Stories tagged nuclear fusion

May
13
2010

He's fusing hydrogen isotopes in his brain right now: Such is the power of Kim Jong-Il.
He's fusing hydrogen isotopes in his brain right now: Such is the power of Kim Jong-Il.Courtesy JJ Georges
Check it out: North Korea claims to have produced nuclear fusion. Fusion has been demonstrated in laboratory experiments, and, as I understand it, fusion can be achieved in fission-based nuclear weapons, but scientists have never been able to create it on the right scale to produce lots of cheap, controlled energy (for electrical power generation, which is sort of the ultimate goal.) Except, you know, North Korea now.

(Fusion, by the way, is all about forcing two light atoms to merge together. The atoms have to release some of their components to do this, and when those components go flying off, there's a lot of energy to be had from them. More or less.)

Some folks are pointing out that North Korea is one of the poorest countries in the world, and they can barely get their national act together in a lot of other ways, so it seems very unlikely that they've made any huge advancements towards fusion power (which has eluded scientists around the world for decades). But you never know. After all, they claim that the discovery coincided with the birthday of North Korea's "Dear Leader," Kim Jong-Il, and stranger things have happened on that day—according to official biographies, a new star appeared in the sky on the day Jong-Il was born.

la la la

Jun
28
2009

Want to hear the most exciting chemistry news for the month of June?? Yes…? All right then.

A few weeks ago, the International Union of Pure and Applied Chemistry (or IUPAC if you’re feelin’ lazy) officially recognized the element 112, discovered at the GSI Helmholtzzentrum für Schwerionenforschung, as the newest element to be added to the periodic table. That’s right kids, the periodic table is gettin’ a makeover.

The new element is approximately 277 times heavier than Hydrogen, making it the heaviest element to hit the periodic table since roentgenium (which coincidentally, was also discovered by GSI). It’s been a long road for 112. Way back in 1996, Professor Sigurd Hoffman and a team of 21 scientists at GSI created it with an accelerator. Six years later, they were able to produce another atom. Finally confirming the discovery, accelerator experiments at the Japanese RIKEN produce more atoms of 112.

How does an accelerator make an atom, you ask? Well, zinc ions are fired towards a lead target with the help of a 120-meter long particle accelerator. Once they hit, the zinc and lead nuclei merge in a nuclear fusion to form the nucleus of a new element.

Cool.The accelerator: The target wheel equipped with lead waiting to be irradiated with zinc ions
The accelerator: The target wheel equipped with lead waiting to be irradiated with zinc ionsCourtesy A. Zschau, GSI

And now for the fun part. Over the next few weeks, the scientists from the discovery team will deliberate on the name of element 112. After its been submitted to IUPAC, it will be assessed and then officially be crowned the newest member of the periodic team.

Mar
15
2007

Example of a stellarator: Image courtesy: Oak Ridge National Laboratory
Example of a stellarator: Image courtesy: Oak Ridge National Laboratory
A research team at the University of Wisconsin-Madison has brought the world another step closer to the possibility of harnessing fusion energy.

Professor David Anderson and his assistant John Canik have constructed a new type of stellarator that they claim will overcome the problem of energy loss that is inherent in the machines.

A stellarator is strange-looking toroidal (doughnut-shaped) device comprised of a chamber wrapped in magnetic coils and used to confine a hot plasma so as to sustain a controlled nuclear fusion reaction. A similar machine, called a tokamak, is also used in the quest for fusion energy. But both machines have their problems. A tokamak uses plasma currents to confine the plasma inside magnetic fields and, because of this, can experience “disruptions”. A stellarator, on the other hand, uses no currents so disruptions don’t occur, but the machine tends to lose energy at a high rate –a process known as transport-which makes it unable to reach the high temperatures necessary for nuclear fusion .

So Anderson and Canik set out to come up with a new configuration utilizing the best features of both machines. The result was the Helically Symmetric eXperiment (HSX), a new type of stellarator that uses a quasi-symmetric magnetic field to confine the plasma.

Essentially the stuff of stars, plasma is a hot ionized gas that- if heated to a high enough temperature- can cause hydrogen atoms to fuse themselves into helium atoms, the very process that powers the sun’s energy. If fusion can be achieved in the lab, it would mean a limitless new source of energy.

Anderson and Canik’s idea was to design and construct a machine using quasisymmetry that would effectively reduce transport, and according to their recent research, that’s exactly what the HSX does.

"This is the first demonstration that quasisymmetry works, and you can actually measure the reduction in transport that you get," says Canik.

The research results appeared in a recent issue of Physical Review Letters, and for Prof. Anderson the results couldn’t have been better.

"We all thought the machine would do what it's turning out to do, but there are a million reasons why it might not: the theory might be wrong, (or) we might have built it badly," Anderson said. "But everything is panning out and supporting the fact that the ideas on which it was based were correct, and really points the way of the future for the stellarator."

The seventeen years of work seems to be paying off for the team, which now hopes to determine how much symmetry in the coils is necessary to attain low rates of transport.

"It's an exciting field. It's something where one can contribute positively to mankind with an energy source that's completely sustainable, doesn't involve nuclear proliferation or radioactive waste, with a limitless fuel supply," says Anderson. "Plus, the machines look cool."

MORE INFORMATION

Story on Physorg.com
Princeton Plasma Physics Laboratory
Oak Ridge National Laboratory
Plasma info
Tokamak info
Stellarator info
Nuclear fusion info