ITER will begin fusion tests within a decade. We discuss this huge machine.
The long awaited fusion test bed, the International Thermonuclear Experimental Reactor, is under construction in Cadarache, France. ITER is an hour (70 km) North of Marseilles (South-Eastern France, not far from the Mediterranean). The facility construction is on-going in France and the machine components are being assembled all around the world.
The ITER team has ambitious goals. This is to be the first magnetic fusion machine to hold a stable plasma for 10 minutes. (They plan to extend operations to 1000 seconds, abut 16 minutes.) The fuel will be deuterium (D) and tritium (T); D is a stable type of hydrogen (H), twice as heavy as H. Fusion techniques are discussed toward the end of Stirring The Pot.
Comment 1 Fusion terms
It will reach fusion temperatures (about 150 M° C … 300 M° F) and ignite. Their goal is to use their ignited plasma to generate 500 MW of output power with a device efficiency of Q = Poutput/Pinput = 10. See Comment 1.
This exceeds the previous record set (1997) at the JET tokamak:
JET: Poutput = 16 MW, Q =0.67 .
This is hotter than any welding torch in any shop anywhere. Hotter than the center of the sun. Good thing, too, since the sun has to last tens of billions of years. If the sun had ITER temperatues, it would last only a small fraction of that.
In this post, we describe the ITER tokamak.
In our next ITER post we will use this discussion to describe a potential design feature that may limit the success of the program, though not until they have tried to reach their goals of fusion temperature; efficiency, Q; and burn times (15-20 years from now).
ITER – Overview
ITER, the pronunciation Most people in the business say eat-er. You are allowed to say it anyway you want, just be consistent.
ITER, the acronym The program started up in 1988 as the International Thermonuclear Experimental Reactor. It was an English abbreviation and the central words were thermonuclear and experimental. Although pretty good, the word nuclear had to go.
Sketch A Torus – donut shape
- The T stands for thermonuclear and could have been changeable to tokamak; its shape is a torus – Sketch A. (Looks like a bagel, a donut, or a car tire).
- The E is the important part. This machine is truly an experiment to test out ideas, not a prototype for a mass produced product like a car. But… after 120 years of building automobiles, companies that release a new model require thousands of prototype parts and vehicles for destructive testing. Thousands(?) – not going to happen. Definitely not a prototype.
ITER, the history It started in 1988 as a joint venture of 4 countries. The U.S. pulled out maybe a decade ago, then rejoined; nearly withdrew during the Obama days; our DOE just lost significant funding – want to make a bet on our presence 4 years from now? BREXIT may remove the last English speaking country. The countries currently on its guiding council are shown in the logo.
Soon, there might be no English speaking countries left, so disconnect the name from a living language. Voilá – ITER is no longer an acronym! It is okay to write it “Iter,” or “iter.”
ITER is the chosen name because it is dead Latin for The Way.
ITER, the tokamak ITER’s goal is to generate 500 MW of fusion power; support a fusion burn that lasts for 10 minutes (they will try for 1000 seconds, about 16 min); and produce 10 times more power than used by the facility (Q=10). The machine to ultimately perform these is shown in Fig 1. The left side shows its interior lined with its protective first-wall blanket. The right side depicts the blanket being installed.
Fig 1 ITER cutaway, man lower left
Fig 2 Thin slice through ITER, showing the key features
Click any figure, to see a full sized image. The colors are for identification; unless someone uses a paintbrush, the actual ITER will be metal toned, from dull to shiny gray.
Unless otherwise stated the source of the figures originate with ITER.org. We have modified and colorized most, but the basic drawings for the images are from ITER organization.
Fig 2 is a thin slice out of Fig 1. Continue reading