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ITER NEWSLINE 122
At the end of its two-day assessment, the MAC reached the conclusion that "this schedule, under which First Plasma would be attained in early November 2019, appears to be technically-credible and achievable, and in line with delivery dates that the Domestic Agencies assess to be realistically achievable."
In its report to the ITER Council, the MAC writes: "The ITER Organization is invited to use the 2 November 2019 schedule as the basis for its further preparation of the overall ITER Baseline Documentation [..] with a view to its adoption at the ITER Council meeting on 16-17 June 2010."
As soon as the ITER Director-General Kaname Ikeda and his Principal Deputy Director-General Norbert Holtkamp had finished their progress reports, it became clear that there was appreciation for work accomplished. "We are pleased to see the improvements made," said Richard Hawryluk, the leader of the US delegation who was the first to comment. "We are happy to note that things are finally converging," Pucadyil Ittoop John, leader of the Indian delegation, added. Martin Drew, speaking on behalf the European delegation, voiced the opinion that "we are in a much healthier position then we were six months ago."
Gyung-Su Lee, Chairman of the MAC, showed himself satisfied with the outcome of this seventh meeting. "The objectives have been fulfilled," he stated. "This consensus on the improved Updated Schedule was an important step. But we are not yet there. Now the figures have to be added to this schedule in order to finalize the Baseline documentation for the Council meeting in June. This will be quite a challenge, but it can be done."
"With this signature, worth EUR 31.3 million, we have completed the three Procurement Arrangements for the divertor's plasma-facing components," explained Mario Merola, Internal Components Division Head. "What remains is the actual cassette body, which is the steel structure, which supports the plasma-facing components and routes the water coolant. But compared to the plasma-facing components, whose design is a real technical and engineering challenge because they have to withstand the extreme heat loads inside the vacuum vessel of up to 20 MW per square metre, this is a relatively easy task."
But before it was time to uncork the champagne and to raise the glasses, a second Procurement Arrangement was signed for the central solenoid magnet, the backbone of ITER's magnet system. Ned Sauthoff, the Project Manager of the US Domestic Agency, signed the documents alongside Kaname Ikeda. The procurement, bringing the total number of signed Procurement Arrangements up to 34, is worth about EUR 88 million.
Related stories: See this week's featured video and "Packing a Punch."
The ITER central solenoid will take advantage of every bit of space from its central position in the machine—right up to the ten millimetres of radial clearance it shares with the surrounding toroidal field magnet system—to achieve the highest value of stored magnetic energy possible.
The central solenoid is the key component that will allow a powerful current to be induced in the ITER plasma and maintained during long plasma pulses.
Two parameters that are important to obtaining maximum plasma current drive are magnetic field and the area of the solenoid. The higher the magnetic field and the larger the area of the magnet where it exists, the greater the magnetic flux, the quantity that characterizes current drive capability.
The ITER central solenoid—with a diameter of 4.3 metres and a height of 18 metres—will top the charts as the largest solenoid ever built for a fusion device. Maximum field of 13 tesla will be reached in the centre of the central solenoid. That's the strongest of all ITER magnet systems, and equivalent to 280,000 times the magnetic field of the Earth.
Solenoids are lengths of coiled wire that generate magnetic fields when electric current is passed through them. Electricity and magnetism are closely related: place two solenoids one inside the other, and the variation of electrical current in the first will produce a variation of electrical current in the second.
ITER and other tokamaks essentially act as large transformers, where the central solenoid is the primary winding, and the plasma the secondary winding.
Solenoids are responsible for driving the plasma current in all tokamak devices. At the largest currently-operating tokamak (JET in the UK), the solenoid initiates plasma currents of about 5 megaamperes (MA) for plasma pulses lasting up to 60 seconds. The plasma volume in ITER will be eight times greater than in JET, and consequently the "drive" required from the central solenoid will be much greater as well. Stored magnetic energy of 6.4 GJ in the central solenoid will initiate and sustain a plasma current of 15 MA for durations of 300-500 seconds.
But the role of the central solenoid doesn't end there. As the high-intensity current circulates within the tokamak, electrons and ions in the plasma will become energized and collide. Collisions create 'resistance' that produces heat. This heating effect, known as ohmic heating, will contribute to bringing the ITER plasma to the temperatures close to 150 million degrees Celsius necessary for fusion to take place.
The central solenoid will also assist in shaping the plasma. Physicists prefer a D-shaped plasma to a circular one; by 'tweaking' current applied to the top and bottom central solenoid modules (see below), operators will use variations in magnetic field to elongate the cross section of the ITER plasma and achieve this optimum shape.
The "central" solenoid is indeed central to the success of ITER operation. Its combination of performance parameters makes it one of the most complex and challenging magnet systems ever built. Strong team effort will be required from all parties throughout the design, fabrication and assembly process.
The "electrical ballet" of the central solenoid
In order to induce powerful current in the plasma, the ITER central solenoid will have to carry a lot of current—46 kA to be precise.
During "ramp-up" at the beginning of an experiment in ITER, voltage will be applied to the six central solenoid modules until they each reach 40 kA of current. This "pre-magnetization' period will last for approximately six minutes.
The current will then be discharged to initiate a plasma pulse. From this moment—until the end of the cycle—the six central solenoid modules will act independently, each following an individual current profile. In certain modules, current will drop to zero directly, before being ramped up again in the reverse direction; others will decrease more progressively; still others will change current directions twice. Only the two central modules, CS1U and CS1L, act as a pair. Toward the end of the cycle, maximum current of 46 kA is reached in some modules.
These variations in current between the different modules give scientists the tool they need for plasma shaping. Current variation, which induces magnetic flux variation, is the key to producing the large plasma current needed for ITER. "What we want in ITER," says Paul Libeyre, Central Solenoid and Correction Coil Section Leader, "is maximum flux variation to allow long plasma pulses."
A central solenoid with fixed current would never work. "Having the possibility of varying the current differently in each of the six modules allows a lot of different scenarios," Paul explains. "It's like allowing dancers to perform individual choreographies, instead of marching all together like in a military parade."
Operators will also use current variation in the top and bottom modules to influence the shape of the plasma for best performance.
For the duration of each 1,000-second plasma pulse during ITER operation, the ballet of increasing and decreasing voltage will continue in the modules, carefully choreographed to build the plasma current up to a plateau of 15 MA for around 400 seconds, before ramping down again to zero.
30,000 plasma pulses are foreseen for the ITER experimental campaign, during which the central solenoid will be "ramped up" to initiate plasma current and "ramped down" again at the end of each pulse.
This Friday, the ITER Organization and the fusion community commemorated two of their long-time team members: Arturo and Beatrice Tanga. The couple was killed in a car accident last December (see Newsline # 113). In order to honour their contribution to fusion research, and also to honour them as valued colleagues and dear friends, more than one hundred people congregated at Cadarache for a tribute. Many more listeners joined the ceremony via a live video link.
"He is greatly missed," ITER Director-General Kaname Ikeda said in his opening remarks, after which he handed the microphone over to Ruggero Giannella, a fusion scientist and lifetime friend of Arturo and Beatrice. In a very emotional speech—both for the family and himself—he surveyed the couple's early life and work at the University of Rome and later in Frascati. "Arturo," Giannella said, "was an experimentalist by heart." Working with Arturo was "like climbing a mountain," he continued. "It required some exercise and it could lead to exhaustion. But it was always worth it."
The afternoon's second speaker was Jean Jacquinot, Department Head at JET during the time when Arturo was in charge of the machine's operations. In addition to having a brave and creative mind, Jacquinot said, some would be surprised to learn that Arturo had managerial skills "which were not to be stopped by bureaucracy." He remembered the year of 1986, four years after the H-mode had been discovered on the ASDEX machine in Garching, Germany. Inspired by the German experiment, Arturo proposed to try something similar on JET—which would mean some serious modification to the machine. But as Arturo was "an experimentalist by heart," as Ruggero Giannella had stated before, he did not give up. The last skeptics were proven wrong when the achievements resulting from this courageous move were acknowledged as the highlight of the 1986 IAEA conference in Kyoto, Jacquinot said.
Later, Arturo broke the JET record taking the tokamak to 7 MA limiter operations, although JET was only designed to take 3.5 MA. "But," Jacquinot added, "to be fair, I have to mention that with 6.3 MA, Arturo also holds the record for the biggest disruption ever provoked on JET lifting the machine off the ground and leaving its rails dislodged." An incident that was later commented by then Director Paul-Henry Rebut as "weakness that needed to be identified and rectified."
Despite all the tears and sorrow that filled the auditorium in Cadarache Friday afternoon, this remark made the audience smile.
Dhiraj Bora, Head of ITER's CODAC, Heating & Current Drive Department was the next speaker emphasizing Arturo's contribution to ITER's neutral beam system. "We will not let you down," Bora promised, saying that the work would continue.
Last but not least, John Edward Allen from Oxford University honoured the work of Beatrice Tanga, a dedicated plasma scientist herself. Whereas her husband's focus was in heating high-temperature plasmas, Beatrice's interest was on low-temperature plasmas—rather at the other end of the mercury scale.
Last Friday 12 March at La Fenière, the prestigious "Red Ribbon" was awarded to CEA-Cadarache Director Serge Durand in recognition of his achievements during his 34-year career in the nuclear world, both civilian and military.
An engineer turned "industrial architect," Serge Durand played a key role in the development of France's nuclear deterrent and was instrumental in the construction of Laser MegaJoule, the inertial fusion facility being established near Bordeaux. He has been heading CEA-Cadarache since 2006.
"You are a man of courage, faith and action," said CEA Administrator General Bernard Bigot as he pinned the medal to the new chevalier's lapel, "the kind of man this country needs."
Fusion has indeed played a big role in the life of GS Lee. He studied physics at the Seoul National University in Korea before continuing at the University of Texas at Austin in the USA. His Ph. D. thesis on plasma turbulences in tokamaks was written under the guidance of the "Pope of Plasma" Marshall Rosenbluth and Pat Diamond. GS went on to work as a member of the research staff at Oak Ridge and then at MIT, before returning to Korea to take up the post of Director of the Joint Research Division of the Korea Basic Science Institute. From 1996-2005 he was the Principal Investigator of the prestigious KSTAR project and became the Director-General of ITER Korea in 2007 (see link)—a post he handed over to Kijung Jung when he became President of the National Fusion Research Institute of Korea in September 2008. He is also the current Chairman of the International Fusion Research Council of the IAEA.
More recently, GS took over as Chair of the ITER Management Advisory Committee (MAC), one of the two subcommittees of the ITER Council, the Project's governing board.
Looking at his impressive credentials, it becomes evident that GS has devoted a major part of his life to developing fusion as a future energy source. He believes in fusion, without a doubt, but there is more to add. GS is also a passionate Christian who devotes his Sundays to worship in his hometown Daejeon. And it stems from this religiousness when he says that "time should not be wasted." That, he adds, holds in many respects—also for ITER.
"Yes, we could have done better," admits Lee. "I guess that all of us are unsatisfied at times with the slow progress and I can understand that people watching us are cautious. But now that we have agreement on the table for the project's schedule there is light at the end of the tunnel. Without a finalized Baseline we were adrift. But now we will be able to benchmark our targets: What do we want to build, when do we want to finish and what resources do we need? We are not yet there, but at least we know where we are going. And that is a big success."
With 20 years of experience as project manager, GS knows that the "human factor" is crucial for any project. "Managing people doesn't work by dictating what to think or do," he says. "It only works through belief and trust. You have to make people believe in what they are doing. For ITER, that means that you have to make the scientists understand that ITER—at the moment—is a construction project and that you can't do both at the same time: build and do continuous improvement by doing research. I know what I am talking about as I have worked on both sides."
He compares his role as Chairman of the MAC to being a navigator. "In a big international project like ITER each party has its legitimate concerns and differing opinions. This is very normal. The challenge here is to come up with a decision that is supported by all through faith and trust. Just compromise would not work," says Lee.
Before returning to Almaty, the Kazakh capital, the six-member delegation headed by Kazatomprom Chairman and former Energy Minister Vladimir Shkolnik, stopped in Cadarache and toured CEA installations and the ITER platform. Formal interaction between ITER and Kazakhstan in view of a possible accession to the project began after the third ITER Council, in June 2008.
Kazatomprom was established in 1997. It employs 25,000 people in uranium mining, nuclear pellets manufacturing, beryllium and tantalum metallurgy. The company is presently engaged in dismantling the 135 megawatt BN-350 installation, the world's first commercial fast breeder reactor that began operation in 1973 and was shut down in 1999.
Regions are the most recent among French administrative divisions. They were created in 1972 as consultative bodies, and only acquired limited executive power through the 1982-1983 "decentralization laws." They have much less autonomy however than a German Bundesland, a Spanish provincia or a Swiss canton.
Typically, a mainland French Region includes two to eight départements, with territory that usually corresponds to that of a historical province. There are many exceptions however. The Provence-Alpes-Côte-d'Azur (PACA) region, for instance, includes the whole of the ancient county of Provence, but also the former Papal States, county of Nice and the southern part of the Dauphiné province.
A region does not have authority over the départements it includes within its boundaries—the responsibilities of the two bodies are quite distinct. Roads, school transportation, public assistance, and the building and maintenance of collèges (junior high schools) all fall under the jurisdiction of départements; professional training, transportation, the building and maintenance of lycées (senior high schools), rural planning and development are among the responsibilities of the Région. The Bouches-du-Rhône département, for instance, finances the better part of the ITER Itinerary, whereas the construction of the International School in Manosque, which comprises a lycée, was the work of the PACA Region.
PACA is one of the largest and most populated French administrative regions (4.8 million inhabitants). With a Gross Domestic Product per capita of EUR 28,000, it is also the third "richest," after the Ile-de France (Paris) and Rhône-Alpes (Lyon) regions. PACA, which may soon change its name to a simpler "Provence," is headed since 1998 by Michel Vauzelle, a former Minister of Justice (1992-1993) and Mayor of Arles (1995-1998).
How does the PACA region work?