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

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

#11

Post by Jensson »

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.

Engineered lasers are over 10x more efficient at emitting light than what they got, and it is very possible they could improve the fusion ignition process to generate more per laser needed, so I wouldn't rule this out yet.

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

#12

Post by tmikaeld »

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.

For one, it's theoretically impossible to make lasers 102 times more efficient, especially if you consider the current industrial efficiency of up to 20% (30% under special conditions).

For example, the maximum efficiency of a laser is limited by the quantum efficiency of the laser material, which is the ratio of the number of photons emitted by the laser to the number of charge carriers (electrons and holes) injected into the laser material. The quantum efficiency of most laser materials is less than 100%, which means that there is a limit to the efficiency that can be achieved.

In addition, the efficiency of a laser is also limited by the thermodynamic laws of thermodynamics, which state that it is not possible to convert heat or any other form of energy into work with 100% efficiency. This means that there is always some amount of waste heat generated when a laser is operated, which limits its efficiency.

In other words, fusion is unlikely to be using lasers for the ignitions.

UPDATE: People here seem to believe in self-sustained fusion, but this has never been tried or proven to be possible - no one know how much energy is needed for repeated ignition.

The current plan is to re-ignite new pellets fed into the containment.

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

#13

Post by dncornholio »

People don't believe the hype anymore so the solution is to not make 1 news article, but dozens of news articles. Maybe the people will start believing again!

I've seen as many articles that says it's not as major of a breakthrough. It's marginal at best.

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

#14

Post by fallingknife »

a3w wrote: post #2

Fusion bombs soon with a laser primer instead of fission for heat generation? Not yet I guess. Clean power? Perhaps never.

Actually, the tech that you are hinting at would guarantee clean fusion power. If you could generate clean fusion explosions, detonate underground and use the heat to generate power. Nuclear bombs are currently the only net energy positive fusion devices we have.

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

#17

Post by skelpmargyar »

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 more engineering than science. It's really disappointing to me to see people, for lack of a better term, just shit on this accomplishment on HN when it's some seriously amazing stuff. It seems like a lot of people here don't understand science, they only understand engineering and then think about engineering mostly from a dull business and product oriented perspective.

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

#18

Post by arethuza »

fallingknife wrote: post #14
a3w wrote: post #2

Fusion bombs soon with a laser primer instead of fission for heat generation? Not yet I guess. Clean power? Perhaps never.

Actually, the tech that you are hinting at would guarantee clean fusion power. If you could generate clean fusion explosions, detonate underground and use the heat to generate power. Nuclear bombs are currently the only net energy positive fusion devices we have.

Most bomb designs are fission-fusion-fission - most of the energy comes from the fission of the casing of the secondary by neutrons from the fusion process in the secondary.

Edit: Mind you - there were tests like the huge Tsar Bomba that de-rated at 100+ Mt design to 50Mt be leaving out the final fission stage - the output being mostly from fusion.

https://en.wikipedia.org/wiki/Tsar_Bomba

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

#19

Post by throw827474737 »

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.

Depends on what you want to achieve, but with that attitude humanity would not have gotten anywhere.

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

#20

Post by noobermin »

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.

People can do multiple things at once...or rather, different people can do different things simultaneously, there is no need to "better focus on" x over y.
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