Skunk Works Reveals Compact Fusion Reactor Details • Hacker News Board

Re: Skunk Works Reveals Compact Fusion Reactor Details

#361

Post by scottlocklin » Fri, Oct 17, 2014, 5:00 AM UTC

Gravityloss wrote: post #359

scottlocklin wrote: post #302

Earlier quoted context omitted.

"Top physicists?" Fusion is an engineering problem. The thing to check here is what plasma temperature/densities they have achieved with their new confinement scheme. They've basically said the results are preliminary, and some of the results are from simulation (which should not be trusted; aka look at how well the NIF simulations worked). This is not particularly interesting. Shielding was mentioned, though not eno…

I don't think it's "just engineering". Plasma physics is quite complicated.

Fair enough. There aren't many household names in physics working in that field. The closest ones to that description have their own fusion startups, like d-wave.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#362

Post by kbart » Fri, Oct 17, 2014, 12:22 PM UTC

rayiner wrote: post #289

petercoolz wrote: post #287

Earlier quoted context omitted.

To be clear, the price of energy goes negative because of government subsidies. For example, a wind plant with a $30/MWH subsidy can afford to run at a price of -$30. Similarly, if you're in California and you ever wondered why your electricity bill is 2x that of any other state, it is because you are the ones footing the bill for those subsidies. Without subsidies, wind and solar are far more inefficient at a $/MWH…

Being able to externalize pollution is a subsidy. Accounting for externalized costs, coal is about parity with wind in terms of cost, though gas is ahead of both.

Yes, there was an article about that few days ago: http://www.theguardian.com/environment/2014/oct/13/wind-powe...

Re: Skunk Works Reveals Compact Fusion Reactor Details

#363

Post by regularfry » Fri, Oct 17, 2014, 12:55 PM UTC

drjesusphd wrote: post #319

regularfry wrote: post #112

Earlier quoted context omitted.

Take a look at the footprint of ITER. It surprised me how massive the thing is planned to be. That's the competition.

> Take a look,at the footprint of ITER Or any other power plant for that matter. "If it sounds too good to be true..."

The area energy density of ITER is particularly low. The whole plant is only designed to produce 500MW, on a concrete platform 1000mx400m.

Compare that to this: https://www.google.co.uk/maps/place/Barking+Power+Station,+B... google.co.uk

That's a 20 year old 1GW combined cycle gas plant, in a building roughly 50mx150m. Anything they can do to bring fusion plants smaller than ITER is going to help.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#364

Post by marktangotango » Fri, Oct 17, 2014, 3:47 PM UTC

nether wrote: post #162

sounds wrote: post #132

Earlier quoted context omitted.

This is a very good point. Extraordinary claims... If you haven't hung around talk-polywell.org before, you might want to. It's focused on the polywell but they seem to at least try to fairly evaluate all contenders. New confinement techniques (NIF, this article, Helion, Polywell) are actually making real progress. So it's becoming less likely that an announcement like this is 100% vapor. Put another way, we're getti…

The AviationWeek article even mentions that the LMSW team drew from Polywell: > "We also have a recirculation that is very similar to a Polywell concept," he adds, referring to another promising avenue of fusion power research. A Polywell fusion reactor uses electromagnets to generate a magnetic field that traps electrons, creating a negative voltage, which then attract positive ions. The resulting acceleration of th…

It doesn't talk about how recirculation is used. I was thinking maybe it has something to do with sealing the cylinder end caps, to keeping plasma loss to near zero?

Re: Skunk Works Reveals Compact Fusion Reactor Details

#365

Post by tonyplee » Fri, Oct 17, 2014, 4:55 PM UTC

tjradcliffe wrote: post #325

tonyplee wrote: post #185

Earlier quoted context omitted.

How much dangerous are the neutrons from such device? Similar to radiation, worst? Time sell any oil company stocks, mutual fund holding?

There are a variety of more-or-less sort-of correct answers below, but I'll throw in my two cents regardless. I am a nuclear physicist who spent a lot of time worrying about neutrons, which are a major source of backgrounds in neutrino detectors. Two points made reply to you are correct: neutrons are radiation, but not electromagnetic radiation; and neutrons can make other things radioactive. Some thing other people…

The neutrons from these reactor makes surrounding matters radioactive? Doesn't sound too good. The fission reactor is not really as clean as it sound at first?

Putting a mice next to this system can make it a "carbon-14" mice? Can it glow in the dark? :-)

Re: Skunk Works Reveals Compact Fusion Reactor Details

#366

Post by tonyplee » Fri, Oct 17, 2014, 5:02 PM UTC

FiatLuxDave wrote: post #233

hendler wrote: post #205

Earlier quoted context omitted.

http://www.thomasnet.com/products/neutron-shielding-74851395...

The majority of those suppliers provide boron-impregnated plastic, which is fine for e.g. shielding spallation neutrons from a medical linac head. Reactor shielding is orders of magnitude higher, so material damage is a real concern. Not to say that people can't or don't use that material, but it is not the most cost effective stuff. Frankly, the best neutron shielding in the world, on a per-cost basis, is water with…

According to "neutrons make other things radioactive", does it make your water with borax radioactive too?

Re: Skunk Works Reveals Compact Fusion Reactor Details

#367

Post by tonyplee » Fri, Oct 17, 2014, 5:04 PM UTC

graycat wrote: post #252

adventured wrote: post #187

Earlier quoted context omitted.

Time to buy airline stocks. If you can put a miniature fusion power plant on an 747 equivalent, airline profit margins will skyrocket. Actually even if you believed there's a chance this Lockheed concept can work, the time to buy airline stocks would be on the back end of this dead bull market that's about to fall off a cliff. And then there's the 20 year wait before it's finally deployed to a commercial airplane.

A fusion powered 747 might be the result, but maybe not! Instead, let's see: With the CFR, we've got dirt cheap electric power. Okay, then we can also use that power to make dirt cheap, very clean water. Then, yup, we can take that water, more of that power, and coal and make jet fuel. And maybe that is what the 747s would continue to use! Maybe!

According to "neutrons make other things radioactive", anything that carry by that fission 747 "might" be radioactive after a flight.

True?

Re: Skunk Works Reveals Compact Fusion Reactor Details

#368

Post by huxley » Fri, Oct 17, 2014, 6:27 PM UTC

scottlocklin wrote: post #361

Gravityloss wrote: post #359

Earlier quoted context omitted.

I don't think it's "just engineering". Plasma physics is quite complicated.

Fair enough. There aren't many household names in physics working in that field. The closest ones to that description have their own fusion startups, like d-wave.

I thought D-Wave was a quantum computing company?

Re: Skunk Works Reveals Compact Fusion Reactor Details

#369

Post by graycat » Fri, Oct 17, 2014, 11:10 PM UTC

tonyplee wrote: post #367

graycat wrote: post #252

Earlier quoted context omitted.

A fusion powered 747 might be the result, but maybe not! Instead, let's see: With the CFR, we've got dirt cheap electric power. Okay, then we can also use that power to make dirt cheap, very clean water. Then, yup, we can take that water, more of that power, and coal and make jet fuel. And maybe that is what the 747s would continue to use! Maybe!

According to "neutrons make other things radioactive", anything that carry by that fission 747 "might" be radioactive after a flight. True?

From what I've read at just the level of Wikipedia, I'd guess yes. But nuclear physics just is not my field.

I wanted my Ph.D. in mathematical physics, but all the physics courses I could find did the math in very sloppy ways, and my hope for any research progress in physics wanted to do the math with full care. I did get much of that math, but by then I was occupied with my money making work and didn't get back to physics. I'd like to, maybe, someday! Then maybe I'll be able to give you a solid answer.

For now, some of the discussions claim that a lot of neutrons will make a metal brittle but don't go the next step and explain just why. Before I'd say anything about what neutrons do, if only as a check on the level of understanding, I'd want to know why.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#370

Post by maxerickson » Fri, Oct 17, 2014, 11:18 PM UTC

graycat wrote: post #369

tonyplee wrote: post #367

Earlier quoted context omitted.

According to "neutrons make other things radioactive", anything that carry by that fission 747 "might" be radioactive after a flight. True?

From what I've read at just the level of Wikipedia, I'd guess yes. But nuclear physics just is not my field. I wanted my Ph.D. in mathematical physics, but all the physics courses I could find did the math in very sloppy ways, and my hope for any research progress in physics wanted to do the math with full care. I did get much of that math, but by then I was occupied with my money making work and didn't get back to p…

This seems to explain much of it:

http://en.wikipedia.org/wiki/Wigner_effect

Whatever production process partially relies on arranging the crystal structure of the metal to arrive at desirable properties, the neutrons disrupt it.