The latest major review of tokamak physics R&D in support of ITER was hosted by the ITER Organization during 12-14 December. The joint meeting of the International Tokamak Physics Activity (ITPA
) Coordinating Committee and representatives of the International Energy Agency's (IEA) Implementing Agreement for Cooperation on Tokamak Programs also marked the tenth anniversary
of ITPA's establishment .
In his opening remarks, the ITPA Coordinating Committee chair, Dr Yutaka Kamada of JAEA, noted that the ITPA directly involves 305 fusion experts from 65 institutes, together with a much larger group of collaborators who contribute to the ITPA's wide-ranging research on fusion physics.
The ITPA has built up a strong collaboration with the IEA's Implementing Agreements (IAs) on tokamak fusion research. The first joint meeting of the ITPA and the IEA IAs took place at MIT in November 2002 with the aim of developing a program of joint experiments on burning plasma physics which would strengthen collaboration among the world's major tokamak fusion facilities.Since that initial meeting, proposals for research which leverage the benefits of executing essentially the same experiment on two, three or more of the major tokamaks of the ITPA partners have been reviewed and approved through a joint ITPA/IEA-IA review meeting which takes place annually.
Following the integration of several of the IEA Implementing Agreements into a single Implementing Agreement on Cooperation on Tokamak Programs (CTP) it was agreed that joining the ITPA CC and the ITPA/ CTP meetings into a single annual review of the ITPA Topical Groups' research activities and their proposals for joint experiments addressing ITER's physics R&D priorities would provide an effective forum for evaluating and planning the work of the ITER partners' leading tokamak facilities in support of ITER.
The overall focus of this week's meeting was the review of the progress made by ITPA Topical Groups
in addressing ITER key physics R&D priorities, including areas such as H-mode plasmas, ELM control, disruption mitigation, plasma operation with metallic plasma-facing components, development of ITER plasma scenarios, energetic particle physics and plasma measurement systems.
Impressive results were presented by the Topical Group Chairs underlining the quality of the experimental, modelling and theoretical research undertaken within the ITPA framework. Many aspects of these presentations reflected the benefits of the program of joint experiments conducted by the tokamak facilities in collaboration with the Topical Groups. Further proposals for joint experiments were reviewed in a dedicated session of the meeting.
The meeting had a further significance in that it marked a major change in the leadership of the Topical Groups (TG). TG Chairs who have led research activities over the past three-and-a-half years, and whose service to the ITPA typically spans the entire 10 years of its existence, were warmly thanked by Dr. Kamada for their leadership and contributions.
A new group of Chairs, many of whom have served as TG Deputy Chairs in recent years, will now assume office and take responsibility for coordinating the R&D activities of each TG over the next three years.
The Diagnostic Neutral Beam—one of ITER Tokamak's three neutral beams—is about to enjoy some time in the spotlight. Work begun in 2009 on the civil construction works of the Indian Test Facility in Ahmedabad is now completed: here, the Indian Domestic Agency will install a full-scale test bed for the qualification of all diagnostic neutral beam parameters before installation and operation in ITER.
ITER's neutral beam system will consist of two heating neutral beams (HNB) and a diagnostic neutral beam (DNB) that share the same negative ion source technology. The purpose of the diagnostic neutral beam is to determine the level of impurities (helium ash) and a variety of performance parameters such as ion temperature, particle density and velocity by sending a 100 keV probe beam into the ITER plasma.
Extensive R&D is underway to resolve the numerous technical challenges of these systems: for the heating neutral beams that are under European and Japanese procurement, the PRIMA
test facility in Padua, Italy will house a full-scale prototype of ITER's heating neutral beam injector (MITICA). Here, too, the development of the ITER ion source will be advanced in the SPIDER facility with Indian participation.
"A similar need for research and development applies to the diagnostic neutral beam, however a test facility with DNB-specific objectives was not available," explains Arun Chakraborty, leader and Project Manager for the DNB at the Indian Domestic Agency, which is responsible for procurement
. "ITER India assessed the need and agreed, in consultation with the ITER Organization, to the configuration of a facility for the full characterization of the diagnostic neutral beam."
The Indian Test Facility is a voluntary effort on neutral beam R&D. ITER India has committed to providing the 600m² facility (plus 400 m² for the high voltage power supplies), the beam line components (neutralizer, residual ion dump, calorimeter), the vessel and auxiliary systems, while the diagnostic neutral beam source for the test bed—the ion source plus accelerator—will be provided by the ITER Organization.
"This additional effort and additional resources allocated to the diagnostic neutral beam by ITER India are greatly appreciated," says Beatrix Schunke, senior technical officer at the ITER Organization and responsible on the ITER side for the DNB. "The specifications for the diagnostic neutral beam are highly demanding. The Indian Test Facility is a voluntary contribution that shows a great commitment to the success of the ITER DNB program."
Although ITER's heating and diagnostic neutral beam injectors were designed to share many mechanical engineering traits in order to limit the number of overall components, the DNB is not a perfect replica of the HNB. The DNB will operate at a higher level of current (60 A as opposed to 40 A) and the specifications for DNB beam optics—no more than 7 mrad of divergence along a trajectory of 20.67 metres—are also much more stringent.
"It's a challenge to get the ion optics right across a large distance," explains Beatrix. "As the beam leaves the accelerator, instead of staying parallel it tends to widen. With the longest transport length of any test bed, the Indian facility will be a unique testing ground for 'far field' optics."
Engineers at the Indian Test Facility will also characterize an alternative design of a distribution system for cesium—a metal used in all negative ion sources. Based on a long distribution tube, the system would allow for cesium-oven replacement without a vacuum break in the DNB system. "If we are successful, it would result in considerably less downtime for the neutral beam systems," says Arun.
The Indian Test Facility will replicate all aspects of ITER's diagnostic neutral beam except remote handling. The civil construction for the facility was completed in August 2011 and the foundations are now in place to receive the beam line. The Indian Domestic Agency is in the process of reviewing the technical specifications of the DNB components before turning to industry for the procurement of the diagnostic neutral beam components.
For ITER, European Domestic Agency F4E or ENGAGE staff with an office facing the platform, the spectacular show continued last week as specialists from the German company GS-Energy finalized the installation of the 120-ton pylon that will hold the power cables for ITER's four-hectare switchyard.
Over two days this week, the four pre-assembled "arms" of the pylon, of which the largest weigh 16 tons, were hoisted one by one to the frame and bolted by a team of eight specialists in "acrobatic works."
Assembling a pylon requires some five tons of individual bolts. Once each bolt is properly tightened, it is "clipped" by way of hammer and awl in order to prevent it from unscrewing.
The spectacular aerial ballet will continue in the coming weeks as 12 identical pylons are erected and assembled along the six kilometres that separate the ITER platform from the existing 400 kV power line.
Next week, workers will pass "pulling cables," which are much thinner and lighter than power cables, through the temporary pulleys that can be seen hanging from the pylons' arms. Once these pulling cables are in place for at least two pylons, they will be attached to the power cables. Powerful truck-mounted winches will pull the power cables into place and pulleys will then be replaced by glass insulators.
Each pylon will support two power cables, each consisting of three "phase cables", plus two "lightning protection" cables. All cables are four-centimetres in diameter and are made of an aluminium alloy that is lighter, and cheaper, than copper.
A true reflection of the ITER project, pylon assembly is an international operation: most of GS-Energy's acrobatic works specialists are Lithuanian and communicate with their foreman in German. When the acrobats are at the top of the tower, some 40 metres above ground, they rely on the foreman's French skills to formulate their needs to the crane operator...
Gabriel Marbach, who joined fusion research in the early1990s, retired on 1 December from his position as head of the CEA Cadarache-based Institute for Magnetic Fusion Research (IRFM). He is succeeded by Alain Bécoulet, a physicist trained at the prestigious Ecole Normale Supérieure who was recruited by CEA in 1987 when all French fusion labs were moved to Cadarache.
A fast-neutron reactor man, Marbach was involved in the early phases of the ITER project when the machine's cooling system closely resembled that of the sodium-cooled reactors France was developing at the time (the "First ITER," in 1998, was designed with a liquid lithium cooling system.)
Bécoulet, who defines himself as "a physicist with a strong taste for experimentation," worked for JET (2000-2001), where he led the Advanced Tokamak Physics Task Force and later organized the Integrated Tokamak Modelling Task Force
—an important stepping stone for the worldwide ITER collaboration. At IRFM, from 2004 until last week, he led the plasma heating and confinement division. He had been Marbach's deputy since 2010.
Both men have had ITER on their horizon for the past thirty years and both worked hard to make ITER happen ... from just the other side of the fence.
On the occasion of the passing of the torch at IRFM, they reflected on their experience in fusion and on the ongoing relationship between fusion labs throughout the world and the ITER project.
Marbach and Bécoulet are among those who "raised" the ITER project almost from infancy. Even in the most difficult moments—and there were many—their faith never wavered. "We always believed in ITER but we knew it would take time," says Marbach. "The main challenge was to agree on the technological compromises that would make the cost acceptable. This explains the long and slow development of the project."
When the ITER site was finally chosen, the ITER Organization established, and work launched on the Cadarache site, both men confide that they felt "like parents who watch their grown children leave home and live their own lives"—proud, of course, "but with a slight tinge of sadness."
Now that ITER is living an independent life, parental guidance has graduated to "collaboration" and "partnership." And what is true of IRFM is also true for dozens of other fusion labs throughout the world.
The relationship between fusion labs, and on a more personal level between fusion scientists, has always been very strong. What has changed in recent years, Marbach and Bécoulet both note, is the outlook: "Research and development used to be machine-oriented. Now it is competence-oriented. This is something we owe to ITER: individual installations must now become tools for the whole fusion community."
Installing "ITER technology" on other fusion machines, such as the ITER-like wall at JET or a tungsten divertor at Tore Supra (the proposed WEST project) aims precisely at that. "I made sure that ITER became our priority," says Gabriel Marbach of his time at IRFM. "There are many things we can test and demonstrate at IRFM before the ITER machine enters its operation phase," adds Bécoulet. "We will save time for ITER, which means we can contribute to saving a lot of ITER's money ..."
What Marbach and his predecessors initiated, Bécoulet will continue. ITER however, is not the only item on his agenda. "ITER is a scientific tool," he says. "It's like a satellite: launching the satellite successfully is, of course, essential. But what matters more are the observations it will make, the data it will collect."
This precious data collected at ITER from realms that have not yet been explored will form the basis of fusion development in the 21st century. Both Marbach, who will keep an office at IRFM, and Bécoulet who now runs the Institute, are determined to keep their team in the race, ready for ITER and beyond.
The ITER Organization and the University of Science and Technology of China (USTC) have signed a Memorandum of Understanding "to promote cooperation and exchange in all academic and scientific fields of mutual interest and to advance the training of young fusion researchers." As one of the top-ranking universities in China, USTC encompasses an extensive range of disciplines and experts in various fields of relevance to the development of fusion power.
The parties agreed on establishing an ITER Training Forum at the School of Nuclear Science and Technology (SNST) which forms part of the USTC. The ITER Organization is expected to send five to ten experts each year to SNST to provide a series of lectures which will be presented over a period of one week. Each lecture series is intended to be in line with the domestic education programs. Young scientists, engineers and project managers from the international fusion program will be encouraged to participate.
The first ITER Training Forum will provide an overview of the ITER project and will, in addition, focus on various technical and physical topics ranging from ITER operation, to the deuterium-tritium fuel cycle system design, to IDM.
In addition, the ITER Organization may accept up to ten senior doctoral students or postdoctoral researchers chosen by SNST and approved by the ITER Organization each academic year in compliance with the ITER Internship Program Policy. The students and postdoctoral researchers will gain experience through working with the ITER Organization experts and participating in the daily activities of the host unit. They also will receive practical training in exploiting their skills by analyzing and solving specific problems under the guidance of ITER Organization supervisors.
The initial duration of the internship at the ITER Organization will be 12 months with a possibility of extension for a further period of up to 12 months.
For more information on the program, please contact David.email@example.com.
About 600 industrialists from more than 20 countries made their way to Manosque last week to participate in the ITER Business Forum. Organized for the second time since the inauguration of project, the two-day event was a useful platform for representatives of industry to meet ITER management and technical responsible officers and to discuss issues such as the design status of ITER components and the strategy for their procurement.
"The Business Forum is a necessary event in order to inform and involve industry at an early stage," stated the Director of Agence ITER France Jérôme Paméla in his opening address. "Without industry, there would be no ITER project."
In his status report on the project, ITER Deputy Director-General Rich Hawryluk, head of the Department for Administration, also highlighted the importance of exchange with industry: "It is great to have an idea on paper, but only industry can make it become reality."
In her long career as an astrophysicist, Catherine Cesarsky
, the French High Commissioner for Atomic Energy since 2009, has observed millions of fusion furnaces. Fusion in the Universe has been her jurisdiction for the past 40 years, first in Argentina where she was raised and received her initial training, then at Harvard and CalTech, and from 1974 to 1985 as part (and eventually head) of CEA's astrophysics department.
On Wednesday 7 December another kind of fusion—fusion on Earth—was the subject of Mrs. Cesarsky's visit to the ITER construction site and the CEA-Euratom tokamak Tore Supra.
Observing fusion on Earth does not require the use of a giant telescope like those of the European Southern Observatory
, which Mrs. Cesarsky headed from 1999 to 2007. Fusion on Earth—or at least the promise of—can be observed with the naked eye, from a bus window, and the view is almost as impressive ...