One step closer to controlling nuclear fusion
Using a heating system, physicists have succeeded for the first time in preventing the development of instabilities in an efficient alternative way relevant to a future nuclear fusion reactor. It’s an important step forward in the effort to build the future ITER reactor.
Nuclear fusion is an attempt to reproduce the energy of the Sun in an Earth-based reactor system. When gas is heated to several million degrees, it becomes plasma. Sometimes in the plasma, an instability will appear and grow large enough to perturb the plasma, making it vibrate despite the presence of the magnetic field in which it is contained. If the plasma touches the walls of the reactor, it will cool rapidly and create large electromagnetic forces within the structure of the machine.
The challenge is to reduce the instabilities deep within in the interior of the plasma so that they don’t amplify, while at the same time allowing the reactor to continue to function normally. Thus it is necessary to work within the specific configuration of these fusion reactors, where the plasma is strongly confined by a magnetic field. By adjusting an antenna that emits electromagnetic radiation, physicists from EPFL’s Center for Research in Plasma Physics were able to quench the instabilities when they appear, in the precise region where they are forming, and without perturbing the rest of the installation.
From theory to practice
The physicists first conducted simulations to verify the extent to which specific radiation frequencies and locations of application would suppress the growth of instabilities. Then they carried out tests to confirm their calculations. The beauty of their approach is that they were able to use antennas that are used as part of the system to heat the plasma, and that are already present in the Joint European Torus (JET), the largest reactor currently in use. Surprisingly, the simulations and the tests showed that heating and instability suppression can be combined, by aiming the radiation slightly off-center in the plasma.
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The “typical American” seems to have the long-range planning skills of a gnat.
http://www.popsci.com/science/article/2011-05/jeff-bezos-invests-195-million-nuclear-fusion-technology
[font size=4]This is the fusion company that PopSci said might save the world[/font]
By Clay Dillow Posted 05.05.2011 at 4:43 pm
[font size=1]Home-Brewed Fusion General Fusion’s proof-of-concept device in the company’s austere headquarters, in Burnaby, British Columbia John B. Carnett
[font size=3]Bring up the prospect of fusion power, and often eyes glaze over. It’s not that it’s not a thrilling prospect--cheap and inexhaustible energy would solve a lot of problems here on planet Earth--but it’s been such a pipe dream for so long that it’s often hard to make people care. But at least one person with a proven track record in recognizing potential when he sees it has taken an interest in a fusion-powered future: Amazon founder and gazillionaire Jeff Bezos has thrown $19.5 million <http://www.greentechmedia.com/articles/read/jeff-bezos-invests-in-nuclear-fusion-but-whens-the-demo/ > to Canada’s General Fusion to fund further research.
PopSci wrote about General Fusion <http://www.popsci.com/scitech/article/2008-12/machine-might-save-world > back in late 2008, when the company was just getting underway in its efforts to completely upend the global energy paradigm in an office park British Colombia. At the time the company said it could provide data that would prove that fusion is indeed possible within three to four years. We haven’t seen that (publicly) yet, but whatever Bezos has seen apparently impressed him.
General Fusion is pursuing what is called Magnetized Target Fusion. In a few words, this technique essentially uses a magnetic field and plasma to break lithium down into helium and tritium, which is then separated and mixed with deuterium, which then fuses into helium (that’s a wild oversimplification, in case you were wondering).
That fusion of tritium and deuterium--both forms of hydrogen--into helium releases a huge burst of energy, which can be harvested into electricity. So where you’ve basically started with cheap and plentiful lithium, you end up with a massive amount of energy and harmless gas as a byproduct--no radioactive mess to clean up (or ceaselessly worry about).
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http://www.emc2fusion.org/
They’ll be ready in 30 years too!
https://lasers.llnl.gov/about/missions/energy_for_the_future/life/
Tackling the Global Energy Crisis[/font]
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[font size=4]Delivering Fusion Energy Soon Enough to Make a Difference[/font]
[font size=3]Despite fusion's potential benefits for a low-carbon energy economy, the long timescales typically associated with fusion development have excluded it from mainstream energy policy considerations. The United States is in a unique position to change this paradigm, and deliver laser fusion power stations on a timescale that matters—with LIFE.
The path to LIFE is a four-step process:
- NIF: Construction and operation of a laser facility at the scale required for energy production (Achieved 2009)
- Ignition: Demonstration of net energy gain from fusion fuel (On target, by end of 2012)
- LIFE demonstration: Integration of all the technologies required for a power station (Planned for mid-2020s)
- Commercial LIFE fleet: Rollout of LIFE plants onto the electric grid (Late 2020s and beyond)
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Instead of a fission bomb detonator one might use conventional explosives and very powerful magnetic fields. A nation might skip the messy business of uranium enrichment or plutonium production.
We have a number of global problems to deal with.
If there should be a global scale social collapse, that might make something like rolling out large fusion facilities difficult.
However, you can follow LIFE progress here:
https://lasers.llnl.gov/newsroom/project_status/index.php
[font size=4]December
DT Experiment Sets Record for Neutron Yield[/font]
[font size=3]The National Ignition Campaign (NIC) team completed a layered cryogenic deuterium-tritium (DT) shot on Dec. 15; 190 NIF beams delivered 1.41 megajoules (MJ) of ultraviolet light to the hohlraum. Good target diagnostic data were acquired on all electronic detector diagnostics, including a time-integrated neutron image on the Neutron Imaging System and a time-resolved implosion x-ray image on the Active Readout in a Neutron Environment (ARIANE) diagnostic.
[font size=1]Jesse Hamblen installs the CCD (charge-coupled device) camera system in NIF's ARIANE x-ray imaging diagnostic. ARIANE uses the CCD detector to electronically capture and record data in high-neutron-yield experiments.[/font]
Data from the diagnostics indicated that neutron yield was about 7 × 10[font size="1"]14[/font] (700 trillion), a record yield for this type of experiment.
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