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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

#531

Post by asdff »

zizee wrote: post #511
p_j_w wrote: post #373

Earlier quoted context omitted.

>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 abo…

The boring company was literally an elaborate scheme on the other hand. Fool me once, shame on you. Fool me, you can't get fooled again.

Re: US Department of Energy: Fusion Ignition Achieved

#532

Post by sterlind »

LarryMullins wrote: post #430
jocaal wrote: post #256

Earlier quoted context omitted.

I don't think a pure fusion bomb will have any form of advantage compared to the current hydro-bombs. They wouldn't produce more energy, but will need more gear to reach ignition.

A pure fusion bomb would produce less (not zero) fallout. Neutron activation would still produce some fallout, but you wouldn't have the fission byproducts like caesium-137, iodine-129 or strontium-90. This is probably a bad thing; politicians might decide the bombs are clean enough to use.

even without actual radioactivity, pure fusion bombs would still be politically radioactive. look at the fallout (so to speak!) from the Hafnium controversy. they nixed all the research and stopped looking, after realizing that nuclear isomers would do little for energy storage (due to emitting energy as gamma radiation) but lots for bypassing restrictions on fissile materials.

Re: US Department of Energy: Fusion Ignition Achieved

#533

Post by hnuser123456 »

marcyb5st wrote: post #481
jmartrican wrote: post #443

Earlier quoted context omitted.

So that means that for life to form, we probably need a star to die so that the heavier atoms used in complicated life forming chemical reactions (correct me if i am wrong here as what I'm about to say depends on it), hence it could be the case that if the universe is 13.5 billion years old, then we humans are appearing in the universe at the earliest possible time. 13.5 billion years seems like the time required to…

Not necessarily. First generation stars were, theoretically, enormous both due to low metallicity of the collapsed medium and a higher average concentration of said medium. These stars lifespans were extremely short, shorter that blue giants we see today. So novas due to the death of these stars happened fairly early in the lifespan of the universe (talking about few million years after the big bang). Therefore, life…

Basic life (single-celled?) requiring the elements above lead might have a chance at that time, but complex life like us wouldn't do so well if there were still supernovas going off left and right. There's a theory with decent evidence that at least one of the mass extinctions was caused by a supernova: https://www.space.com/supernova-caused-earth-mass-extinction...

That being said, I wasn't aware of how LIGO changed the understanding of how heavier elements are usually formed, guessing it changed the expected neutron star prevalence? Do you have any additional reading on that?

Re: US Department of Energy: Fusion Ignition Achieved

#534

Post by davidklemke »

BadBadJellyBean wrote: post #506
twic wrote: post #429

Earlier quoted context omitted.

Take spullara's numbers: 2.01410177811 u = 3.34449439340696e-24 g deuterium 3.01604928 u = 5.008267217094e-24 g tritium 17.6 MeV = 7.832863e-19 kWh energy Divide through, and you will see that you need 4.27 ug/kWh of deuterium, and 6.39 ug/kWh of tritium. A random source [1] says that New York will use 50.6 TWh per year by 2027. That would require ~216 kg/yr of deuterium and ~323/yr kg of tritium. This is all assumin…

I wonder if that is much or not. I have no idea how hard this is to produce. Do you have an idea about that?

The concentration of deuterium in the ocean is about 150-160 parts per million and with 1233.91 quintillion liters covering the earth we have approximately 8.2260667e+12kg worth of it to extract, so we've got a bit to work through!

Tritium however is far more rare with only trace amounts of it being available within nature and barely more than a kg produced per year. Producing the 100s of kgs required per year still seems to be an unsolved problem, although my quick searching shows there's a couple viable solutions for it.

Re: US Department of Energy: Fusion Ignition Achieved

#535

Post by mlyle »

dharmab wrote: post #126
thehappypm wrote: post #45

Earlier quoted context omitted.

It’s potentially just a much better version of fission. Fusion won’t cause a runaway reaction — in fact it’s brutally difficult to get it to react at all, hence why this is an achievement. It also doesn’t use materials that can be used for a bomb, again unlike fission. As a result it has the potential to be cheaper to implement, cheaper to fuel, with no meltdown risk.

Isn't tritium used in fusion and a potential weapons material?

It's not controlled. It does help boost some fission weapons. But it's not the hard part or critical piece of producing a nuclear weapon, and you can get by without it.

To illustrate how little it's controlled-- I have a little bit on my keychain as an alpha source with a phosphor so my keyring always glows.

Re: US Department of Energy: Fusion Ignition Achieved

#536

Post by nerpderp82 »

ClumsyPilot wrote: post #505
azinman2 wrote: post #204

Earlier quoted context omitted.

Is the bottleneck for fusion money though?

There are like 20 designs of various fusion reactors on the drawing board that need to be built and tested. Scientists also don't work for free. They arent mushrooms that grow by themselves

One of the things that I think I noticed from the press conference, is that funding is going to be the bare minimum to meet some goal for a design they select.

This seems like a gross mistake.

If we are going to avert a climate catastrophe we will need TW of power to "unburn" the carbon we put into the environment (ocean and atmosphere). Instead of barely hitting this target, we should over deliver since we are running out of wall-clock time.

Every project that meets a bar for feasibility, organizational/operational capabilities (if they dont have it, either fix it, or transfer design to capable team) should be given funding (50-100M). We should be dropping BILLIONS on this, if we can drop 50B+ on semiconductors we can do the same for fusion.

Re: US Department of Energy: Fusion Ignition Achieved

#537

Post by mlyle »

davidklemke wrote: post #534
BadBadJellyBean wrote: post #506

Earlier quoted context omitted.

I wonder if that is much or not. I have no idea how hard this is to produce. Do you have an idea about that?

The concentration of deuterium in the ocean is about 150-160 parts per million and with 1233.91 quintillion liters covering the earth we have approximately 8.2260667e+12kg worth of it to extract, so we've got a bit to work through! Tritium however is far more rare with only trace amounts of it being available within nature and barely more than a kg produced per year. Producing the 100s of kgs required per year still…

The solution is that fusion power plants can breed tritium and become net producers of it...

Though in practice enough will be lost that probably they'll still be somewhat net consumers-- just not nearly to the extent predicted by a simple thermodynamic model.

Still, even if fusion becomes a net producer of tritium, the whole tritium-is-hard-to-get problem will likely be a constraint that we'll be fighting as we ramp up use of fusion power in the future.

Re: US Department of Energy: Fusion Ignition Achieved

#539

Post by LarryMullins »

krainboltgreene wrote: post #523
zaroth wrote: post #362

Earlier quoted context omitted.

I can't agree that funding is "largely the reason" why NASA takes so long to do anything. I doubt funding is a top 3 reason. NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics. NASA will get back to the moon using easily an order of magnitude more funding than it should have taken, with a launch system that costs an…

> I can't agree that funding is "largely the reason" > NASA just isn't about high-risk / high-reward "moonshots" anymore. The overarching political environment doesn't allow it, never mind the office politics. Why doesn't the political environment allow for it. What could happen. What could regulatory bodies do to NASA for taking a risk and failing. What sort of constricting change could political bodies do in such a…

> Why doesn't the political environment allow for it. What could happen.

Three astronauts were incinerated alive. That was when they started to take safety more seriously. Subsequent accidents have only reinforced this.

Re: US Department of Energy: Fusion Ignition Achieved

#540

Post by heavyset_go »

jmartrican wrote: post #443
eklitzke wrote: post #262

Earlier quoted context omitted.

Tangentially related, but I think this is an interesting fact, all the atoms in our universe/galaxy/solar system with a mass up to that of iron are formed in the core of stars in stellar fusion. Hydrogen fuses into helium, and as a star nears the end of its lifetime you get heavier elements like lithium, carbon, and so on. Under normal stellar fusion no elements heavier than iron will be produced, and iron is only el…

So that means that for life to form, we probably need a star to die so that the heavier atoms used in complicated life forming chemical reactions (correct me if i am wrong here as what I'm about to say depends on it), hence it could be the case that if the universe is 13.5 billion years old, then we humans are appearing in the universe at the earliest possible time. 13.5 billion years seems like the time required to…

> 13.5 billion years seems like the time required to create a star, have the star die and blow up, have all that material settle and create a new star, then the planets are formed, than enough time on one of those planets needs to pass for life to form, then complicated life.

Maybe for a main sequence star, but there other processes that involve nucleosynthesis.

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