Forty metres above ground, in an aerial lift, a worker suddenly feels sick and loses consciousness. His colleagues on the ground immediately realize that something is wrong, but a technical incident prevents the lift from being operated at a distance. The worker is stranded, alone, without anyone knowing how serious his condition is. The ITER worksite might one day face such an emergency and everything must be in place to manage this type of situation swiftly and efficiently. That's why, on Tuesday 9 June, a security drill was organized on the ITER platform to test the response capacity of the different teams that intervene in an accidental situation.   "The drill scenario, elaborated jointly with the people directly responsible for worksite safety, multiplied the technical constraints," explains Christophe Ramu, acting head of ITER's Security, Health and Safety Division. "The high pillars of the Assembly Hall form one of the most inaccessible environments of the worksite, one that can only be reached by air lift. But air lifts can only accommodate a small number of people. And we added a further complication to our exercise—a technical problem, which prevented the air lift from being operated from the ground."   The "evacuation drill" began at 9:30 a.m. As soon as workers on the ground noticed that something was wrong, they placed a call to the ITER Security Command Post. The number for this post, which is manned around the clock, is inscribed on the back of all ITER access badges.   The Security Command Post immediately transmitted the information to the on-site Emergency Response Team and to the worksite nurse, who both rushed to the site of the accident. Security guards were placed on the alert to be ready to welcome external support teams, if necessary.   "By this point in the exercise," says Ramu, "we already had an idea of the situation and of the difficulties we were faced with." The local fire brigade paramedics in Saint-Paul-lez-Durance were alerted and asked to bring in a specialized unit called the Intervention Group in Hazardous Environments (in French, the acronym GRIMP reads like "CLIMB"). The unit's members are experts at rope climbing and evacuation.   While the specialized unit was on its way, the Emergency Response Team had reached the stranded worker in a second air lift. Their mission was to secure the worker and to assess his condition. The worksite nurse followed to perform the first response actions needed to stabilize the victim.   By then, the experts in rope rescue had arrived. Their job consisted in transferring the victim onto a rigid "scoop" stretcher; the stretcher was then slowly lowered to the ground by crane, with a member of the GRIMP team, attached to his own rope, present the whole time.   More than two hours had elapsed between the first alert and the victim's evacuation. "This might seem like a long time," says Bertrand Portehault, Health and Safety Protection coordinator at APAVE, the company responsible for safety on the ITER worksite. "But the accidental scenario we created was deliberately delicate and the techniques were quite time consuming. The most important thing is always to secure and stabilize the victim in the minutes that follow the incident."   The drill, which mobilized some 20 participants, demonstrated the ability of in-house and external teams to coordinate their action into a fluid and efficient response sequence.   In construction work, national statistics show that the ratio of accidents per number of hours worked is 45 per million. On the ITER worksite it is four times lower. But accidents do happen and everything—like last Tuesday's spectacular drill—must be done to mitigate their consequences.   View the slideshow below.

In the ITER Tokamak, the challenges of vacuum can be found everywhere: in the 1,400 m³ vacuum vessel where fusion reactions will be produced; in the 8,500 m³ cryostat that will act as a giant thermos to keep the intense cold inside the superconducting coils; and in penetration flanges, filters, valves, gauges, diagnostic equipment, materials...   Vacuum is so important to a fusion device that it takes more than just technical competence to apprehend it—one needs a broad "vacuum culture" and an understanding of what vacuum is about.   The first three-day "Vacuum for Fusion" training session that was organized at ITER on 9-11 June aimed precisely at that. "We developed this course to provide an overview of the complete science and engineering of vacuum technology," explains Robert Pearce, head of the ITER Vacuum Section. "Through lectures, presentations and practical sessions in the vacuum lab, we went from the fundamentals to the nitty-gritty of the engineering techniques."   Twenty-four participants from the European and US Domestic Agencies and from different departments of the ITER Organization learned how, when it comes to the ITER Tokamak, vacuum touches "almost everything—from plasma to magnets." Over the course of three days, they explored vacuum fundamentals and material properties, and experimented with leak detection, metal sealing, and gas analysis.   Twenty-four participants from the European and US Domestic Agencies and from different departments of the ITER Organization learned how, when it comes to the ITER Tokamak, vacuum touches almost everything... "The lecturers have a lot of experience," explains Francina Canadell, a young engineer with the Vacuum Pumping Group at the European Domestic Agency. "They have helped us to put the concepts into context. Take outgassing¹ for instance — we deal with outgassing on a daily basis with the suppliers that are manufacturing components for ITER. But what is the essence of outgassing? What are the physics underlying the process? This is the kind of thing that we learned during the session."   For the young engineers at an early stage of their career in vacuum, or for the more seasoned experts working on the design, procurement and assembly of vacuum components, all enjoyed the overall approach of the session designed by Robert Pearce and his team. And—most important of all—the training session made it clear why vacuum, in Pearce's own words, "is absolutely key to ITER success."   Given the level of interest in the first training session the program will be offered again in the future, open to all ITER Domestic Agencies.   ¹ Outgassing is the process by which materials release the gas particles that are trapped on their surface or within their structure.

The safest place to be when lightning strikes a crane is ... in the crane's cabin itself. Like his colleagues in the other cranes on site, M'hamed Harit, a crane operator for 30 years, was where he was supposed to be. When an "orange alert" is sounded to signal the approach of a storm, the instructions are clear: operators must remain in their cabin, which acts as an insulated Faraday cage protecting them from the electrical discharges of the lightning bolts.   "I've sat in my cabin through many a storm," says M'hamed, "but that one was the worst I ever experienced. The thunderclaps were so loud, the lightning bolts so bright, that I felt like I was caught between bombs and a mega fireworks display." Was he frightened? "Yes, I must say I was. I pulled down the curtains and took refuge in a small, windowless recess at the back of the cabin."   The orange alert had sounded at 2:08 p.m. and was upgraded to red at 2:29 p.m. The storm reached a peak about an hour later, when Graeme Vine, from the ITER vacuum team, took this exceptionally well-timed picture from his third floor office. By 5:24 p.m. the red alert was lifted and crane operators were contacted on their personal cell phones—as most of the equipment (including radios and the lifts) had been knocked out by the electrical storm.   It was past 6:00 p.m. when M'hamed eventually made it to the ground. "I was still a bit apprehensive. It usually takes me 15 minutes to climb down the crane's ladder when I don't take the lift. This time, I think I made it in 5 minutes flat..."   The cranes  were back to functioning normally two days after the storm, thanks to the materials service of the VFR consortium, which was able to intervene rapidly.

Read more about the diamond disk fabrication process on the European Domestic Agency website. If the legendary king Midas were alive today, he might be jealous of what a company in Freiburg, Germany is achieving today. Midas could turn an item into gold, while Diamond Materials can turn methane into diamond.   During the process, a microwave plasma is used to dissociate methane. With the help of atomic hydrogen, the carbon atoms arrange themselves to form a thin homogeneous diamond layer that grows at a rate of a few micrometres per hour. After a few months the result is a diamond disk, ranging in size from 40 to 100 mm and with a thickness of 1 to 2 mm.   Aside from its beauty, diamond is nearly unbreakable, transparent and with a capacity to dissipate heat that is five times that of copper. The technology for growing diamond disks have been applied to various applications from dome tweeters in high-fidelity speakers, to vacuum barriers needed for ITER's electron cyclotron heating system.   The electron cyclotron system will help to heat the plasma up to 150 million °C by transferring the energy from electromagnetic waves into the electrons of the plasma by injecting an unprecedented 1 to 1.5 MW of power along 56 guiding beamlines, or tubes.   The electromagnetic waves, which travel in a manner similar to light, will pass through synthetic diamond windows measuring 80 mm in diameter. The windows have a double function—ensuring the efficient passage of the waves for durations of up to 3,000 seconds, and ensuring the leak tightness of the vacuum vessel.   The core of the window assembly is the 1.1-millimetre-thick synthetic diamond disk, which performs the double function of a vacuum boundary and ≤1.5 MW beam transmission. The high thermal conductivity of diamond is essential to evacuate the absorbed power from the passing microwave beam, with transmitted power density up to 500MW/m2.   "The diamond disk will be integrated into a mechanical structure which needs to be extra robust and mechanically stable in order to withstand the harsh Tokamak environment and ensure that the window does not fail. Vacuum-tightness is also of upmost importance since the window will confine the tritium gas used for fuelling the ITER plasma," explains Gabriella Saibene, European Domestic Agency project team manager for antennas and plasma engineering.   The European Domestic Agency is responsible for procuring 60 diamond windows for ITER's electron cyclotron heating system. In collaboration with the ITER Organization and the Karlsruhe Institute of Technology (KIT), and after ten years of R&D, the European agency for ITER has entrusted the manufacturing of two prototype diamond disks to Diamond Materials, where manufacturing is proceeding well.   "The next step will be to carry out optical and mechanical testing, as well as check how the disk resists fractures and how well it brazes (joins with metal), as it needs to be attached to a copper mechanical structure," according to Saibene. "Conclusion of the testing on the two disk prototypes is expected in less than one year."  

​The signature nuclear fusion experiment at the Princeton Plasma Physics Lab is expected to relaunch this summer after being shuttered for upgrades for about three years. When it reopens, the reactor there will be the most powerful of its kind in the world, lab directors say. "We expect to start up probably toward the end of June. We'll do the initial tests that will get us toward research operations, and (research) will start later in the summer, let's say August time frame, maybe mid-September," said Adam Cohen, chief operating officer for the lab. The National Spherical Torus Experiment, also known as NSTX, is a plasma in the shape of a cored apple heated to between 50 million and 100 million degrees. The experiment's $94 million upgrade bought a stronger magnet for the plasma's nuclear reactor and a second neutral beam accelerator to heat plasma even further. Read the whole article on the Newsworks website.

​As part of a Scientific Discovery through Advanced Computing (SciDAC) project, a partnership between the US Department of Energy's Advanced Scientific Computing Research Leadership Computing Challenge and Fusion Energy Sciences programs, researchers are using the Oak Ridge Leadership Computing Facility's (OLCF's) Titan supercomputer to try to get closer to producing sustainable fusion for electricity.   The project, led by Brian Wirth, a researcher with the University of Tennessee and DOE's Oak Ridge National Laboratory, brings researchers from various organizations together to work on different aspects of the ITER experimental fusion reactor. ... Wirth and his collaborators are using Titan, a Cray XK7 supercomputer capable of 27 petaflops, or 27 quadrillion calculations per second, to shed light on how fusion plasma interacts with the materials used to build the reactor. Specifically, they're investigating how tungsten—one of the toughest materials known—will be affected by the plasma over time.   As helium particles bombard the tungsten wall, they begin to form clusters within the material. Once a helium atom is embedded in the wall, it attracts other helium particles. When enough helium is bunched together, it can "knock out" a tungsten atom from its normal position within the material, forming a nanoscale cavity, or hole, within the tungsten.   Read the full report published on the Oak Ridge National Laboratory's website here.

Ten years ago this month, a group of industrial nations agreed on the location for the world's largest nuclear-fusion experiment: ITER, the International Thermonuclear Experimental Reactor, which they had decided to build jointly. Today, roughly €4 billion worth of construction contracts and €3 billion in manufacturing contracts worldwide are underway and the first large components are being delivered to the site at St-Paul-lez-Durance in southern France. Faced with slippage in the schedule—despite the best efforts of the more than 2,000 dedicated people working on ITER—in March 2015 the ITER Council moved to appoint Bernard Bigot, from France, to the top management position of the project. In this Comment in Nature, published on 11 June, the new ITER Director-General explains how he will strengthen leadership and management to refocus the project's aim of harnessing nuclear fusion.