Fusion energy breakthrough by US scientists boosts clean power hopes

Interesting link.

If you mean the NIF thing, it made more energy out than laser energy in, but is wildly unlikely to ever be a practical power source. Wall-plug efficiency is still minute, and neutrons are hard to convert to electricity.

We did the master timing system and two generations of beam modulators. We recently redesigned the modulators because ultra-precise low-noise optical waveforms are needed to stably compress a fuel pellet to fusion density using 192 laser beams, sort of like squeezing a balloon (or a plutonium sphere.) Tokamaks have a similar compression instability problem.

I think NIF got over unity once in a single freak shot last year that was unexplained. Maybe with better theory (and better gear!) they can do it repeatedly.

A step in the right direction.

Maybe I will see a sustained reaction sometime in my life.

That's somewhere around 20 years, maybe.

boB

On a sunny day (Tue, 13 Dec 2022 07:48:52 -0800) it happened John Larkin snipped-for-privacy@highlandSNIPMEtechnology.com wrote in snipped-for-privacy@4ax.com:

Sorry wrong link, this was the intended one:

Was also on CNN today, so must be real ;-(

If its real then its cool!

confinement fusion is noting new, look up 'Farnsworth fusor'

kids have done it. but break-even sure is!

Only another factor of about 1k to go. Don't hold your breath.

What's the efficiency of their lasers, really? And what about the efficiency of the whole facility?

Jeroen Belleman

It's air conditioned to +- millikelvins, in Livermore CA.

Possibly the world's biggest clean room.

This is not a breakthrough. The energy required to produce the laser pulses is significant but it is ignored. See

NIF has no way to turn the energy into electricity. This will incur additional losses, so the overall net energy will be much less than unity. Sabine Hossenfelder has written about this problem in The ideal solution is a Thorium Molten Salt Reactor. This will provide clean, walk-away safe energy for many thousands of years.

And the usual highly radioactive fission residues that will have to be kept safely isolated for hundreds of thousands of year. What is actually fissioned is U-233. The difference from regular nuclear reactors is that it is formed in situ by neutron capture from Th-232. There's no U-238 around so you don't get any pjutonium

I wouldn't get too excited about fusion yet: the experiment produced enough energy to power a Tesla for about one mile (305 WHr). And if you compare the cost to produce that energy vs what it costs off of the grid you would be massively disappointed. The main point was that they were able to have a net power output, a first for fusion research.

BTW, what is "pjutonium?"

Not exactly. They saw a net power output, but they weren't able to do it again.

didn't quite get to break even, but could do it repeatedly.

scales up the machine to a point where it should be able to do it reliably. It won't generate any power, but will give the kind of data that you could use to design an actual generating station.

A typo. Somebody with even slightly more sense that Sewage Sweeper wouldn't have needed to ask.

Is that even possible, conditioning air to millikelvin stability? I don't believe it.

Jeroen Belleman

While I tend to agree that thorium reactors merit more attention, I don't think that they are as ideal as you want us to believe. There will still be radioactive waste and should one ever have an accident causing a core dump, that probably means the end of that reactor. A very expensive failure, even without radioactive leaks.

The real problem is that the people who have to decide on the energy production strategy are very susceptible to public opinion, and the general public understands bugger all about energy.

Jeroen Belleman

For a small enough volume of air it is certainly possible. For a space as big as the whole NIF it would be tricky - but they might stabilise important individual air volumes that well, with separate air-conditioners.

John Larkin has clearly misunderstood something, and he's no more likely to tell how he got it wrong than Flyguy would be.

They might need to stabilise the air in individual light paths to that degree if the light paths were routed through air, but it would be easier to evacuate them.

A core dump merely means heating the salt back to temperature and pumping it back into the reactor. How do you think they got it there in the first place.

The radioactive waste is a very small fraction of the initial load, and it decays very quickly - in about 300 years instead of the 30,000 years in conventional pressurized water reactors.

Many of the materials in the thorium reactor waste are very valuable. Since the process is molten, they can be separated fairly easily. Here is one article that describes it:

LFTR Chemical Processing & Power Conversion - Kirk Sorensen

Total unmitigated nonsense. Fissioning U-233 produced much the same mix of fragments as fissioning U-235 or Pu-239

some of them are very radioactive with short half lives, and some of them have longer half lives. As you can see from the wikipedia page there's not a lot of difference between any of the three sets of fission products.

Your claim of a maximum half life of 300 years for U-233 is decidedly implausible.

Many of them are very radioactive

If working with an intensely radioactive starting material could ever be described as "easy".

<snipped the rest - watching somebody evade the obvious on youtube would be very tedious.>

In tabletop-sized volumes, yes. You put a box in a box, and stir the space between with a fan. Over an entire building? Ambitious. ;)

Cheers

Phil Hobbs

Our gear, in the Master Oscillator Room, is spec'd to work over a

+-0.3c range, but MOR isn't as stable as the laser lines. We're in a rack with some horrificly hot Tektronix gear, and MOR gets a lot of tourists.

We have an oven inside our box to control the optical modulator to a few mK.

On a sunny day (Thu, 15 Dec 2022 06:24:51 -0800 (PST)) it happened Fred Bloggs snipped-for-privacy@gmail.com wrote in snipped-for-privacy@googlegroups.com:

My first thought it was perhaps a 'Reagan' tactic Reagan had laser weapons ready to defeat the USSR... Next US would claim it has a fusion powered space force ...

May still go! :-)

On a sunny day (Thu, 15 Dec 2022 12:02:04 +0100) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <tneurc$1610$ snipped-for-privacy@gioia.aioe.org>:

The Dutch government has just decided to build 2 new nuclear plants next to the old one, then we have 3.

The plutonium will be useful to ?rule the world? :-)

Shoot not cern have its own to power the search for the Got pqrticle?