fusion power research project. Articles that discuss both NIF and fusion power research confuse the public.
- hannob 5y ago
  I can recommend a great article answering that, however unfortunately it's in German [1]. But the gist is that there are two major unsolved challenges. One is finding a material stable enough to let the reactor run for longer times (all experiments like ITER only plan to run the reaction for very short times, which is okay for research, but not useful for real energy). The other is finding a way to produce enough tritium for the reaction. It is expected that ITER alone will consume all the tritium that is available and that is currently only produced in some special kind of nuclear reactor. The idea is that eventually fusion reactors will create this tritium themselve, but noone has figured out how to practically do that. [1] https://taz.de/Energie-durch-Kernfusion/!5707537/ https://taz.de/Energie-durch-Kernfusion/!5707537/
leephillips 5y ago
Discussion yesterday based on a better source: https://news.ycombinator.com/item?id=28211726#28214165 https://news.ycombinator.com/item?id=28211726#28214165
fuoqi 5y ago
The usual reminder that laser fusion research is done not for potential energy production, but for development of thermonuclear weapons: https://news.ycombinator.com/item?id=25210756 https://news.ycombinator.com/item?id=25210756
- Fernicia 5y ago
  Lots of consumer innovations have been the result of military spending!
  - dredmorbius 5y ago
    Word on the street is that "Mr. Fusion" has yet to be slotted for mass-market introduction.
- regnull 5y ago
  Citation needed. And I got one for you. "The mission of the National Ignition Facility ib to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian application, such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project." So, "fusion energy development". It's sorta both. https://inis.iaea.org/collection/NCLCollectionStore/_Public/26/070/26070714.pdf https://inis.iaea.org/collection/NCLCollectionStore/_Public/...
- oh_sigh 5y ago
  That doesn't exactly follow. Knowledge of plasma has more applications than just nukes. Maybe it will help nuke design, and maybe that is even a goal of the project, but that doesn't mean that the knowledge gained is binned in "weapons" category and nothing else. And most research fields are not practical at some point in their lifespans, that doesn't mean it will never be practical, or we won't (hopefully) learn things which make other energy technologies practical.
  - SiempreViernes 5y ago

174 points by dnetesn 5y ago

So ... fusion reactors are only 50 years away now? :)

This is super exciting, but I’m still going to be more excited when it is actual ignition versus close enough ignition :) Does anyone know if they still have to wait for months to open the chamber after experiments to wait for the radioactivity to cool down?

SiempreViernes 5y ago
Why did they have to do that? If there's radioactive gasses to worry about contaminating something important surely they could pump those out, gotta be a good vacuum system for that chamber anyway...
- pstch 5y ago
  In magnetic confinement reactors, the runaway neutrons collide with the reactor's shielding and can make it radioactive by neutron activation. I don't know if it's the same for inertial confinement, but I suppose it could be an explanation.
pxhb 5y ago
> Does anyone know if they still have to wait for months to open the chamber after experiments to wait for the radioactivity to cool down? I don’t think this has ever been the case. Note that I have been involved with experiments on the NIF, but only from the academic side. The NIF typically fires 1-3 time per day, and I believe that this is mostly an optics constraint. We weren’t producing neutrons though, so YMMV.
avs733 5y ago
I can’t speak to NIF but back in undergrad I got to tour a similar facility at the University of Rochester[0] called the laser energetics lab. It’s a similar enormous laser. If I remember, and it’s surely not exactly the same thing, a lot of the issue is around pumping down vacuum spaces. Targets at the lab were suspended from handgrown spider silk (the lab employed a resident spider raiser/silk puller). And they tried to keep the large laser cavity pumped to vacuum constantly because pumping things to ultra low vacuum with things like veto pumps just takes forever. Stuff outgasses and creates militorr of pressure for annoying periods of time. The same issue shows up post maintenance in semiconductor manufacturing. Prep and recovery for maintenance can take 10x the time of the actual maintenance action itself. The facility itself was fascinating. Banks upon banks of capacitors in the basement that apparently sound like a gunshot going off when it’s fired. Giggawatts of power for picoseconds. [0] https://www.lle.rochester.edu/ https://www.lle.rochester.edu/
- technothrasher 5y ago
  When I was in school at the U of R, I lived with a woman who worked at the LLE. It was fascinating to hear her stories. She showed me a storage building there that had stacks and stacks of Unix workstations piled up collecting dust, because they had had classified info on them and so weren't allowed to be sold or thrown away even though they'd had all their storage removed. That was painful, all I wanted was one. Nobody would notice. She said no. :( But I did manage to get remote access to their Cray-2 by agreeing to do some free sysadmin work for them. U of R has some pretty sketchy nuclear past history though, as the hospital ran some tests in the 1940's of injecting some unwitting patients with plutonium, uranium, and polonium to see what would happen. There's an almost abandoned tunnel (actually, it may well be abandoned at this point) that goes underneath Elmwood Ave between the medical center annex and the hospital proper which has a very old, very locked door labelled "isotope storage chamber". Creepy.

deleted 5y ago

[deleted]

fsflover 5y ago

https://news.ycombinator.com/item?id=28211726 https://news.ycombinator.com/item?id=28211726

web007 5y ago

> The results from the experiment on 8 August indicate an energy output of over one mega-joule, which marks the threshold agreed for the onset of 'ignition' and is six times the previous highest energy achieved. They got 1Mj output from > 500TW input - this is a "major milestone" but only a small step on the path to fusion. NIF is fascinating, and has been promising for the past decade. The idea of kick-starting fusion with lasers sounds awesome, and then more awesome when you realize just how much energy you need for fusion. They're shooting terawatts of laser at a target the size of a hollow grain of rice, and they're not there yet!

cstross 5y ago
NIF, remember, is funded by the DoD. It's not a civilian reactor research program: it's a device for testing fusion reactions in the lab now that the Comprehensive Test Ban Treaty means that they're not allowed to test H-bombs out in Nevada. This is not to say that it isn't fascinating and there won't be spin-off findings of use to the development of civil fusion reactors, but actual reactor research (e.g. JET, ITER, Wendelstein-7X) is all about magnetic containment for protracted periods (tens to thousands of seconds). And ITER, running on tritium and deuterium, is supposed to use 50 MW of heating power to create a plasma of 500 MW (thermal) for periods of 400 to 600 seconds. No need for a 500TW peak power input (actually much, much lower when you look at it in terms of megajoules delivered in a few nanoseconds).
- pxhb 5y ago
  >NIF, remember, is funded by the DoD. It's not a civilian reactor research program: it's a device for testing fusion reactions in the lab now that the Comprehensive Test Ban Treaty means that they're not allowed to test H-bombs out in Nevada. *DOE’. There is a quasi-separation of powers, where DOE ‘owns’ the weapons and the DOD ‘uses’ them. ‘See for example the NNSA.
  - avs733 5y ago
    The DOE is a fascinating organization btw…anyone who is so nonchalant about public oversight and security practices that the DOD gets angry at them has to be fun at parties.

xutopia 5y ago

Can someone explain to me like I am 5 years old what else is needed to make fusion practical?

msdrigg 5y ago
Edited to add source Im not an expert but someone pointed out yesterday [0] that this technology is a bit further from practical than implied by the article. This milestone of ‘ignition’ is declared because the laser energy making it into the fusion fuel is less than the energy produced by the fusion fuel. But this is ignoring the fact that there is significant (85% if I remember correctly?) loss of energy as the laser travels through the housing around the fuel. And even more importantly, the laser itself is very inefficient and loses something like 99% of the energy that it pulls from wall power. So even in lab conditions, we need to produce several times more energy to even call it ‘ignition’. And this is not mentioning the many and difficult issues with scaling from lab scar to real-world power plant scale. [0] https://news.ycombinator.com/item?id=28213763 https://news.ycombinator.com/item?id=28213763
willis936 5y ago
A carbon tax. The rest is gravy. Also, NIF is not a fusion power research project. Articles that discuss both NIF and fusion power research confuse the public.
hannob 5y ago
I can recommend a great article answering that, however unfortunately it's in German [1]. But the gist is that there are two major unsolved challenges. One is finding a material stable enough to let the reactor run for longer times (all experiments like ITER only plan to run the reaction for very short times, which is okay for research, but not useful for real energy). The other is finding a way to produce enough tritium for the reaction. It is expected that ITER alone will consume all the tritium that is available and that is currently only produced in some special kind of nuclear reactor. The idea is that eventually fusion reactors will create this tritium themselve, but noone has figured out how to practically do that. [1] https://taz.de/Energie-durch-Kernfusion/!5707537/ https://taz.de/Energie-durch-Kernfusion/!5707537/

leephillips 5y ago

Discussion yesterday based on a better source: https://news.ycombinator.com/item?id=28211726#28214165 https://news.ycombinator.com/item?id=28211726#28214165

fuoqi 5y ago

The usual reminder that laser fusion research is done not for potential energy production, but for development of thermonuclear weapons: https://news.ycombinator.com/item?id=25210756 https://news.ycombinator.com/item?id=25210756

Fernicia 5y ago
Lots of consumer innovations have been the result of military spending!
- dredmorbius 5y ago
  Word on the street is that "Mr. Fusion" has yet to be slotted for mass-market introduction.
regnull 5y ago
Citation needed. And I got one for you. "The mission of the National Ignition Facility ib to achieve ignition and gain in ICF targets in the laboratory. The facility will be used for defense applications such as weapons physics and weapons effect testing, and for civilian application, such as fusion energy development and fundamental studies of matter at high temperatures and densities. This paper reviews the design, schedule and costs associated with the construction project." So, "fusion energy development". It's sorta both. https://inis.iaea.org/collection/NCLCollectionStore/_Public/26/070/26070714.pdf https://inis.iaea.org/collection/NCLCollectionStore/_Public/...
oh_sigh 5y ago
That doesn't exactly follow. Knowledge of plasma has more applications than just nukes. Maybe it will help nuke design, and maybe that is even a goal of the project, but that doesn't mean that the knowledge gained is binned in "weapons" category and nothing else. And most research fields are not practical at some point in their lifespans, that doesn't mean it will never be practical, or we won't (hopefully) learn things which make other energy technologies practical.
- SiempreViernes 5y ago