Nuclear Fusion Discovered

prostoalex writes "Both USA Today and The New York Times are reporting on research group from UCLA led by Seth J. Putterman which has discovered a form of nuclear fusion. The impact of the discovery? 'While the device is probably too inefficient to produce electricity or other forms of energy, the scientists say, egg-size fusion generators could someday find uses in spacecraft thrusters, medical treatments and scanners that search for bombs.' The findings are published in Nature magazine."

Comments

great result, but not really a "discovery"

[gevmage]

First of all, humans "discovered" fusion in 1953 with the first fusion bomb, or "hydrogen" bomb. What this speaks of is controlled fusion.

Secondly, this isn't fusion on even a battery scale; this is a few thousand atoms per second or so. So unfortunately, it's not a matter of scaling up to produce a reactor. The amount of energy being put into the system dwarfs by thousands of times the energy from fusion being put out.

Third, this isn't even the discovery of table-top laboratory scale fusion. As an undergraduate, I worked on a muon catalyzed fusion experiment at TRIUMF in Vancouver. By the time I was working on the experiment in 1994, the fusion reaction in the experiment was so well understood that it was being used to analyze other properties of solidified Hydrogen.

And I'm afraid it's a little bit of a dodge to say it's "at room temperature". The article doesn't say this, but presumably this takes place in a vaccum, where temperature is basically undefined in any conventional sense.

So a very nifty result, but not a discovery, I'm afraid. It will very likely be useful to study the fusion process, or perhaps other things as well.

Re:great result, but not really a "discovery"

[saw]

>Third, this isn't even the discovery of table-top laboratory scale fusion. As an undergraduate, I worked on a muon catalyzed fusion experiment at TRIUMF in Vancouver.

Just to be nit-picky: While the cell in which the muon catalyzed fusion takes place may fit on a normal table-top, it would take an awfully large table to hold the proton accelerator, the production target, and the system of vacuum pipes and magnets that decay the pions and select and degrade the muons.

Re:great result, but not really a "discovery"

[nietsch]

There is a feasible fusion generator that you failed to mention, invented in the '60 by the inventor of television, Philo Farnsworth.

Have a look at it here:
http://en.wikipedia.org/wiki/Farnsworth-Hirsch_Fus or

"Unlike most controlled fusion systems, which slowly heat a magnetically confined plasma, the fusor injects "high temperature" ions directly into a reaction chamber, thereby avoiding a considerable amount of complexity.

When Farnsworth-Hirsch Fusor was first introduced to the fusion research world in the late 1960s, the Fusor was the first device that could clearly demonstrate it was producing any fusion reactions at all.

It has since been abandoned as a potential fusion generator, since you still have to put in more energy than comes out of it (like every other fusion technology thus far). Some suggest this may be because it is too simple and offers less ways to spend lots of money on it (and acquire status and research grants by doing so).

And humans discovered fusion in the morning, when they opened their eyes and looked at the sun...

Re:great result, but not really a "discovery"

[merlin_jim]

I'd just like to add a few points.

This method of fusion has been known for at least a decade. But the energy efficiency is so low that it's just not a candidate for power generation. Like the article says, this is primarily targetted as a neutron source. It might be able to be scaled above the break even point, but not without some pretty innovative features.

The basic of it is you get a copper plate, attach it to a special crystal, heat it with a tungsten filament, and immerse it in deuterium gas. The heated crystal strips electrons from the deuterium gas, and the ions are accelerated towards an erbium-deuterium target.

I imagine most of your energy is lost as waste heat. And while this is cold fusion, this is not room temperature fusion. Cold fusion is any fusion that is not heat-pressure catalyzed. While heating is involved here, the energy from the heat pressure is not directly used to bring deuterium nuclei together...

Slashdot: Nuclear Fusion Dupe Discovered

[Anonymous Coward]

Anonymous Coward writes "Both Slashdot and Slashdot are reporting on the same story about the discovery of a form of nuclear fusion at UCLA. The impact of the dupe? 'While the dupe is probably too inefficient to produce new discussion or other forms of insight, the editors say, it could already find uses ad revenue creation through hundreds of comments about it being a dupe.' The findings are published in anti-slash.org."

Re:Slashdot: Nuclear Fusion Dupe Discovered

[FortKnox]

The truely frustrating part is the moment I saw this a good 15 minutes ago (using my subscription plume to see stories early), I wrote an email immediately to the requested address (daddypants -at- slashdot) and told of the dupe.

This was 'supposed' to help them clean up dupes, yet we find that they are not only failing to check dupes, tehy are also failing to check the account so that those of us (that are paying, not being paid) can help out...

Dupe

[bunratty]

Now if Slashdot could only fuse duplicate stories into one...

Again?

[MaestroSartori]

Can you really discover something twice on consecutive days???

"My god, that discovery is even better than it was yesterday! I'm glad we discovered it again. Let's discover pepperoni pizza next!"

Only on Slashdot ;)

Repost

[shamowfski]

Doc Brown: "Marty we've gone back in time!" Marty: "No Doc, It's just a repost."

Re:The impact of the discovery?

[Thud457]

That's fission. Fusion would lead to fewer dupes.

Let's see

[khrtt]

First of all, this is a dupe

Secondly, they haven't discovered fusion, they have invented a new type of fusion-based neutron generator. Several types of neutron generators are commonly known, and some are simple enough that you could build a working one in your garage. All of them use the same principle, more or less - high voltage, on the order of 100kV, accelerates deuterium ions into a deuterium (or tritium) containing target. So does this one.

The novelty is that they used a pyroelectric crystal to generate the high voltage. This makes the device small and self-contained, with no need for high-voltage electric machinery. All you do is heat-cycle the crystal with some 50 degree C temperature span, and you get fusion neutrons.

Note that like all fusion devices to date (other than bombs), this gadget produces a lot less fusion energy than is put in, and brings us no closer to having a fusion-based power source.

But it's a neat idea. And it makes a neat cheap laboratory neutron source.

Re:Fusion, time travel...

[dr_dank]

Fusion, time travel... Multiple posts. Cmon.

Thats what usually happens when they get Slashdot up to 88 miles per hour.

And humans discovered fusion in the morning, when

[dpilot]

Given the state of the modern patent system...

After patenting fusion, would you try to license or sue:

God, for infringing on your patent, with "billions and billions" of offending instances?

Everyone else on Earth, for receiving the benefits of the unlicensed fusion source?

Summary of the actual nature article

[francisew]

Their setup: The 'crystal' mentioned in the mainstream articles, is a z-cut lithium tantalate crystal (LiTaO3), with the negative axis facing outward onto a hollow copper block. A tiny tungsten probe (80 microns long and 100 nm wide) is then attached to the other crystal face. This probe acts as a tiny mast for the electric field so that there is a powerful electrical field at the tip of the probe. Then there were a bunch of fancy neutron-counters and single-photon counters bundled around it.

What they did: First they added deuterium gas (at 0.7 Pa) and then cooled the crystal down using liquid nitrogen (to 240 K). Then they used a little heater to increase the chamber temperature slowly.

What happened: Less than 3 minutes later, and still below 273 K (0 degrees Celcius), the neutron signal rose above the background level. There were x-rays coming from the probe tip, and a whole bunch of neutrons. After a few more minutes, the electric field was so strong that it caused arcing between the probe tip and the enclosure (because they kept heatingthe crystal, and the field thus kept getting stronger). The arcing stopped the process (and I'd guess it damages the crystal?).

They added a few links in the article to previous papers: a pdf describing the concept they are trying to harness, another pdf with more about how they use the crystals with the deuterium gas, and a brief abstract.

I think this is pretty cool. I bet/hope that before long (within 10 years), this will be powering small extrasolar probes.

Pretty neat stuff. I don't even mind dupe posts when they're on such important stuff.