Plasma experiments at ITER will be driven by a complex real-time software infrastructure. This infrastructure will be developed with support from the fusion community in an open international collaboration, currently with partners from Europe and the US. The CODAC Section of the ITER Organization and the Max Planck Institute for Plasma Physics (IPP) in Garching, Germany, have agreed on a long-term collaboration to drive this development.   One of the major aims of the collaboration is also the deployment of the real-time infrastructure at the ASDEX Upgrade tokamak where it will be tested in routine operation. The migration of the real-time control system of ASDEX upgrade to the new infrastructure is foreseen, making it an ideal machine to develop and demonstrate control concepts for ITER using an identical software base.   Controlling the fusion plasma for ITER is a very complex task. It involves not only magnetically confining and stabilizing the plasma, but also driving the machine to achieve its performance goal of Q=10 and a produced fusion power of 500 MW.   "In order to achieve these goals, the real-time system controlling the ITER plasma discharges will be significantly more complex than the ones used at existing fusion devices," explains Axel Winter, who is responsible for the real-time plasma control software in the ITER team. "We are already working closely with teams here at ITER and in the Domestic Agencies to ensure that the real-time control system will also be able to serve the ITER diagnostics."   The real-time control system will use data from about 100 diagnostics to calculate the necessary control signals for the plant systems which can influence the plasma discharge, for example the power supplies for the magnetic coils, fuelling or heating systems.   This allows the discharge program—with a target duration of up to 1 hour—to be tailored to the needs of the scientists and engineers. "It will require a smart system capable of not only quickly counteracting fast plasma instabilities but also adapting the discharge program in real-time to make full use of the long plasma duration. In addition, the system needs to be robust, yet flexible, so we can continue to develop it over the course of the ITER lifetime, integrating our expanding knowledge, adapting the control systems to changing conditions, and rapidly implementing new concepts," adds Gerhard Raupp from IPP who, together with Axel, will manage the IPP-ITER Organization collaboration.   The six-year agreement was recently signed by ITER Director-General Bernard Bigot and IPP Scientific Director Sibylle Günter during a visit of an IPP delegation to the ITER site.The collaboration will be executed in three phases. After the development of the complex software infrastructure is completed in a first phase, it will be tested at the ASDEX Upgrade tokamak in Garching using a diagnostic as a test system during routine operation. Finally, the migration of ASDEX Upgrade's real-time control system to the new software infrastructure is foreseen, making ASDEX Upgrade an ideal test bed to develop and demonstrate control concepts for ITER using an identical software base.   IPP has a strong track record in the field. In 1988, the first fully digital plasma control system was implemented at ASDEX, followed in 2000 by the first plasma control system based on a modular software framework, which is also the conceptual vision for ITER. Axel concludes: "As both ASDEX Upgrade and ITER will use an identical software infrastructure, we can expect very strong synergies both for the development and testing of control schemes for ITER and for future training of ITER operators at an existing tokamak."  

Feeders are the lifeline of the ITER magnet system, relaying electrical power, cryogens, and instrumentation from outside of the cryostat into the powerful coils. Of the 31 feeders distributed all around the vessel, six will service the poloidal field coils. Each poloidal coil feeder consists of three principal units: the in-cryostat feeder, the cryostat feed-through and the coil terminal box which provides the housing for the connections of the magnets to other interfacing systems. "A lot of effort has gone into developing detailed manufacturing and quality assessment/quality control plans and documentation, and this effort has paid off," says Arnaud Devred, head of the ITER Superconductor Systems & Auxiliaries Section. Since the signature of the magnet feeder Procurement Arrangement in 2011, the Chinese Domestic Agency and its supplier ASIPP (Chinese Institute of Plasma Physics) have been progressing through the qualification phase, fabricating mockups as well as full-scale prototypes for the most critical feeder components. At the end of the qualification phase, a manufacturing readiness assessment is planned to assess the supplier's readiness to proceed to manufacturing for each component type. In early November, the first manufacturing readiness assessment took place for the cryostat feed-through for poloidal field coil #4 (PF4 Feeder CFT). The review panel, made up of experts from the ITER Organization, the Chinese and European Domestic Agencies, and external specialists, was chaired by Rem Haange, former head of the ITER Project Department and acting ITER Chief Operating Officer through 23 October. The event was celebrated as an important procurement milestone, as it follows five years of intense work to complete the design and carry out the qualification of key components and key manufacturing processes. In addition, this particular component—the cryostat feed-through for poloidal field coil #4—is the first magnet component needed on site because it needs to be brought into position before the completion of the cryostat base support ring. The component is scheduled for arrival during the third quarter of 2017. The review panel, made up of experts from the ITER Organization, the Chinese and European Domestic Agencies, and external specialists, was chaired by Rem Haange, former head of the ITER Project Department and acting ITER Chief Operating Officer through 23 October. Haange had been the Chair of the feeder Final Design Review as an external expert before joining the ITER Organization in January 2011.

The European Domestic Agency has released a series of video clips on manufacturing activities underway on the ITER toroidal field coils.   Filmed at the European winding facility in La Spezia, Italy, the videos document the winding, radial plate insertion, conductor wrapping and insulation, and radial plate laser welding phases of the manufacturing process.   The European consortium ASG (formed by ASG, Italy; Iberdrola. Spain; and Elytt, Spain) is progressing well on the fabrication of the double pancake windings that form the building blocks of ITER's massive D-shaped superconducting magnets. In September, Europe reported that 36 double pancakes had been wound (enough to assemble five toroidal field coils), 30 heat treated, and 28 successfully transferred into the radial plate grooves. The cover plate welding has been successfully completed on 19 of the double pancakes. (See more on the multiple-stage manufacturing process here). Europe is responsible for procuring 10 of ITER's 18 toroidal field coils. View the time-lapse videos on the European Domestic Agency website.

At its seventeenth meeting in November 2015, the ITER Council named ​Won Namkung, from Korea, to succeed Robert Iotti as Chair effective 1 January 2016. Dr Namkung is a Professor Emeritus of Physics at Pohang University of Science and Technology (POSTECH) in southwest Korea and Executive Adviser at the Pohang Accelerator Laboratory. In the course of his career, he contributed to the construction of KSTAR, Korea's first all-superconducting tokamak. He has also been involved in Korea's contribution to ITER, serving as the project's first Management Assessor. Dr Namkung received his BS in Physics from Seoul National University and his PhD in Physics from University of Tennessee. Robert Iotti, from the US, finishes his two-year term as Council Chair on 31 December 2015.

--Raphael Rosen, PPPL A team of physicists led by Stephen Jardin of the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) has discovered a mechanism that prevents the electrical current flowing through fusion plasma from repeatedly peaking and crashing. This behaviour, known as a "sawtooth cycle," can cause instabilities within the plasma's core. The team, which included scientists from General Atomics (San Diego) and the Max Planck Institute for Plasma Physics (Germany), performed calculations on the Edison computer at the National Energy Research Scientific Computing Center, a division of the Lawrence Berkeley National Laboratory. Using M3D-C1, a program they developed that creates three-dimensional simulations of fusion plasmas, the team found that under certain conditions a helix-shaped whirlpool of plasma forms around the centre of the tokamak. The swirling plasma acts like a dynamo—a moving fluid that creates electric and magnetic fields. Together these fields prevent the current flowing through plasma from peaking and crashing. The researchers found two specific conditions under which the plasma behaves like a dynamo. First, the magnetic lines that circle the plasma must rotate exactly once, both the long way and the short way around the doughnut-shaped configuration, so an electron or ion following a magnetic field line would end up exactly where it began. Second, the pressure in the centre of the plasma must be significantly greater than at the edge, creating a gradient between the two sections. This gradient combines with the rotating magnetic field lines to create spinning rolls of plasma that swirl around the tokamak and gives rise to the dynamo that maintains equilibrium and produces stability. Image: A cross-section of the virtual plasma showing where the magnetic field lines intersect the plane. The central section has field lines that rotate exactly once. (Credit: Stephen Jardin) Read the full article at PPPL.