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ITER NEWSLINE 67
ITER is a wonderful mixture of people, cultures and knowledge resulting in an exceptional working environment. The English language is our common instrument for communication, and it swings with a broad spectrum of accents and dialects. And so does our perception of safety. It depends on our cultural background, our nationality and — very much so - on our gender.
Regardless of our wonderful and inspiring diversity, we have to come to a common understanding that safety must come first. Always and everywhere! Safety must be the first concern for whatever we do, whatever decision we take. Safety must become an integral part of our work. And this is only partly due to the fact that we are building a nuclear facility. The rapidly growing number of staff is a safety challenge and we are no longer only virtually but physically moving towards construction.
Improving ITER's safety performance will thus be an integral part of our activities this year. The safety standards established by the International Atomic Energy Agency (IAEA) form the basis for this approach. We will build on this with special training sessions for both management and staff, starting with regular safety trainings for all newcomers. Together with the French Nuclear Authorities, we will also support the management on clarifying roles and responsibilities. An effective, strong and accountable line management is the key to ensuring a safe work environment and thus to all our future success.
The cassette mover will be required to transport ITER's divertor cassettes, each weighing 9 to 10 tonnes, along a complex trajectory in order to negotiate the path along the divertor access duct from the transfer cask to the plasma chamber. This process must be executed with pinpoint accuracy since the access route is such that delicate plasma facing elements of the 3.5 metre-long x 2.5 metre-high cassette have to pass within a few centimetres of the vacuum vessel surfaces.
The 20-metre-long, 65-tonne structure is the product of a successful collaboration between the VTT Technical Research Centre of Finland and Tampere University of Technology (TUT). The design and manufacture of this core prototype has taken four years under the management of Euratom and the fusion research centres through the European Fusion Development Agreement (EFDA).
A new supercomputer will help us to understand the complex physical effects taking place inside ITER. Supercomputing is indispensable, for instance, for understanding the turbulent processes which determine the extraction of energy from the plasma at the material surfaces of the first wall of the burn chamber. The new computer, known as HPC-FF (High Performance Computing — for Fusion), will deliver computing power of about 100 teraflop/s and is optimally suited for the fusion scientists' simulation programs. The job of building and operating the computer has been given to Forschungszentrum Jülich, Germany, through the European Fusion Development Agreement (EFDA).
This together with other properties, such as their heat-dissipating capacity, makes diamonds very interesting for fusion devices. In ITER, the machine's electron cyclotron heating system will use the largest synthetic diamonds ever produced.
The electron cyclotron heating system is sometimes presented as a giant microwave cooking system. Radiofrequency waves are generated by an array of devices called "gyrotrons" located some 100 metres away from the tokamak in order to avoid perturbations from its magnetic field. A "wave guide" leads the radio waves to the chamber wall which they must pass in order to transmit their energy to the electrons inside the plasma chamber.
Since both the gyrotrons and the chamber have to remain vacuum tight, and since the radiofrequency waves propagate in a manner similar to light, the only way to get them out of the gyrotrons and into the chamber is through a window—a diamond window.
"We cannot use ordinary glass for this," explains Caroline Darbos, engineer in the electron cyclotron team, and Mark Henderson, the physicist responsible for the system. "It would melt under the heat load. About 1 MW of power has to go through these windows. And glass is not a good thermal conductor nor is it sufficiently transparent to the 170 GHz frequency we're using." Optically, thermally and structurally, diamonds are an ideal material. "They're just a bit costly," says Henderson.
ITER's heating system will require some 80 diamond windows—56 for the vacuum chamber, one for each of the 24 gyrotrons. Each window is 1.1 millimetres thick and ranges between 67 and 106 millimetres in diameter. The price for one is EUR 30,000 to EUR 100,000.
Manufacturing synthetic diamonds is a slow and quite secret industrial process based on carbon plasma—heated by an electron cyclotron system very similar to the one used for ITER—crystal growth and precision polishing. It takes about two weeks to "grow" a disk of 1.1 mm thickness.
The diamond windows for ITER are currently being tested in a joint collaboration between Forschungszentrum Karlsruhe (FZK) in Germany and the Japan Atomic Energy Agency (JAEA).
And, sorry, despite strong demand, Caroline and Mark cannot provide free samples.
The ITER Safety and Security Department had made a call for volunteers for this first aid training at the end of 2008 and six volunteers signed up for the course, bringing the total of ITER employees that have followed and obtained the first aid diploma to a total of 16.
A contact list of these 16 people will be published and distributed shortly to all ITER staff. The list will also be posted in every building. In case of an accident or sudden illness of an employee, please warn the person from this list who is nearest to the incident.
The next training course will take place in spring 2009; if you would like to take part in it, please contact Alain Le Bris.
The average precipitation for this region at this time of year is supposed to be 60 mm per month. "But then we had 140 mm of rain in December, not to mention the month of May when we were almost washed away," says Grégory Ernst, one of the engineers working for Valerian, the company in charge of the levelling of the ITER site. Grégory has been kind enough to take us on a tour around the site this morning. "See the trucks over there? They can hardly make it up the track across the hill. The soil is just too wet for the heavy machines."
The site levelling works should have been completed by November last year. But due to the bad weather in spring 2008 and the snow and ice this January, about 15 percent is still to be completed. The unexpectedly heavy rainfall also makes it necessary to increase the volume of the storm water basin from 10,000 to 13,000 cubic metres.
But there is good news as well: the access road for the "convois exceptionels" which will deliver the heavy components for the ITER machine, is being bulldozed, as well as the platform for the annex buildings and the car park. And very soon the dark brown landscape should turn into green fields. Currently, the hills and slopes of the tokamak platform are being covered with canvas mats to consolidate the top soil. As soon as the weather allows, the gardeners will move in and plant domestic seeds like lavender, rosemary and thyme.
The film, which has since achieved cult status, was about the hazards and paradoxes of time travel, about teenage romance, both in 1955 and 1985, and the friendship between the eccentric scientist Emmet "Doc" Brown and a high-school student named Marty McFly.
The time machine Doc had conceived was a modified DeLorean, an elegant stainless steel-panelled, gull-winged sports car, which was actually produced between 1981 and 1982. In the last sequence of the film, when Doc comes back from a "different future" to pick up Marty who has just returned from 1955, we get a brief glimpse of one of the components in the DeLorean's engine: a device somewhat like a coffee maker called "Mr Fusion, Home energy reactor."
We see Doc fumbling in a garbage can, finding some banana peels and leftover beer, and feeding them into the open "reactor." That is apparently all the fuel "Mr Fusion" needs to zap the DeLorean back or forward in time.
A quarter of a century later, one can retrieve more than 32,000 pages when browsing for "Mr Fusion" and "Back to the Future." The exotic device which propelled the DeLorean time machine, using banana peels and lager beer, has fascinated two generations of fans. "In many ways it represents the ultimate dream of all fusion visionaries," one author comments in a blog called Strange Horizons: "Cheap, easy, readily available energy that can easily generate the gigawatts needed for many applications—even breaking the time barrier."
The French TV channel M6 will broadcast the last part of the "Back to the Future" trilogy this Thursday, 5 February, at 8:45 p.m.
To celebrate the Chinese New Year and the start of the Year of the Ox, students between the ages of 4 and 17 had prepared a repertoire of Chinese and Korean traditional music and folk songs. With the help and support of Mr Grangier, music teacher at the International School, a full-fledged program was put together to give pupils the opportunity to show their musical talents. Some young artists sang their Chinese songs, others played their music instruments. Not only were there violin and piano players, but also a clarinet, a saxophone and a traditional Chinese violoncello, blending culture and music in an inspiring way.
And the thunderous applause at the end of the performance must have been well worth the anxiety they had no doubt felt beforehand. We certainly look forward to the next International School concert.
In last week's issue we published an article on the COMPASS tokamak achieving its first plasma at its new "home" in Prague. Up to that point we had got it right. But then we wrongly called Prague the capital of "Czechoslovakia" since 1993 when the peaceful "Velvet Revolution" took place, the country has been split into the Czech Republic and Slovakia. We sincerely apologize for this error.