Propping and formwork on both slab and mockup

Take in the view and enjoy it while you can. In a couple months, the spectacular pattern formed by the 493 columns in the Tokamak Complex Seismic Pit — the emblematic image of ITER construction — will have vanished from view.

The lone scaffolding that was erected two weeks ago at the centre of the pit has already been joined by dozens of others. „Everything will be covered,” says ITER Nuclear Buildings Section Leader Laurent Patisson. Once the structures are in place, a steel rebar skeleton will be installed on top of them and pouring of the 1.5 metre-thick B2 slab will begin plot by plot (or "pour by pour") —a process which should take about nine months.

„The propping and formwork structures will support the weight of the rebar and concrete until the hardening of the concrete makes it possible to transfer the effort onto the seismic pads,” adds Laurent. „A total of 15,000 m3 of concrete will be poured, which—added  to the weight of the rebar (~ 4,000 tons)—will amount to a load of some 37,500 tons.”

Creating a reinforced slab over formwork structures that are supported by braced scaffoldings is a common technique. The very same process was implemented, two years ago, on the nuclear research reactor Jules-Horowitz (RJH) that is being constructed at CEA-Cadarache.

Every installation has its own geometry, however, which is reflected in the complex pattern of the steel reinforcement bars. „We have to demonstrate constructability prior to pouring the actual slab,” explains Laurent. „We also have to qualify the concrete and test the efficiency of the vibration techniques.”

To that effect, a 150 m2 mockup has been created on the platform to the west of the Seismic Pit. „Although 3D models of the rebar arrangements have been produced, we need a hands-on experience of the difficulties we may encounter.” Four different areas of rebar, presenting specific challenges (density, complexity), will be reproduced at 1:1 scale in the mockup. Work on the mockup began last week.

The mockup will also allow the practice installation and testing of the anchor plates that will be embedded into the concrete. These thick steel plates of various sizes, all dotted with long spikes (see picture), will reach deep into the concrete.

Once embedded into the concrete mass, the plates form an exceptionally solid base onto which equipment such as magnet feeders, drain tanks or cubicles can be welded. The Tokamak Complex will contain some 60,000 such plates.

„What is at stake beyond the B2 slab,” summarizes Laurent, „is the robustness of the whole Tokamak support, from the cryostat bearing down to the ground.”

Work progressed steadily last week on propping operations inside the Tokamak Pit and on its smaller mockup sibling nearby.

Team work celebrated at last Conductors Meeting

In pre-ITER times, the world production of niobium-tin (Nb3Sn) strands did not exceed 15 tons per year. Discovered in 1954, this intermetallic compound that exhibits a critical temperature of ~18 K and is able to withstand intense magnetic fields was used mainly in high field coils and nuclear magnetic resonance equipment.

To match the needs of ITER’s 19 toroidal field coils (18 plus one spare), the world production capacity of Nb3Sn strand had to be ramped up by one order of magnitude. As of today, 400 tons of Nb3Sn have been produced by the industry of the six ITER Domestic Agencies involved in conductor procurement, representing 85 percent of toroidal field coil needs.

Nb3Sn conductors will also form the core of the central solenoid, the backbone of the ITER magnet system. Strand production has been launched in Japan for the lower module (CS3L) and conductor lengths will be shipped at a later time to the US where the central solenoid will be manufactured.

For ITER’s third major magnet system—the poloidal field coils—because the magnetic field they produce is less intense, they can be manufactured from the metallic alloy niobium-titanium (NbTi), which is cheaper and easier to produce than the brittle Nb3Sn.

The Russian-European collaboration that procures NbTi strands for ITER has already produced 80 tons of Strand 1, destined for poloidal field 1 and 6. China, responsible for the procurement of conductors for poloidal field coils 2 to 5, has registered nearly 50 tons of of NbTi Strand 2 into the Conductor Database (this essential tool monitors the strand, cable, jacket and conductor production of each Domestic Agency). China will send its first poloidal field conductor shipment to the ITER site within the next two months.

Altogether, conductors for the magnet systems account for 13 percent of the total ITER project credits.

_To_45_Tx_These figures and other information relating to correction coils, feeder conductors, manufacturing issues, quality control, test results and technical issues were presented and discussed at last week’s meeting on conductor production status at the Château de Cadarache.

The Conductor Meeting, which has been held twice a year since 2008 (at ITER in the spring and in one of the „Conductor Domestic Agencies” in the fall), gathers representatives of the ITER Organization, the Domestic Agencies and their suppliers.

„It is an opportunity to share and benefit from each other’s experience,” says ITER Superconductor Systems and Auxiliaries Section Leader Arnaud Devred who traditionally chairs the meeting. „As all conductors are now in the production phase, the feeling in our community is definitely optimistic. Everything is moving ahead and the collaborative spirit, not only between the ITER Organization and the Domestic Agencies but between the Domestic Agencies themselves, is truly excellent.”

Management Advisory Committee meets in Barcelona

For the second time in its history, the ITER Council Management Advisory Committee (MAC) convened for an extraordinary session in order to assess the status of the ITER project schedule and the implementation of corrective actions.

The meeting took place from 18-19 March at the headquarters of the European Domestic Agency in Barcelona in the attendance of high-level representatives of the ITER Organization and seven ITER Members.

Since the last special MAC meeting held in August 2012, the ITER Organization has worked closely with Domestic Agencies to complete the integration of Detailed Work Schedules (DWS)—detailed schedules that exist for every component or system. The IO and DAs completed the integration of the remaining DWS, namely Main Vacuum Vessel, IC Antenna, PF Coils and TF Structure, which will allow for monitoring of the schedule.

MAC requested that the Unique ITER Team continue to make significant efforts to take action focusing on super-critical milestones and to take all possible measures to keep to the Baseline schedule. The ITER Organization and Domestic Agencies are committed to doing their best to implement this request.

To do business with ITER, Toulon was the place to be

Panjawani Rajkumar, the vice president of cryogenic system specialist INOX CVA, came all the way to Toulon, France from Vadodara in the Indian state of Gujarat. His company is in the process of bidding for an ITER contract and what he was looking for last week, at the ITER Business Forum, was a partner company, or companies, to complement his tender offer.

If INOX CVA wins the contract it will need to team up with a company that will install its workshop on, or close to, the ITER platform. It will also need a partner to enforce quality control and on-site safety. „If we get the contract, we will be working under French regulation. Rather than training Indian personnel, it is more efficient to have a partnership with a French company that is familiar with national practices and regulation.”

Panjawani Rajkumar was one of 718 participants (from 386 companies, universities or research institutions) from 24 countries that attended the third ITER Business Forum held on 21-22 March in the Mediterranean port of Toulon.

As in Nice in 2007 and in Manosque two and a half years ago, the ITER Business Forum (IBF) in Toulon aimed at providing international industry with updated information on the status of ITER, the procurement process, and the calls for tender planned for the coming years.

The third edition of IBF was organized by the Industrial Liaison Officers Network of the European Domestic Agency for ITER (Fusion for Energy), the Toulon Tourist Office, and the Chamber of Commerce and Industry of the Var département, with participation and support from the ITER Organization, Fusion for Energy and Agence Iter France. Representatives of the ITER Domestic Agencies were also present.

For anyone interested in doing business with ITER, IBF was definitely the place to be. In his welcoming address, ITER Director-General Osamu Motojima summarized what could be expected from the two-day meeting: „You will have opportunities, both formal and informal, to meet with representatives of the ITER Organization, Fusion for Energy and other institutions involved in ITER,” he told participants.

„These representatives will provide you with a better understanding of our project, of the machine we are building and of the procedures we are implementing. This meeting will also be an opportunity, for you, to develop collaborations, combine skills and create synergies that will benefit us all.”

Fusion for Energy Director Henrik Bindslev, who also addressed the IBF participants, stressed the importance for Europe to „increase competences and capacities […] in fusion and outside fusion. We want you to find opportunities in fusion and in ITER. That is what this Forum is about.”

And that is exactly what the IBF participants did. As Panjawani Rajkumar met with representatives of French companies, Pierre Janotton, an engineer with Belgium’s Centre Spatial de Liège—one of the world-leading institutes for space technology research and testing—was connecting with potential partners in the field of cryogenics, surface treatment and optics.

„You can draw several parallels between the conditions in space and the conditions in the ITER machine,” says Janotton. „We have a long experience in space and we made a first incursion into fusion recently by providing equipment to test the JT-60SA superconducting magnets. Of course we would like to have contracts with ITER and add our little stone to the project edifice, and this is the place to get the information and find the partners.”

Like Rajkumar and Janotton, the 718 participants in IBF left Toulon with dozens of contacts and several prospective partnerships. They brought home a better understanding of what ITER is about and a clearer perspective of the project’s economic weight. The local daily Var Matin summed it up in its Friday morning headline: „ITER: a four-billion-euro market for industry.”

ITER assembly: making plans today

When the starter pistol goes off for ITER assembly in the third quarter of 2014, a long and coordinated schedule of first-phase assembly activities will be set into motion—a schedule that begins with the installation of buried water pipes for the cooling water system and ends with First Plasma.

For the Tokamak alone, the schedule currently contains 40,000 lines.

The ITER Organization has the overall responsibility for all on-site assembly and installation activities, as well as testing and commissioning. „And not only for the ITER machine,” emphasizes Ken Blackler, head of the Assembly & Operation Division, „but also for the site-wide installation of plant systems in 37 buildings, such as radio frequency heating, fuel cycle, cooling water and high voltage electrical systems—this is often not realized.”

The Division’s role will be one of engineering, planning and management—the assembly work itself will be done by industry. The team is working now on the specifications for a large number of mechanical, electrical and other construction contracts. The workforce reunited through these contracts will represent between 2,000 and 3,000 people.

„The major question for us today is: What must we be doing now to prepare for assembly?” says Ken. „We are still in the 'paper phase’ this year; this is extremely critical in terms of schedule. The amount of preparation we do ahead of the game will guarantee that the real work will go well. What we do now, and how well we prepare, governs the future.”

To manage the organization behind ITER assembly, the biggest challenge according to Ken, the team has divided the site into six „chunks,” each one a separate assembly and commissioning project (the Tokamak is one project, for example; the high voltage power supply systems another…).

Line-by-line assembly procedures already exist for each critical ITER system or component—these are in the process of undergoing review by engineers from industry who are specialized in installation works: their role is to verify interfaces and ask the hard questions. Has enough space been reserved for the necessary tooling? Is there a „clear-and-free” assembly path? Can the requested tolerances be physically achieved? Will we be able to inspect, maintain, and eventually replace the components?

„Before assembly begins, our 40,000-line schedule for the Tokamak will be broken down even further by the construction contractor into a step-by-step instruction sheet—practically to the level of task-by-hour,” says Ken. „Plans at that level of detail will be needed for each one of our assembly projects.”

The assembly plan for each system or component is supported by a dedicated team comprised of Responsible Officers (ROs) from the Domestic Agencies, industry representatives and—from within ITER—ROs, contract managers, schedulers, and a cost controllers. When assembly begins, experts from the Domestic Agencies—where manufacturing has taken place—will be present on site. „If issues arise, as I’m sure they will, work stoppages could result which would cost money. So we will need to have the right experts on site with us capable of making fast decisions and solving these issues quickly.”

The Division will work closely with industry during assembly. ITER has experts in Tokamak assembly, while industry will bring construction experience. Ken already foresees early morning meetings to review daily work plans. The current assembly plan is based on two full work shifts per day, with the night shift reserved for testing operations or preparation of the next day’s activities (fetching components from storage, for example). A five-day work week during the assembly phase will be the norm according to Ken, but for some critical areas a sixth day will be necessary to adhere to the schedule.

Since arriving at ITER in 2008 to create the Assembly & Operations Division, Ken has built a strong team. „We have people who were involved in building and commissioning tokamaks like JET (EU), KSTAR (Korea) and the Indian machine SST-1, as well as CERN LHC, large telescopes and synchrotrons. But we also have engineers with nuclear, oil and chemical industrial experience that will be precious in a construction project like ITER.”

„The complexity of ITER assembly is related to the number of projects, the number of systems, and number of actors involved,” says Ken. „It is our job to reconcile all of that into a plan that will work.”

The Sun never sets on the CODAC empire

Every year in February, when almond trees begin to bloom in Provence, the ITER CODAC team releases a new version of the CODAC Core System.

The 2013 edition (CODAC Core System v 4.0) is more robust, comes with a better operator interface, offers more features, and supports plant systems that need „fast control,” for example plasma control systems that have to react within a strictly defined period of time. „Version 3.0 did it okay,” says ITER Control System Division Head Anders Wallander. „Version 4.0 does it better.”

CODAC (Control, Data Access and Communication) can be described as a software conductor that orchestrates the dialogue between the hundred-odd ITER plant systems …”the system of systems that makes one entity of everything” … the lingua franca that allows the magnets, blanket, tritium plant, cryostat and diagnostics to exchange signals and share information.

Working for the ITER project here and abroad, 55 organizations (Domestic Agencies, fusion labs, contractors) are presently using the CODAC Core System. An infrastructure has been set up to distribute the software to these and future organizations and to keep track of versions used. Training and user support is also provided.

The software package has recently demonstrated its efficiency on the Korean tokamak KSTAR and celebrated its „First Plasma,” so to speak, last June at the Frascati Tokamak Upgrade (FTU) project in Italy.  „The ITER CODAC system is truly becoming a world language,” says Anders.

CODAC is already implemented and deployed to monitor the power consumption on the ITER site, providing the „power people” with a global view and data with which to charge the different contractors operating on site. „With these pilot applications, we’re demonstrating that the system meets our expectations,” says CODAC System Engineer Franck Di Maio. „We’re demonstrating the system’s credibility.”

_To_44_Tx_CODAC users throughout the world are no different from any personal software user: switching to an upgrade is both exciting and challenging. „Although we provide support for older versions, we want to convince companies to upgrade. And the way to do it is to provide new features and make the upgrade easy.” In Franck Di Maio’s v 4.0 User Manual, the list of changes, fixed bugs, and enhancements of all kinds occupy no less than six pages …

Optimizing, upgrading and adapting ITER CODAC is „a process that will never end,” says Anders. „There will always be new requirements—this is the main difference between an experimental facility and a power plant.”

A time to be hopeful

„Without denying the challenges,” states Kattalai Ramachandran Sriram, „it is a time to be hopeful.”

Sriram arrived on the day of his birthday, 25 February, to take over ITER’s Finance, Budget & Management Directorate. He comes from the offices of the Comptroller and Auditor General of India where—with the exception of a six-year secondment to the Information Technology (IT) Audit Office in the Gulf state of Oman—he spent twenty-five years (1987-2012) specializing in performance and IT auditing.

Trained in electronics and communication engineering, with a Master’s in Business Administration, he joined the Comptroller and Auditor General of India because of the „great scope” offered by a career in the civil services and an interest in improving public and financial accountability. Over the years he successfully passed certification in auditing IT systems, internal auditing, and cost and management auditing.

He fulfilled auditing missions in civil aviation, hydrocarbons and rural development, internalizing the three „e’s” of the performance auditor along the way: Is the organization achieving its objectives effectively, maximizing its outputs (given the inputs) efficiently and managing its finances economically? 

These „e’s” were applied by Sriram and his four-person team to the Management Assessment of the ITER Organization in 2011. Leading this team, he says, was an experience that he looks back on as a privilege—never before had he had the charge to conduct an assessment of such a large-scale international scientific organization. He interviewed over 50 ITER employees and became familiar with ITER’s organization and internal processes: „The goal,” he says, „was to meet with a member of every division, section and sub-section.”

On the challenge of ITER’s in-kind procurement, the system by which ITER Members are all involved with the manufacturing of ITER components—in some cases exactly the same components—Sriram remarks: „For the ITER project, in-kind procurement is a challenge. Not a problem, not an issue, but a challenge.”

From the beginning, he explains, ITER was established as a scientific collaboration. „It was perfectly legitimate for all participating Members to wish to build up their own scientific and industrial capacities.” The challenge for the ITER Organization and the Domestic Agencies now, he says, is to ensure commonality of interests. He’s seen one very positive change since the Assessment—the Unique ITER Team established last year. „This is exactly the way to do things … a real improvement in processes.”

As head of Finance, Budget & Management, Sriram will be leading the Finance & Budget Division, the Project Information System Section (IT), and the System Management Section (SMS) … a very interesting „menu” of responsibilities. His 25-year career has left him well versed in financial management and IT—areas that interact extensively. And he sees great potential in the recent SMS group and its improvement program, which is already delivering value to the ITER Organization.

Sriram looks forward to the challenges and rewards of working in a multicultural environment. How can an organization integrate the best aspects of very diverse working styles and ensure that value is delivered? „Based on what I have seen and experienced, it is a time to be hopeful for the organization and the project.”

How to attract Russian specialists to mega science?

Participation in large-scale, unique international scientific and technical projects is among the most important orientations for Russia’s R&D potential today. Without a doubt, the specialists capable of solving the most demanding and sophisticated tasks in this type of project are a very valuable resource.

How to attract domestic specialists to this kind of project was discussed on 12 March at the Moscow Engineering and Physics Institute, (MEPhI) within the framework of a round table dedicated to the „Participation of Russian specialists in international megaprojects: fundamental research.” The round table was held by the magazine Atomic Expert and supported by the Strana Rosatom newspaper.

Important questions discussed during the round table were: How to develop a long term strategy for the participation of experts? Which resources and administrational solutions are required? On the efficient resolution of these issues depends the success of Russia’s collaboration in megaprojects, as well as the development of Russia’s fundamental R&D base.

The round table was moderated by Deputy Director of Rosatom’s Innovations Management Complex, Oleg Patarakin, and the Pro-rector for Research at MEPhI, Anatoly Petrovskiy. 

Anatoli Krasilnikov, head of the Russian Domestic Agency for ITER, presented a report on the human resource policy for the implementation of the ITER project. In his estimation, „the training of specialists for the implementation of the national program in fusion should be considered as one of the key tasks of Russia’s participation in ITER. We should work out and realize a rational system of staff training.” Oleg Patarakin also put an accent on the strategic importance of the ITER project. „ITER is a project of the highest world level, at the very core of science and technology. The project has long-lasting prospects, and specialists have the possibility of linking their professional lives to it.”
The round table participants shared the common opinion that attracting young people to megaprojects is a task requiring a complex approach that should be addressed by educational and research organizations, as well as legal bodies on different levels. For Russia, one of the main conditions of successful staff training is the development of long-term research programs.

For further information (in Russian) please follow the link:

Lawson’s magic formula

In 1955 a young engineer working on nuclear fusion decided to work out exactly how enormous the task of achieving fusion is. Although his colleagues were optimistic about their prospects, he wanted to prove it to himself. His name was John Lawson, and his findings—that the conditions for fusion power relied on three vital quantities—became the landmark Lawson Criteria.

The genesis of Lawson’s Criteria is simple enough—he calculated the requirements for more energy to be created than is put in, and came up with a dependence on three quantities: temperature (T), density (n) and confinement time (τ)*. With only small evolution thanks to some subtle changes of definition, this is basically the same figure of merit used by today’s fusion scientists, the triple product, nτT.

The amount of energy created relies on particles colliding and fusing—the number of collisions is related to the number of particles in a certain region—thus n, the number density (not mass density) is Lawson’s first criterion. This would seem encouraging for the prospective experiment, as creating high pressure is relatively easy. However there is a catch. At higher densities a process known as bremsstrahlung rears its ugly head, in which collisions between nuclei and electrons generate radiation. Bremsstrahlung can become so dominant that all the power in the plasma is radiated away; the optimum density conditions are surprisingly low, around a million times less dense than air.

Nonetheless the fusion collisions—between the nuclei—have to be at high speed. This allows the nuclei to overcome their electrostatic repulsion, and get close enough for the strong force that governs fusion to take over and stick the particles together. The speed of a gas or plasma particle is equivalent to its temperature: the second of Lawson’s criteria.

Again there is a limit—if the two particles are moving really fast then the time they are in close enough proximity for fusion to occur decreases. The bremsstrahlung also increases at higher temperatures, due to faster moving electrons. The Goldilocks temperature turns out to be in the vicinity of 100—200 million degrees, a seemingly huge task in the fifties that has become a standard condition today.

* "τ" is the Greek letter tau (pronounced like "how").

Read more on the EFDA website.

53 mayors who are also "partners"

There are more municipalities in France than in all of Europe combined.

Every village, however sparsely populated, is a municipality in its own right and every municipality follows the same procedure to elect its municipal council every six years: at its first meeting, the new municipal council elects the mayor, or „First Magistrate.”

Whatever the size of the constituency, madame or monsieur le maire is a major figure in the administrative organization of French society.

ITER was honoured, on Monday 11 March, to welcome no fewer than 53 mayors from neighbouring municipalities—from the smallest (Valavoire, pop. 32) to the largest (Sisteron, pop. 7,500).

Led by Daniel Spagnou, mayor of Sisteron and president of the Association of Mayors of the Alpes-de-Haute-Provence département, the 53 mayors were given a presentation on ITER by Director-General Osamu Motojima and a quick round-up by Agence Iter France director Jerôme Paméla.

„You are our partners in this scientific venture,” DG Motojima told the mayors. „Once ITER has demonstrated the technical and scientific feasibility of fusion energy it will be your responsibility, as representatives of the people, to decide on the next steps that will be taken.”

Monday 11 March was the second anniversary of the Great East Japan earthquake, tsunami, and resulting nuclear accident at Fukushima—Director-General Motojima insisted during his talk on the fundamental differences between fusion and fission in terms of safety. „A Fukushima-like accident cannot happen in a fusion installation,” he stressed.

In 2003, the Alpes-de-Haute-Provence département (pop. 160,000) pledged EUR 10 million to the ITER project. It turned out to be a sound investment: to date, companies based in the département have benefitted from contracts amounting to EUR 29 million.

Hot, hotter, hottest

Temperature, from a physicist’s perspective, is not only a measure of hot or cold.

It is also a measure of the energy carried by atoms and molecules: temperature tells us how rapidly these atoms or molecules move within a solid, a liquid or a gas.

Temperature is different from heat. To feel heat on your fingers, you need density: the higher the density, the more heat is transferred to your skin—this explains why a neon tube containing a very hot (~10,000°C) but very tenuous plasma can be touched without harm.

In temperature, there is a theoretical absolute cold („absolute zero”) but no absolute hot: a particle can always move more rapidly but it cannot be more immobile than … immobile.

When we talk about a 150- to 300-million-degree plasma in ITER, we’re describing an environment where particles (the deuterium and tritium ions and the freed electrons) move around at tremendous speed: so fast and with such a high energy that when they collide head on the miracle of fusion happens. The electromagnetic barrier that stands between nuclei is overcome and the nuclei can fuse.

How will the ITER plasma be brought to such extreme temperatures—ten times higher, or more, than the core of the Sun?

Plasma heating in ITER will begin with an electrical breakdown, quite similar to what happens when we turn on the switch of a neon light. In the very tenuous gas mixture that fills the vacuum vessel (one million times denser than the air we breathe) the electrical discharge strips the electrons from the atoms and the gas becomes a plasma—a particle soup of electrically charged electrons and ions.

„The electrons from the current collide with and communicate their energy to the ions from which they have been stripped,” explains Paul Thomas, ITER Deputy Director-General for CODAC, Heating & Diagnostics. „Current intensity grows steadily and, as plasma resistance increases due to the collisions between electrons and ions, temperature also rises—this is Ohmic heating, like in a bread toaster or an electrical radiator.”

However, contrary to what happens in metals, plasmas have an unusual property in terms of resistivity: the hotter they get, the less resistive they become. This means that Ohmic heating can heat a plasma only up to a point.

„For a long time,” Paul recalls, „some fusion physicists dreamed they would achieve fusion with Ohmic heating alone by increasing the magnetic field. Even today, the project called Ignitor is based on this assumption. The problem is that the more intense the magnetic field, the stronger the mechanical strain on the machine’s structure…”

Ohmic was the only heating source on the Soviet T-3, which achieved plasma temperatures in the range of 10 million degrees in the late 1960s—an achievement that left the nascent world fusion community agog and launched the tokamak race worldwide.

Achieving fusion, however, requires temperatures approximately ten times higher than what Ohmic heating alone can provide. In the 1970s, the fusion community began experimenting with additional heating techniques based on radio frequency (RF) waves, or the injection of energetic atoms into the plasma.

Yes, radio waves can heat. Whether at 40-55 MHz, like shortwave radio (ion cyclotron; a few GHz like microwave ovens (lower hybrid) or many tens to hundreds of GHz like very advanced radar (electron cyclotron), sending electromagnetic into the plasma can deliver enough energy to push it into the fusion regime. ITER will be equipped with an electron cyclotron and an ion cyclotron heating system, both delivering 20 MW of power.

But the workhorse of additional heating in tokamaks has been neutral beam heating—the injection of high-energy neutralized particles deep into the plasma.

Neutral beam heating is a bit like heating the milk in a pot by using a jet of hot steam from the espresso machine, what French garçons de café systematically do when you order cappuccino. As hot molecules from the steam jet collide with those of the cold milk, energy is transferred and hot milk is ready to be poured in the coffee cup.

„Exploitation of the neutral beam technologies we will use was pioneered in Japan,” says Paul. We have a very strong collaboration with our friends in Naka. Neutral beam technology is also used on JET (ITER’s neutral beam system will deliver seven times the energy of JET’s).

The challenging technology of ITER’s neutral beam system will be tested in a dedicated installation that was inaugurated a year ago almost to the day: the PRIMA Neutral Beam Test Facility in Padua, Italy. In parallel, IPP Garching is developing ELISE, an ion source half the size of ITER’s; success on this test bed will greatly reduce the risk associated with the final development of the full-size ITER ion source at the SPIDER test facility.

ITER’s three heating systems—electron cyclotron, ion cyclotron and neutral beam—feature different levels of technical complexity, maintainability and ease or convenience of use. The balance between these features is such that all three should be tested on ITER and developed to the point where a decision can be taken on which should heat a reactor, according to Paul.

„The reason we’ll have all three systems in ITER is to have them compete in the nuclear environment — this is precisely what the 'technological viability’ demonstration is about.”

Korea awards contract for ITER thermal shields

The Korean Domestic Agency signed a contract with SFA Engineering Corp. for ITER thermal shields on 28 February. The contract covers the detailed design of manifolds/instrumentation, the manufacturing design and the fabrication of the thermal shield system. „For us, this is a big step forward for the Korean contribution to ITER,” said Myeun Kwon, president of the National Fusion Research Institute, after the signing.

SFA is a leading company in industrial automation with much experience in the procurement of advanced equipment related to fusion, accelerator, and space technology. SFA was deeply involved in the manufacturing and assembly of the Korean tokamak KSTAR.

The ITER thermal shield will be installed between the magnets and the vacuum vessel/cryostat in order to shield the magnets from radiation. The thermal shield consists of stainless steel panels with a low emissivity surface (<0.05) that are actively cooled by helium gas, which flows inside the cooling tube welded on the panel surface. The temperature of helium gas is between 80 K and 100 K during plasma operation. The total surface area of the thermal shield is approximately 4000 m2 and its assembled body (25 m tall) weighs about 900 tons.

The key challenges for thermal shield manufacturing are tight tolerances, precision welding, and the silver coating of the large structure. The thermal shield also has many interfaces with other tokamak components. „The Korean Domestic Agency is satisfied with this contract because the thermal shield is one of the most critical procurement items in the ITER project. We will do our best in collaboration with the ITER Organization to successfully procure the ITER thermal shield,” said Hyeon Gon Lee, DDG of the Korean Domestic Agency, on the occasion of the contract signature.

Tore Supra components to start new life in China

Surprisingly, some twenty years of sporadic exposure to a temperature of 60 million degrees have left little trace on the C2 antenna’s „mouth” — except for a bit of superficial melting here and some black deposits there, Tore Supra’s lower hybrid antenna looks almost as new as the day it was installed.

One of the two original lower hybrid antennas of the CEA-Euratom tokamak, C2 greatly contributed to the progress of current drive analysis. It also played a key part in the success of the machine. „It is the hybrid system that allows for long pulses,” explains Roland Magne, head of the Radio Frequency Heating and Current Drive group at CEA’s Research Institute on Magnetic Fusion (IRFM).

Tore Supra entered operations in 1988 at CEA-Cadarache and still holds the world record of discharge duration with a 6-and-a-half-minute pulse achieved in 2003.

As science and technology steadily progress, vital components in a research installation like Tore Supra must be replaced or upgraded; C2’s twin C1 was replaced in the early 1990s and C2 was permanently removed from the installation in 2008 in order to make room for the Passive Active Multijunction (PAM) antenna which was installed two years later. (The PAM is equipped with an integrated cooling system that allows it to deliver more power density to the plasma over longer periods of time.)

„C2 is still in good condition and can be advantageously re-used for current drive experiments on another machine,” adds Magne. Recycling has always been part of fusion history: last week, the C2 was being prepared for a long trip to China. The antenna will soon be fitted onto the Chinese tokamak HL-2M, currently under construction at the Center for Fusion Science of China’s Southwestern Institute of Physics (SWIP) in Chengdu.

C2 will not travel alone. Tore Supra is also shipping the 8 3.7 GHz, 500 kW klystrons that used to feed the antenna. Although they also operated for more than 20 years, the C2 klystrons (electron tubes that generate and/or amplify the radio-frequency waves) are still in operating condition.

The antenna and the klystrons will set the stage for a collaborative physics experiment between IRFM and SWIP. As a first step, four of the klystrons will be coupled to an antenna that the Chinese are designing for the existing tokamak HL-2A for experiments due to begin in 2014. (HL-2A is the original ASDEX Tokamak that was transferred from IPP Garching to China in 1995, and entered operations at SWIP in 2002.) When HL-2M is operational in 2015, all eight klystrons will be connected to the C2 antenna.

„This collaboration will provide for some very important ITER-relevant physics program,” adds Magne.

On Tuesday, as the C2 antenna was about to be packed in its wooden crate, Chinese staff from CEA and ITER, all originally from SWIP, came to bid farewell. By 2015, both the antenna and the klystrons will start a new life in a brand-new tokamak on the other side of the world.

Close to 900 celebrate Japan Day

Close to 900 people—a record for the ITER canteen—attended Japan Day on Monday 4 March, the latest National Day celebration at the ITER Organization.

ITER’s celebration coincided with a Japanese tradition called Hinamatsuri, or Girls’ Festival, celebrated on 3 March—a day to pray for a young girl’s growth and happiness. In the weeks leading up to this festival, most families with girls display ornamental dolls representing the Emperor, Empress, attendants, and musicians in the traditional court dress of the Heian period, and arranged on a five- or seven-tiered stand covered with a red carpet.

At the luncheon attended by the Consul General of Japan in Marseille, Masaaki Sato, and his wife, traditional Japanese dishes were prepared by ITER’s Sodexo food service: kenchin soup and either an oyako or tamago rice bowl.

The ITER band accompanied singers Michiya Shimada, Sachiko Ishizaka, and Arata Nishimura from the ITER Organization and Masao Ishikawa (JAEA) in a selection of Japanese pop and folk tunes known in the West as „Sukiyaki” songs, that inspired some members of the assembly to join in.

Click here to view the Japan Day image gallery.

Fusion, with a touch of science fiction

An imposing object stands at the heart of the Tom Hunt Energy Hall in the recently opened Perot Museum of Nature and Science in Dallas, Texas.

The four-metre-high structure is a mock-up of the ITER Tokamak—or, rather, a designer’s „interpretation” of the science of fusion and of the flagship device of fusion research.

Those familiar with the arrangement of components that make up an actual tokamak—central solenoid, vacuum vessel, toroidal and poloidal field coils, divertor, piping and feeders—will be a bit lost when gazing upon the towering mockup.

This is intentional. „Our goal was to create a sense of wonder in our visitors that might inspire them to learn more about the subject,” explains Paul Bernhard, whose team designed and installed the 700-square-metre Tom Hunt Energy Hall. „We see our tokamak as based in science, but coloured by a future vision influenced by science fiction—a somewhat cinematic element that you might imagine seeing in a new Star Trek film…”

The result is indeed spectacular. Although Bernhard’s tokamak looks a bit like a thermonuclear mushroom cloud—a „purely coincidental” similarity due to the geometry of the large rounded shape containing the brightly glowing "plasma" suspended over the narrower central core—it is a truly astonishing work of science art.

The moment of awe passed, visitors can experiment with a neon/argon plasma, manipulating it with a magnet; have a hands-on experience with actual toroidal field coil and central solenoid conductor sections provided by the US Domestic Agency; or watch video clips.

Impressed by the „amazing potential of fusion energy,” Bernhard and his team sought to „pass along [their] sense of inspiration.” In stimulating curiosity and enthusiasm for the sciences, a bit of artistic license can’t do any harm.

Progress on ELM physics and ELM control

Fusion energy production in ITER requires the achievement of high pressure plasmas in high energy confinement mode (H-mode). This confinement mode is characterized by the formation of very steep plasma pressure profiles at the edge of the plasma that lead to periodic bursts of energy being expelled by the plasma (typically a small percentage of the total plasma energy) called ELMs (Edge Localized Modes).

Although ELMs have no impact for the vacuum vessel, due  to the large plasma energy of ITER plasmas the energy bursts caused by ELMs can lead to an accelerated erosion of the divertor and first wall components in contact with the plasma.

 This could lead to a more frequent replacement than foreseen in ITER. In addition, the eroded atoms can penetrate and contaminate the plasma thus decreasing the energy production.

ELM control is required for the achievement of fusion energy in ITER. Two schemes are foreseen to minimize the impact of ELMs—pellet injection and in-vessel ELM control coils.

Understanding the magnitude and structure of the ELM energy bursts and quantifying the effectiveness of ELM control schemes is an active field of research where significant progress has taken place recently. Simulations of ELMs in ITER with the non-linear code JOREK have shown that there are two mechanisms for the flow of energy from the plasma to the components in contact with the plasma during ELMs (see image above): one is the loss of energy by the plasma in the strongly perturbed edge magnetic field during the ELM (conductive losses); the other is the expulsion of plasma filaments (analogous to solar flares) which move radially away from the plasma towards the wall.

JOREK simulations show that for small ELM energy losses the dominant mechanism is the expulsion of filaments and that this energy is deposited over a large area of the divertor and wall. This allows more room for ELM control in ITER than originally anticipated.

Progress on ELM characterization and ELM control has also come from the experimental side. ELM avoidance using 3-D field magnetic field perturbations, which will be provided in ITER by a set of 27 in-vessel coils, has now been achieved in a large number of experimental devices. Results span the range of densities and collisionalities expected at the ITER plasma edge, although ITER values cannot be achieved for both parameters simultaneously (these can only be achieved in ITER itself). While understanding of the detailed physics processes that lead to the avoidance of ELMs with 3-D magnetic field perturbations remains elusive, ELM avoidance using this scheme has now been observed in numerous experimental devices. This increases our confidence in the viability of this ELM control scheme for ITER.

Recently, there have also been major advances on the second ELM control scheme foreseen for ITER, which utilizes the controlled triggering of the ELM bursts by the injection of small frozen deuterium pellets. Experiments in the DIII-D tokamak in which very small pellets were injected have demonstrated for the first time that this technique can be used to increase the frequency of the ELM bursts, and to decrease the magnitude of the fluxes that they deposit, by more than a factor of ten (a factor of 30 may be required in ITER). In these experiments, detrimental effects on the plasma energy confinement were modest. This is a major advance from previous results in JET, ASDEX-Upgrade and DIII-D, where factors of only 2-5 were achieved in ELM frequency, but, in some cases, with noticeable detrimental effects on plasma energy confinement.

The DIII-D experimental results have been reproduced with the JOREK code, which has subsequently been applied to evaluate the pellet characteristics (size and velocity of injection) required in ITER to achieve controlled triggering of ELMs (see image at left). The JOREK results show that these requirements are met with the specifications foreseen for the ITER pellet injection system and pellet injection geometry. The associated fuel reprocessing requirements are also consistent with the specifications of the ITER tritium reprocessing plant.

Although uncertainties remain regarding ELMs and the application of the ELM control schemes to ITER, recent progress in this area has substantially increased our confidence that ITER is equipped with the appropriate tools to achieve the ELM control level required for the achievement of significant fusion energy production.

From an ultralight’s perspective

The last time an aerial photo survey was conducted of the ITER site, in September 2011*, the lower basemat had yet to be poured in the Tokamak Seismic Pit; cladding and roofing operations were underway on the Poloidal Field Coils Winding Facility; and windows were being installed at ITER Headquarters.

A year and a half later, a four-hectare electrical switchyard is in place and 500 people work from the completed Headquarters building. Preparatory works have just begun for the Tokamak Complex basemat (the B2 slab) that will rest atop the Seismic Pit’s 493 concrete columns (plinths) and pads.

Whereas in 2011, vast expanses of barren land still existed between the different work areas on the platform, this new series of photographs, taken two weeks ago, shows a much different landscape: mounds of earth, trenches, and material and vehicle storage areas now occupy most of the available space between the buildings.

In the Seismic Pit, the radial pattern of the plinths is clearly visible from the air. Nearby, the completed sections of the Assembly Building foundation slab reflect the mid-afternoon winter sun. From the Headquarters Building, long shadows extend almost all the way to the deserted parking lot (the photograph was taken on a Saturday). On the „green” rooftops of the Access Control Building, the Amphitheatre and the Medical Building, the sedum plants wear their winter colour—they will turn from red to green in the summer and from green to yellow in the fall.

Photographer Matthieu Colin carried out the latest ITER aerial campaign from an ultralight aircraft flying at an altitude of 500-900 metres. (The September 2011 photographs had been taken from a helium-filled balloon hovering at 70-100 metres above ground.)

* The December 2012 pictures that appear in our web site’s photo Gallery were taken from a cellular radio tower 40-metre high.
Click here to view more aerial photographs of the ITER site.

Looking for "a model of engagement"

Fusion research is deeply indebted to Australia: it was the Australian Mark Oliphant who, under the guidance of Ernest Rutherford, realized the first fusion reaction at Cambridge’s Clarendon Laboratory in 1933, and it was in Australia where the only tokamaks outside the Soviet Union operated between 1964 and 1969.

Over the past half-century, the country’s small but active fusion community has developed a strong reputation, carrying out seminal theoretical work in plasma physics, developing significant plasma diagnostic innovations and making important contributions to fusion materials research.

Many Australian fusion physicists are closely associated to the ITER project. While Australia is not an official Member, these physicists are eager to see their country engage with it. As yet, no formal institutional collaboration has been established.

On his visit to ITER, last September, Australian National University physicist Matthew Hole, who chairs the Australian ITER Forum, shared his hopes for Australia to become more involved.  "ITER," he said, "will define the fusion research program for at least the next generation. We’re keen to be part of that enterprise …"

How could Australia be more closely associated to ITER? The question was at the centre of the „very useful conversations” that Adi Paterson, the Chief Executive Officer of the Australian Nuclear Science and Technology Organisation (ANSTO), had with the ITER management when he visited here on 20 February.

„A project the size and scope of ITER cannot be limited to only seven Members,” explains Paterson. „ITER has to think of countries like Australia that can connect to the project in a very effective manner outside of a full membership arrangement and potentially form a new model of engagement.”

In this context, ANSTO has an important role to play. „My job is to help define and implement a coherent strategy and assist in strengthening the fusion community at home” adds Paterson. „We need to initiate exchanges, develop knowledge on the real questions of diagnostics, 3D fields, energetic particles, collision cross-sections, materials, neutronics…”

The „model of engagement” doesn’t exist yet, but both sides are eager to create one. Seeing the reality of the project’s progress comforted Paterson in his determination. Along with the obvious progress of construction and of components manufacturing, what makes ITER real in the eye of ANSTO’s CEO is „the milestone that was accomplished last November. When the nuclear safety regulator says 'you can carry on’, this is a huge accolade, and one that brought confidence to the whole fusion community worldwide.”