ITER Newsline / 14 June 2018


Neutral beam test facility
First ITER test bed enters operation

For all those who had contributed to designing and building the world's largest negative ion source, it was a deeply symbolic moment. ITER Director-General Bernard Bigot pressed down, and sent into motion a chain of signals that resulted in the appearance of a brief plasma on the screen. The negative ion source SPIDER was officially launched at the Consorzio RFX facility in Padua, Italy, in the early afternoon of 11 June. 'Where else but here in Padua would we want to celebrate such a technological breakthrough,' wondered the ITER Director-General in his address. 'Padua—home to such scientific figures as Nicolaus Copernicus and Galileo Galilei who, I'm sure we all agree, changed the cultural and scientific history of humanity. Fusion energy, too, has the potential to change the course of mankind, and ITER will pave the way.' The main hall of the PRIMA Neutral Beam Test Facility had been cleared and turned into a staged theatre to welcome the 300 guests that had made their way to participate in the event. As the guests took their seats, the machine's vacuum pumps made a steady 'breathing noise' behind the thick concrete wall that hid the SPIDER equipment, a long-term vision now come to life. The importance of the event for the ITER Project, for science in general, and for the host region could be measured by the line-up of speakers: Francesco Gnesotto, the president of Consorzio RFX, was followed in short succession by the mayor of Padua, Sergio Giordani; European MEP Flavio Zanonato; Carles Dedeu i Fontcuberta from the European Commision; Salvatore La Rosa from the Italian Ministry for Education, University and Research; and representatives of the ITER Organization and the European and Indian Domestic Agencies. Finally the technical team in the control room, assembled around Consorzio RFX Director Piergiorgio Sonato, connected in to the event by video conference. Sonato explained what the audience would be seeing—a short plasma-generating experiment that would be evidenced by a flash of light on the screen. Next month, he explained, this type of experiment will be run for longer periods to begin extracting negative ions. The countdown started, the button was pressed and—a few seconds later—the experiment was confirmed as a success. As the music of Vivaldi played in the background, a thick concrete door opened to review the SPIDER vessel and beam source. When the microphone was handed around, pride in the first-of-kind technological achievement—as well as in the success of the international collaboration that made it possible—was tangible. 'I am really proud to see this achievement,' said the ITER Director-General. 'As you know we are committed to deliver, and the most important for us is to keep the trust of all the stakeholders. When we complete something on time, according to specification and schedule, it is the best possible outcome.' SPIDER is one of two test beds planned on the ITER Neutral Beam Test Facility in Padua. All contributions are voluntary (i.e., outside the scope of in-kind contributions to the ITER Project): Italy and Consorzio RFX have provided the facility and a large contribution towards the personnel; the European Domestic Agency has financed and procured most of the components, building on the expertise of European industry and research organizations; the Indian Domestic Agency has contributed the calorimeter and the acceleration grid power supply; and the ITER Organization is responsible for the design and oversight. See this webpage for full information on the experiments planned at PRIMA. View a video prepared for the inauguration in this week's Newsline, or click here. A brochure on SPIDER can also be downloaded here.

Fusion machines
Searching for the perfect shape

The perfect magnetic trap doesn't exist. Over time plasma physicists have experimented with different types of cylinders, magnetic mirrors and circular or helical shapes to optimize control of the plasma. While R&D continues on many fusion energy configurations, the torus-shaped tokamak has yet to be dethroned as the highest performing fusion device. What is the objective of a magnetic fusion trap? Fusion plasmas must remain in suspension in order to avoid contact between the superheated particles and the material vessel. As plasmas consist of electrically charged particles—positive ions and negative electrons—they can be controlled and confined by magnetic forces. ITER's magnetic 'cage' will be created by superconducting coils shaping and controlling the plasma, as well as by electrical currents circulating within. In the early days of plasma research, physicists experimented with cylindrical systems—devices with coils around a tube that created linear magnetic fields running parallel to the vessel body. But the 'holes' in the magnetic trap—the cylinder's open ends—resulted in high losses of energy as the plasma particles escaped. Magnetic mirrors at the two openings of the device, essentially reflecting particles back into the cylinder, were an early attempt to solve the problem. Still, there were substantial losses of energy, despite the mirror trap. The next solution came in the form of a closed system in which the magnetic field lines turn in on themselves—like a snake biting its tail—allowing the particles to spin indefinitely. The stellarator, with its complex geometry of twisted coils, was the first device to apply this shape, but using a complicated physical configuration that makes stellarators extremely challenging to build. The torus-shaped tokamak, invented in Russia in the 1950s, also enables magnetic field lines that close to form a ring, but its smooth and symmetrical structure is much easier to build than the stellarator. However, there were early difficulties also with the tokamak design when experiments showed that electrically charged particles—while moving within the torus along magnetic field lines—would eventually drift off vertically, hit the walls and be lost. This problem was resolved by inducing an electrical current inside the plasma, creating an additional magnetic field perpendicular to the current. As a result, the particles move in a three-dimensional curve, very much like a helix, and remain within the torus. Today, the tokamak design rules supreme in the world of fusion. While innovators continue to experiment with a variety of devices, fuels, and approaches, the hydrogen-fuelled tokamak fusion reactor remains the device with the best performance on record so far.

ITER Robots: pre-teens can too!

Made-from-scratch movers and carriers were again on display near ITER, as the younger set took up the ITER Robots challenge. From two participating schools in 2012 to sixty-five in the most recent edition, the ITER Robots contest has continued to expand and is now firmly established in the regional pedagogical landscape. Under the supportive eye of an adult mentor, students work in teams over much of the year to design and program robots to carry out the ITER-like handling tasks described in the contest's technical specifications. Along the way—in addition to learning a good deal about the kind of challenges ITER engineers face—the students learn valuable technical and interpersonal skills. For the first time, organizer Agence Iter France has expanded its successful concept to benefit 4th, 5th and 6th graders. More than 320 people were present on 5 June to support the first Junior Challenge—10 teams competing in robotics, general culture and communication (creating a stand). ITER Robots Junior, like the original, is organized in partnership with the ITER Organization, the Aix-Marseille academy and the Institute for Magnetic Fusion Research (IRFM, CEA).


Enhancements underway at DIII-D tokamak

One of the most flexible and highly instrumented fusion research reactors in the world is undergoing major enhancements that will pave the way to future fusion power plants. The DIII-D National Fusion Facility is the largest magnetic fusion experiment in the United States. In May, work began on a series of machine enhancements that will make it possible to commence new studies of the physics of future fusion reactors. That will help scientists understand how to achieve high fusion power in the ITER and how to sustain such regimes indefinitely in the fusion power plants that will follow ITER. The planned year-long activity will enhance DIII-D systems by adding increased and redirected particle beams and radio frequency systems to drive current and sustain the plasma in a so-called 'steady state.' The improvements will also expand capabilities with the installation of new microwave systems to explore burning-plasma-like conditions with high electron temperatures. This will allow researchers to explore how to achieve higher pressure and temperatures while increasing control of the plasma, conditions critical to sustained fusion operation. See the recent press release on the General Atomics website.

Looking for resilent materials

Scientists at Oxford University, in collaboration with the University of California Santa Barbara, are studying the impact of radiation on the properties of materials. Through their research, they hope to contribute to developing better, more resilient materials for nuclear fusion. See this animation by Oxford Sparks to get an insight into how it is done.

European Domestic Agency: Interns wanted!

Are you a university graduate in the field of nuclear engineering, physics, administration or communication? Do you want to put your academic experience into practice at ITER, the most ambitious international energy project? Then this traineeship may be for you. The European Domestic Agency for ITER is looking for physicists, engineers, lawyers, communicators and experts in human resources, finance and procurement who are interested in hands-on experience in an exciting international and multicultural environment. The traineeship is paid and will last from between four to nine months starting in October 2018 at any of the three locations: Barcelona, Spain; ITER site (France); or Garching, Germany. The deadline for applications is 25 June 2018. For more information and a complete list of opportunities click here.


Inauguration of the SPIDER ion source


College of Engineering, University of Wisconsin-Madison

Amy Wendt envisions a bright renewable energy future for burning plasma


Fuzijski reaktor ITER (25' video, Ugriznimo znanost)

Il Mattino di Padova

Un progetto da 22 miliardi di euro

Il Mattino di Padova

A Padova ora si "accende" l'energia pulita delle stelle


Italia inicia las pruebas para generar el "pequeño sol" que activará ITER

La Provence

Iter, un accélérateur d'emplois en Provence

Corriere Della Sera

Padova, parte Spider la «sorgente» italiana del nucleare pulito

ITER Newsline and ITER Mag are publications of ITER Communication.
Suggestions are always welcome at