It has been almost one year since the fabrication of the first ring coil was launched in the on-site Poloidal Field Coil Winding Facility by European Domestic Agency contractors. Out of the eight "double pancake" conductor windings needed to finalize the 350-tonne magnet, three have been wound and are ready to pass through the resin-impregnation phase—an operation that contributes to both electrical insulation and structural strength. On one of the circular platforms on the southern end of the silent, clean and temperature-controlled facility, a double pancake sits, still attached by 24 lifting points to the circular spreader beam that has just moved it from the stacking station.   A few metres away, technicians are busy assembling the vacuum containment vessel—the "mould"—that will enclose the double pancakes throughout the lengthy and delicate resin impregnation process.   "During impregnation, we inject some 600 litres of epoxy resin at a temperature of 55-60 °C through entry ports in the mould," explains Gian Battista Fachin of the European Domestic Agency, who works in the facility where Europe is fabricating the four largest ITER poloidal field coils. "At that temperature the resin is as liquid as water and easily penetrates through the fiberglass wrapping of the double pancake."   Once extra pressure has been applied inside the leak-tight mould to insure that all micro spaces are properly filled, the resin's temperature is ramped up first to 100 °C for a few hours of "gelling," then to 140 °C for a full day and a half of "curing." By then, the resin has become rock solid and the shining white double pancake has turned into a massive block the colour of caramel.   The resin impregnation process was tested and validated on a "dummy" conductor winding that is presently stored at the far end of the building.   "We learned a lot from the dummy, right from the beginning operations that began in November 2015," confirms Gian. "We established metrics and procedures, refined bending parameters, impregnation and injection durations ... everything a dummy is for."   The dummy is a perfect replica of an actual double pancake for the 17-metre-in-diameter poloidal field coil #5 (PF5). For reasons of cost however, it is wound from copper conductor rather than from superconducting niobium-titanium alloy.   Technicians are busy assembling the vacuum containment vessel—the "mould"—that will enclose the double pancakes throughout the lengthy and delicate resin impregnation process. When all eight double pancakes for PF5 are finalized (winding is underway on the fourth in the series now) they will be stacked to form a winding pack—the coil's very core—which will be wrapped with insulating fiberglass tape and impregnated with resin as one single component.   The winding pack will then receive additional equipment such as clamps, protection covers and pipes. At that point, one last crucial operation remains to be performed before the component can be considered fit for duty.   When ITER enters operation, liquid helium circulating inside the conductor will bring the coil temperature down to 4 K (minus 269 °C) to create the physical conditions for superconductivity in the niobium-titanium conductor.   Throughout the manufacturing process, sample tests and quality control have insured that the conductor's performance in such extreme conditions is in line with the magnet system's requirements.   What remains to be tested however, is the coil's behaviour as a whole. How is it affected by the thermal contractions generated by the ultra-cold temperature? Does the liquid helium circuit within the cable-in-conduit conductor remain leak-tight? Can cracks develop in the resin and hinder electrical insulation?   Resin-impregnation procedures were tested on this double pancake "dummy"—a perfect replica of the conductor, only made of copper instead of the superconducting niobium-titanium alloy. These questions can be answered without having to cool the coil all the way down to 4 K. At the temperature of liquid nitrogen (80 K or minus 193 °C) thermal contractions have already reached their maximum and all the potential issues can be identified. Also, cooling with liquid nitrogen is much cheaper and easier to implement than cooling with liquid helium.   In May, the cold testing equipment will arrive from Italy for installation in the northern end of the workshop. The four coils manufactured on site (ranging from 17 to 24 metres in diameter) will be tested one after the other in the cold testing vacuum vessel, as will a smaller coil (10 metres in diameter) that is being manufactured in China under an agreement with Europe.   Cold-testing operations are scheduled to begin in the summer of 2019 and last for more than one year.

Of all the features that have changed the most since the last bird's eye view of the ITER site in January, the bioshield is the most striking. For two years, the structure had remained open to the sky, looking more and more like Rome's Colosseum as it grew, with its circular shape and row upon row of large openings. That vision is now gone. The "lid" that had been installed at mid-height since September was recently lifted to the top of the structure, closing off the massive steel-and-concrete cylinder. We are no longer looking at the Roman Colosseum, but at something more reminiscent of Hadrian's mausoleum...   Other changes, observed from the highest crane on the site, are less spectacular but no less significant in terms of worksite progress. Please see the details in the gallery below.  

Good progress on the installation of the first of two specialized tools for vacuum vessel pre-assembly means that by late June, the 22-metre-tall giant will be ready for functional testing. Side-by-side in the Assembly Hall, the largest bespoke tools in the project's assembly toolkit will be active for approximately three years—from 2019 to 2021—smoothly opening and closing their lateral wings (millimetre by millimetre) to associate thermal shielding and a pair of toroidal field coils to each of the nine vacuum vessel sectors before their transfer to the Tokamak Pit for welding.   The three-footed tools will support the 440-tonne sectors vertically, as the components are positioned and aligned to millimetre-level assembly tolerances. Each unit—built from 800 tonnes of metal plus auxiliary components—is designed to support nearly 1,200 tonnes of dead weight.   A sophisticated system of actuators on the lower platforms will allow operators to control alignment to within one millimetre. A dummy load of 340 tonnes will be tested on the equipment early next year. The first tool, delivered to ITER in batches last year by the Korean Domestic Agency, is now nearly completely assembled, with all key components for the rails, rotating frames, rotating arms and inboard column in place. By the end of April the remaining equipment—lower alignment units and two outboard columns—will have been installed.   Functional tests are planned in June. The same month, the second sector sub-assembly tool—which completed factory acceptance tests at Taekyung Heavy Industries in Korea in March—will be delivered to ITER for assembly.   By next February, both tools will be ready for the final test before entering operation—verification with a full-weight dummy load of 340 tonnes, or the weight of one toroidal field coil plus a 10 percent safety margin. This final qualification activity will allow operators to verify the tools' ability to accurately adjust the dummy load toroidally and to six degrees of freedom* within tolerances of +/- 1 millimetre. *Six degrees of freedom refers to adjustability along X, Y and Z axes (up and down, side to side, forward and backward) as well as in rotational directions relative to the axes (swivel, tilt, pivot).

The first power supply units produced in Europe for ITER's microwave plasma heating system have successfully passed factory acceptance tests. In ITER, 12 high voltage power supplies will convert grid voltage to the high voltage levels required by ITER's electron cyclotron heating system (ECRH). Europe, which is responsible for the supply of eight of these, has contracted with the Swiss company Ampegon for the design and fabrication of the equipment. Ampegon will produce eight main high voltage power supplies (55 kV/110 A) and 16 body power supplies (35 kV/100 mA).   In March, the first main high voltage power supply and two of the body power supplies successfully passed factory acceptance tests.   The high voltage supply units are powerful indeed. The eight units alone could provide sufficient household electricity for a city of 270,000 inhabitants.   The electricity generated by these units will feed into the ECRH, which is one of three external heating systems that will bring the ITER plasma to temperatures allowing for fusion to occur. The 24 gyrotrons at the core of the ECRH system will generate strong electromagnetic waves—not unlike a powerful microwave oven—which will be guided to the vacuum chamber, where they transfer their energy to the plasma particles and heat them.   During the factory acceptance tests the power supply units exceeded expectations, according to Ferran Albajar, who is in charge of gyrotrons at the European Domestic Agency. The production of the remaining units will be completed in 2020. Please see the full report on the European Domestic Agency website.

With its external steel structure a deep blue; its poloidal field coils bright red and its waveguides sparkling yellow, Tore Supra (now WEST) has always been an exceptionally colourful tokamak. Last Friday, as WEST was being inaugurated, a spectacular light show added to its already rich palette.   Although it has been more than a year since it produced a first plasma, the rejuvenated, ITER-relevant machine officially came into the world last week. Two French Parliament members, several representatives of the local governments that contribute to the project's funding, and representatives of the Administrator-General of the French Alternative Energies and Atomic Energy Commission (CEA) hailed the "beautiful collective adventure" that has led to WEST's realization.   "Acting as a test-bed for ITER , WEST will mitigate the risks associated with an all-metal divertor," explained Alain Bécoulet, the head of CEA's fusion department.   Located at CEA Cadarache, a stone's throw away from ITER, the WEST project was launched in 2008 at a time when Bernard Bigot, the present ITER Director-General, headed CEA. In-kind procurements from China, Korea, Japan, India and Europe contribute to more than a third of WEST's EUR 24 million budget.   The WEST project and its research plan are open to the international fusion community. The WEST platform will be run as a user facility, open to all ITER partners.

Taiyô Tenno is a young Japanese student on a world tour of "art masterpieces"; Soléane is "a scientist at heart," presumably French, who speaks perfect Japanese. They meet at Cézanne's workshop in Aix-en-Provence and soon find themselves seated at the terrace of Les Deux Garçons, the town's most elegant café. Soléane speaks Japanese because her work in "energy research" implies a lot of "professional dealings with Japan." Taiyô Tenno is impressed, especially when Soléane explains that her work is about "duplicating the energy-generating process in the Sun and stars"... The first manga on ITER—"A small sun on Earth"—has just been published by ITER Japan and is available in Japanese, French and English. Visit this website to download the manga.

The International Zvenigorod Conference on Plasma Physics and Controlled Fusion is an annual rendezvous near Moscow for fusion research specialists from Russia and abroad. For one week in April, recent achievements in high and low temperature plasma research, the field of controlled fusion, and the development of plasma and beam technologies are presented through lectures, short talks and poster presentations. Russian participation in the ITER Project was reported at the "ITER Project: Step to future energy" portion of the program under the direction of Anatoly Krasilnikov, director of the Russian Domestic Agency. Representatives of the research centres and the industrial companies involved in the procurement of ITER systems and components were present to report on the challenging technical specifications of the packages under Russian responsibility and the benefits of participation in ITER for the Russian research infrastructure overall. More on the annual conference here. --ITER Russia