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US Department of Energy: Fusion Ignition Achieved

energy.gov

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Re: US Department of Energy: Fusion Ignition Achieved

#511

Post by zizee »

p_j_w wrote: post #373
adventured wrote: post #292

Earlier quoted context omitted.

Given it's Musk and his stated primary life goal, the most ridiculous aspect of the Twitter debacle for him, is: not only of course did he overpay for Twitter by at least 2x; not only is his net worth going to contract as Tesla's stock compresses (such that the poor Twitter decision is going to be that much more painful in relation to his overall wealth); but the $40x billion could have probably paid for getting Star…

>the $40x billion could have probably paid for getting Starship to Mars. Maybe he doesn't actually believe in Starship.

Are you suggesting it's all an elaborate scheme?

I know it is popular/easy to hate on the man right now, but this is a really strange take.

Given that Musk has been talking about mars since at least 2001, many years before he had the resources he has now, and almost went bankrupt funding spacex's first orbital rocket, it's hard to believe he's pretending.

People seem happy to believe all negative things they hear about him, but discount anything that doesn't gel with this negative image. It's like how the same people who put all missteps of Tesla/SpaceX at Elons feet, will also discount any of the successes and say he has nothing to do with them.

Re: US Department of Energy: Fusion Ignition Achieved

#512

Post by XorNot »

ars wrote: post #466
yonaguska wrote: post #445

Earlier quoted context omitted.

Tritium is very popular on gun sights as well- as it's a glow in the dark sight that doesn't need to be charged. I'm now questioning the practice of appendix carrying with tritium sights.

Tritium decays by beta-decay (an electron). The electron can not travel very far in air (1/4 inch), and is stopped by even the thinnest piece of metal. It's even stopped by the dead outer layer of your skin. i.e. it's completely harmless unless you eat it.

Not quite: beta decay will penetrate the skin enough to damage living tissue - beta burns are what caused the fatalities of the Chernobyl first responder fire fighters.

They spent a few hours covered in dust on their coats, and did a bunch of subsurface skin damage which manifested as third degree burns. Sepsis, not radiation poisoning, generally killed them.

Re: US Department of Energy: Fusion Ignition Achieved

#513

Post by randomsearch »

This is a really hard question to answer, but do you think in peacetime 1930s if you’d asked someone how long it would take to build the bomb, they’d say “we’re only a few decades away with proper funding”?

The pay off achieved by accelerating fusion development seems to justify almost any amount of spending. Is it worth going for it?

The most important subquestion for me: is there a sufficiently brilliant living scientist who has the technical ability, managerial skills, and integrity to be trusted to deliver? I wonder if this is the reason we haven’t already done it.

Re: US Department of Energy: Fusion Ignition Achieved

#514

Post by nine_k »

IgorPartola wrote: post #498
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

I keep getting lost in the numbers here. What was the net gain/loss for the entire system? Without the “lasers are 1% efficient at 20% energy loss with 40% energy transfer loss” and all that.

AFAICT: There's a large net gain compared to the energy emitted by the lasers. There is still a considerable loss compared to the energy consumed by the lasers.

While at it: I don't think the NIF approach will ever be applicable to commercial power generation on Earth. But I hope it will be one day applicable to a fusion-based rocket engine.

Re: US Department of Energy: Fusion Ignition Achieved

#515

Post by emmelaich »

bmmayer1 wrote: post #103
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

This is a stupid question but I don't know anything about fusion: How is it possible for X energy to create X+Y energy in output? Doesn't that violate some fundamental law of physics?

The answers you got are excellent but a short response might just say you don't start with just X energy.

In a sense it's no more mysterious (conservation of energy-wise) than adding the energy of a spark results in the energy of the wood fire.

i.e. energy is transformed, not created as you quite accurately write.

Re: US Department of Energy: Fusion Ignition Achieved

#516

Post by ClumsyPilot »

pfdietz wrote: post #71
jkelleyrtp wrote: post #33

> LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE) Yesterday, everyone was complaining about the 2.2:2.0 ratio, but now we're working with 3.15:2.05. With modern lasers, that'd be a total Q of 0.375 assuming 100% ef…

The Q needs to be something like 500 to 1000, not because of energy breakeven, but to produce enough energy that the shot is financially positive. The amount of fusion energy produced in this shot is worth a penny or two. (And even then, it's dubious a laser fusion scheme will be competitive with other energy sources.)

Q is irrelevant, you need throughput. If your Q is one million, but you are processing one tiny capsule per second, you are producing too little money to pay for the facility.

If you can process a tanker worth of hydrogen per second, Q can be just above break even and you will still make money.

Re: US Department of Energy: Fusion Ignition Achieved

#517

Post by daxfohl »

chrisco255 wrote: post #502
daxfohl wrote: post #484

My pessimistic self feels like the short-term effect is that it sets a deadline by which oil companies know they have to extract and sell all the existing oil on the planet, and a doubling down on increased emissions now because fusion will solve it eventually.

There are hundreds of years worth of oil deposits (possibly more) even at current usage rates. "Selling all the oil" isn't in the realm of possibility.

Still, as much as possible before the party is over.

Re: US Department of Energy: Fusion Ignition Achieved

#519

Post by jackmott »

nine_k wrote: post #514
IgorPartola wrote: post #498

Earlier quoted context omitted.

I keep getting lost in the numbers here. What was the net gain/loss for the entire system? Without the “lasers are 1% efficient at 20% energy loss with 40% energy transfer loss” and all that.

AFAICT: There's a large net gain compared to the energy emitted by the lasers. There is still a considerable loss compared to the energy consumed by the lasers. While at it: I don't think the NIF approach will ever be applicable to commercial power generation on Earth. But I hope it will be one day applicable to a fusion-based rocket engine.

No post body was provided.

Re: US Department of Energy: Fusion Ignition Achieved

#520

Post by davedx »

TeeMassive wrote: post #473
davedx wrote: post #393

Earlier quoted context omitted.

We've had thermonuclear weapons (h-bombs) for a long time already. Harnessing the energy in a controlled and sustainable fashion is what's hard.

H-bombs use the hydrogen to produce more neutrons which boosts the fission process. It still is a fission bomb.

Nope...

"thermonuclear bomb, also called hydrogen bomb, or H-bomb, weapon whose enormous explosive power results from an uncontrolled self-sustaining chain reaction in which isotopes of hydrogen combine under extremely high temperatures to form helium in a process known as nuclear fusion."

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