New project aims for fusion ignition

May 10, 2010 by David L. Chandler, Massachusetts Institute of Technology
Exterior view of the Ignitor fusion reactor, whose core will be built in Italy and external housing built outside Moscow, where it will be installed. Image courtesy of Bruno Coppi

Russia and Italy have entered into an agreement to build a new fusion reactor outside Moscow that could become the first such reactor to achieve ignition, the point where a fusion reaction becomes self-sustaining instead of requiring a constant input of energy. The design for the reactor, called Ignitor, originated with MIT physics professor Bruno Coppi, who will be the project's principal investigator.

The concept for the new reactor builds on decades of experience with MIT’s Alcator fusion research program, also initiated by Coppi, which in its present version (called Alcator C-Mod) has the highest magnetic field and highest plasma pressure (two of the most important measures of performance in magnetic fusion) of any , and is the largest university-based fusion reactor in the world.

The key ingredient in all fusion experiments is plasma, a kind of hot gas made up of charged particles such as atomic nuclei and electrons. In fusion reactors, — usually of isotopes of hydrogen called and — are forced together through a combination of heat and pressure to overcome their natural electrostatic repulsion. When the nuclei join together, or fuse, they release prodigious amounts of energy.

Ignitor would be about twice the size of Alcator C-Mod, with a main donut-shaped chamber 1.3 meters across, and have an even stronger . It will be much smaller and less expensive than the major international fusion project called (with a chamber 6.2 meters across), currently under construction in France. Though originally designed to achieve ignition, the ITER reactor has been scaled back and is now not expected to reach that milestone.

The Ignitor reactor, Coppi says, will be “a very compact, inexpensive type of machine,” and unlike the larger ITER could be ready to begin operations within a few years. Its design is based on a particularly effective combination of factors that researchers unexpectedly discovered during the many years of running the Alcator program, and that were later confirmed in experiments at other reactors. Together, these factors produce especially good confinement of the plasma and a high degree of purity (impurities in the hot gases can be a major source of inefficiency). The new design aims to preserve these features to produce the highest plasma current densities — the amount of electric current in a given area of plasma. The design also has additional structures needed to produce and confine burning fusion plasmas in order to create the conditions needed for ignition, Coppi says.

Coppi plans to work with the Italian ministry of research and Evgeny Velikhov, president of the Kurchatov Institute in Moscow, to finalize the distribution of tasks for the machine, the core of which is to be built in Italy and then installed in Troitsk, near Moscow, on the site of that institute’s present Triniti reactor. Velikhov, as it happens, is also the chair of the ITER council. Coppi says of these two different programs, “there’s no competition, we are complementary.”

Although seen as a possible significant contributor to the world’s energy needs because it would be free of greenhouse-gas emissions, practical fusion power remains at least two decades away, most scientists in the field agree. But the initial impetus for setting up the Alcator reactor in the 1970s had more to do with pure science: “It was set up to simulate the X-ray stars that we knew at that time,” says Coppi, whose research work has as much to do with astrophysics as with energy. Stars are themselves made of plasma and powered by fusion, and the only way to study their atomic-level behavior in detail is through experiments inside fusion reactors.

Internal cutaway view of the reactor, showing the donut-shaped cavity that houses the hot plasma where fusion will take place. Image courtesy of Bruno Coppi

Once the reactor was in operation, he says, “we found we were producing plasmas with unusual properties,” and realized this might represent a path to the long-sought goal of fusion ignition.

Roscoe White, a distinguished research fellow at the Princeton Plasma Physics Laboratory, says that “the whole point of Ignitor is to find out how a burning plasma behaves, and there could be pleasant or unpleasant results coming from it. Whatever is learned is a gain. Nobody knows exactly how it will perform, that is the point of the experiment.” But while its exact results are unknown, White says it is important to pursue this project in addition to other approaches to fusion. “With our present knowledge it is very risky to commit the program to a single track reactor development — our knowledge is still in flux,” he says.

In addition, he says, “the completion of ITER, the only currently projected burning plasma experiment, is decades off. Experimental data concerning a burning would be very welcome, and could lead to important results helping the cause of practical fusion power.” Furthermore, the Ignitor approach, if all goes well, could lead to more compact and economical future reactors: Some recent results from existing reactors, plus new information to be gained from Ignitor, “could lead to reactor designs much smaller and simpler than ITER,” he says.

Coppi remains especially interested in the potential of the new reactor to make new discoveries about fundamental physics. Quoting the late MIT physicist and Institute Professor Bruno Rossi, Coppi says, “whenever you do experiments in an unknown regime, you will find something new.” The new machine’s findings, he suggests, “will have a strong impact on astrophysics.”

Explore further: Fusion technology: from ANU to the world

More information: www.frascati.enea.it/ignitor/

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17 comments

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Quantum_Conundrum
3.2 / 5 (5) May 10, 2010
Haven't read past the first paragraph yet, gave it 5 stars not because of the article, but because of the concept and it's ramifications.

This would represent maybe the greatest technological discovery in the history of humanity.

With fusion power mining comets for hydrogen from water-ice and methane ice (we don't want to deplete Earth's oceans,) would become the basis of a new world economy.

I wonder how many people in fossil fuels and "alternative" energy fields, as well as "paper work" jobs this would instantly put out of work if this reactor is successful?

Bring on the future "semi-utopian" economy, where Fusion powered robots do 99.99% of work, and humans pretty much just invent new robots and new jobs for robots to do...

C'mon baby be successful!

I hope to God they get this to work very soon!
El_Nose
3 / 5 (2) May 10, 2010
@Quantum_Conundrum

I guess you've never heard of the ITER project then ??? http://www.iter.org

--- get some more info
jamey
3 / 5 (4) May 10, 2010
Fusion power has been 20 years away for the last 50 years. It's as bad as AI. This is also a very long way from Back To The Future's "Mr. Fusion".

ITER, Tokamacs, a dozen other fusion projects have been under way. Personally, I'll buy into it when someone comes up with one that doesn't involve power scales on the order of the entire US Grid (admitted, on short time frames) to ignite things.
solrey
3.7 / 5 (3) May 10, 2010
It appears that Lawrenceville Plasma Physics is on schedule to achieve net energy gain sometime next year with their version of a Dense Plasma Focus. Focus Fusion uses Rogowski coils to convert the energy from ion and electron beams, generated by aneutronic fusion in the plasmoid, directly into electricity. In contrast to this Ignitor reactor, and others of the Tokamak design, which still just convert the energy, from neutrons I believe, into heat to produce steam to drive turbine generators.

http://www.focusfusion.org/
trantor
2 / 5 (6) May 10, 2010
lots of bullshit. The ultimate fusion project is the Polywell, by Bussard. (the same guy who invented the concept that became known as Bussard Ramjet)
NeuroPulse
2 / 5 (1) May 10, 2010
Greetings,

It is unclear to me what the difference in approaches to achieving ignition are between the Ignitor and ITER. Anyone?

Thanks
dirk_bruere
4 / 5 (1) May 10, 2010
The major difference between Igniter and ITER is size and cost. ITER is insanely expensive and (in terms of volume) around 50x bigger
Shootist
May 10, 2010
This comment has been removed by a moderator.
Foundation
4.3 / 5 (3) May 11, 2010
As far as I know ITER is still on track to be operational by 2018. How is that decades off?

It's great to see more effort being put in fusion power though.
kevinrtrs
1.2 / 5 (5) May 11, 2010
Juat a thought: If it's this difficult to start fusion by multiple groups of scientists, how did it start in stars?

I sincerely hope they make some [very safe] progress with this work - we certainly can do with a clean-burning[well relatively speaking, compared to nuclear fission] power generation technology.
El_Nose
4.3 / 5 (4) May 11, 2010
@kevinrtrs ---

gravity started the fusion reaction in stars...

and while fusion will be cleaner than fision it is by no means perfectly clean. The housing of tokamacs become serious environmental concerns as does anything within close proximity of the plasma generated. While overall this is significantly less radioactive matter than that generated from spent nuclear fuel the technology does create some radioactive waste. -- Just not very much.
Bookbinder
not rated yet May 11, 2010
Thanks all for comments which are comprehensible for us amateurs! An enjoyable read.
Alizee
May 11, 2010
This comment has been removed by a moderator.
Zuls
5 / 5 (2) May 12, 2010
@ Quantum Conundrum

You commented on another article that you can't see an application for faster computers and yet you want a utopian world where robots do all the work. There's your application right there -- robots can easily benefit from computers orders of magnitude faster than what we have now...
tvdog12345
not rated yet May 16, 2010
@Quantum_Conundrum:

Energy density of hydrogen (in fusion): 645,000,000 MJ/kg [source: http://en.wikiped..._density]

Total world energy consumption in 2008: 474 EJ = 474,000,000,000,000 MJ [http://en.wikiped...sumption]

Therefore, the amount of hydrogen needed to meet total world energy demand is: 734,884 kg

The total amount of hydrogen in the world's oceans is: 1.65 x 10^20 kg = 165,000,000,000,000,000,000 kg [http://answers.go...696.html]

Therefore, at current rates of energy use, the hydrogen in the oceans would last: 224,525,231,192,950 = 224.5 trillion years

Put another way, it would be 2.25 trillion years before mankind used even 1% of the hydrogen in the oceans for fusion power. Hence, there would be no need to mine water on asteroids to avoid depleting the oceans.
enantiomer2000
4 / 5 (1) May 16, 2010
@solrey:

Yes I am excited about Focus Fusion, but Lawrenceville still has a couple of things they still need to prove before their theory is validated. The nice thing is that they are looking at proving it this year or early next year, rather than a nebulous "50 years away" from many of the other fusion projects.
rbrtwjohnson
5 / 5 (1) May 17, 2010
After more than 30 big tokamak experiments world-wide it is already possible to conclude that neutral plasma confinement is a flawed concept. Furthermore, tritium is rare in nature, radioactive, economically unaffordable. Hence, I think a well-conceived aneutronic fusion reactor can be much more promising to harness the fusion power.
http://www.crossf...iew.html

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