Stories tagged fusion
Seems some people are still working at it.
Tags : Renewed hope for nuclear fusion
Magnetized Target Fusion
Courtesy Los Alamos fusion energy sciences Nuclear fusion has been "just around the corner" for more than 50 years. Fusion reactions occur in the sun and in hydrogen bombs. Tremendous quantities of energy can result from the fusion of hydrogen atoms into helium.
VCs bet big money on fusion power futures
Wealthy investors in California are betting hundreds of millions of dollars that the difficulties of producing power with fusion may soon be solved. The CEO of Chrysalix Energy Venture Capital thinks that "Within five years, large companies will start to think about building fusion reactors." Chrysalix invested in General Fusion, a Canadian company that says it has found a way to hurdle many of the technical problems surrounding fusion.
The company's ultimate plan is to build small fusion reactors that can produce around 100 megawatts of power. The plants would cost around $50 million. That could allow the company to generate electricity at about 4 cents per kilowatt hour, making it competitive with conventional electricity.c/net News.com
Magnetized Target Fusion
Using a technique called Magnetized Target Fusion (MTF), a current within a plasma containing lithium creates a magnetic field which allows it to be squeezed . The resulting temperature spike breaks down
the lithium into helium and tritium. Tritium, an unstable form of hydrogen, is separated and then mixed with deuterium, another form of hydrogen. The two fuse and make helium, a reaction that releases energy that can be harvested.
For updates check this General Fusion Inc. wiki.
Grand Challenges for Engineering in the 21st Century
Want to know what to do with your life. A diverse committee of experts from around the world, at the request of the U.S. National Science Foundation, identified 14 challenges that, if met, would improve how we live.
Here is their list in no particular order. You can learn more about each challenge by clicking on it.
- Make solar energy economical
- Provide energy from fusion
- Develop carbon sequestration methods
- Manage the nitrogen cycle
- Provide access to clean water
- Restore and improve urban infrastructure
- Advance health informatics
- Engineer better medicines
- Reverse-engineer the brain
- Prevent nuclear terror
- Secure cyberspace
- Enhance virtual reality
- Advance personalized learning
- Engineer the tools of scientific discovery
You can vote for which is most important
The committee decided not to rank the challenges. NAE is offering the public an opportunity to vote on which one they think is most important and to provide comments at the Engineering Challenges website
Example of a stellarator: Image courtesy: Oak Ridge National LaboratoryA 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
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