Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

theconversation.com

Post reply on HN
Print view View original

61–70 of 289 posts

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#61

Post by moffkalast »

albertopv wrote: post #57
moffkalast wrote: post #53

Earlier quoted context omitted.

I've also been quite surprised watching that one, it's completely novel approach to fusion and it may be the best way to mass adoption. If they can make it work that is. What most surprised me about NIF's ignition announcement was that this was even news. I'd assumed for years that most if not all tokamaks and stellerators could already achieve at least some brief fusion, just not to a useful degree. Turns out they'r…

I'm very skeptical about those great announcements, even more when there's an announcement of the announcement. 300MJ in, 3MJ out, I wouldn't call it a breakthrough, maybe a milestone, nothing more.

I mean yeah it doesn't really change much in terms of usability, but it is the point from where onwards you can actually say you're doing fusion and not just heating stuff to high temps.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#62

Post by hoseja »

mirekrusin wrote: post #24
garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

Ignition doesn't have to be net positive. It just needs to enter into state of self sustained reaction that is net positive. Ignition itself can be horribly inefficient. Nobody is designing fussion where ignition's output is directly used for the whole system to reignite again. It would be equivalent to moving hand with match that fires a match, where energy from ignition is used to trigger another hand to move anoth…

This isn't a system that can ever do a sustained reaction.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#63

Post by rob74 »

Systemic33 wrote: post #50
rob74 wrote: post #43

Still unconvinced why this is such a major breakthrough - it may be the first net-positive controlled fusion, but the distinction between controlled and uncontrolled fusion is a bit academic in this case. In uncontrolled fusion ( https://en.wikipedia.org/wiki/Thermonuclear_weapon ), you are using a nuclear fission primary stage to generate enough energy to start the fusion reaction in the secondary stage. In the NIF,…

With regards to NIF being a military facility, I'd very much think that energy production (cheap, safe, limitless?) is very much a military needs as much as a civilian need. Even if said energy goes further to power laser weapons or other exotic power hungry systems; energy is energy, and something has to produce it.

Depends - if someday they manage to make the fusion generators compact enough (think of the coffee-machine-sized "Mr. Fusion" that Dr. Brown brought back from 2015 in Back to the Future where you could throw in any kind of junk and it would use it to provide energy, or even the shipping container-sized units that Lockheed Martin is envisaging), it might be interesting for military purposes. But it's very optimistic to believe that the NIF will seriously work on sustained fusion and extracting the generated energy in a usable way - after all they are called National Ignition Facility, so now they achieved that, mission accomplished. They can now run further ignition experiments with various pellets, laser configurations etc. and study the results, but they will probably say that a new facility (and more money) is needed for further studying sustained fusion.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#64

Post by TheOtherHobbes »

skelpmargyar wrote: post #17
garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

It's better to focus on standardised production lines for small fission reactors currently if your goal is to produce energy for the power grid right now, but that's not what cutting-edge research or science is about. Whoever launched the first firework probably didn't see how people could walk on the moon either. Science is rarely a linear path. It's also rarely "I have this problem so I solved it this way." That's…

That's because this breakthrough is being sold - from a dull business and product oriented perspective - as an incredible etc etc which makes a new kind of product more likely.

No one is shitting on the research itself. But the PR around this story has carpet bombed sci-comm as a potential practical energy source. Not as basic research.

So it's perfectly reasonable to ask if there's a there from a commercial POV. And to note out that currently there really isn't.

If they really had announced a viable commercial product everyone here would be cheering.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#65

Post by sudhirj »

It’s practical proof that in a single pulse we can get more energy out than we put in. We do spend a shit ton of energy setting up the pulse, and we haven’t figure out how to get that energy out and make electrons move, but it’s been proven possible.

The “breakthrough” is the proof that it’s possible. Everything else is now optimisation and engineering, and needs mostly time, sweat and money.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#67

Post by DecoPerson »

noobermin wrote: post #54
oblio wrote: post #51

Earlier quoted context omitted.

The internet was a military need from what I remember. The military said something like: "Telephone routing is point to point and inflexible, if the enemy cuts out 1-2 lines of communication, an entire section is completely cut off. We need something better." That something better turned out to be packed switching where you just throw stuff along a network and the network ensures that the packet reaches the destinati…

That said while the intent the current internet is pretty centralized at least in some senses.

But it’s software defined, so it’s much quicker to work around failures of those centralised points.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#68

Post by maegul »

sudhirj wrote: post #65

It’s practical proof that in a single pulse we can get more energy out than we put in. We do spend a shit ton of energy setting up the pulse, and we haven’t figure out how to get that energy out and make electrons move, but it’s been proven possible. The “breakthrough” is the proof that it’s possible. Everything else is now optimisation and engineering, and needs mostly time, sweat and money.

Yea, and I wonder how much our need, at a cultural level, for progress will factor into this. If we feel like we need to progress and can't go "backward" with our energy technology, there may just be an irrational impetus to make it happen.

Solar and wind etc may just feel too "primitive" and nuclear too old and toxic and Chernobyl. Fusion though, once there's enough buy in and enough of a sense of it being doable, would fit our expectation of technological progress.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#69

Post by Cthulhu_ »

albertopv wrote: post #57
moffkalast wrote: post #53

Earlier quoted context omitted.

I've also been quite surprised watching that one, it's completely novel approach to fusion and it may be the best way to mass adoption. If they can make it work that is. What most surprised me about NIF's ignition announcement was that this was even news. I'd assumed for years that most if not all tokamaks and stellerators could already achieve at least some brief fusion, just not to a useful degree. Turns out they'r…

I'm very skeptical about those great announcements, even more when there's an announcement of the announcement. 300MJ in, 3MJ out, I wouldn't call it a breakthrough, maybe a milestone, nothing more.

And yet, they need to keep making announcements, else their funding will be cut.

They knew all along that fusion energy would take decades to develop, and every year they need billions in funding to keep pushing for advancements.

They can't just go radio silent until they're like "we've done it", they need to regularly publish papers and make big media announcements etc.

Come to think of it, the LHC has been silent for a good while. Edit: It had a 3 year hiatus, started up again April this year.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#70

Post by sandworm101 »

nottorp wrote: post #66

No one's commenting on the self sustaining part. Would it have kept going without external energy input if they had more fuel? I don't think the 1% system wide would matter if it just went on after the first few seconds.

No. This was inertial confinement fusion, like in a bomb. The reaction could not have continued under any circumstance. The only hope would be to run this test repeatedly, like ten times a second, and somehow pull put power. But this machine has no hope of even attempting that.
Post reply on HN