For some of ITER's nuclear safety control electronics, it has been rocky weather recently. In the climate-controlled chambers of Applus+ Laboratories in Barcelona, control logic components have been undergoing fast temperature variations between -25°C and 70°C, then weathering 70° C heat for ten days, followed by damp heat for six days, and finally a return to -25°C for several hours. And if that wasn't enough, vibration tests have subjected the devices to mechanical stresses equivalent to those expected over the entire lifetime of ITER. Although not common for electronics, these conditions are intended to submit the components to aggravated environmental conditions, effectively "ageing" them as if they had been used for several decades in industrial conditions. The rough treatment is the first step in a series of tests intended to demonstrate that ITER's control logic electronics will continue to perform their functions flawlessly in case of a seismic event. The ageing tests, which began in July, will be followed by seismic tests in 2016 as part of environmental qualification that the Control System Division is performing with its contractor, the Spanish consortium Empresarios Agrupados/Inabensa.  The climate-controlled chamber for fast temperature variations at the Applus+ Laboratories in Barcelona, where the weather can vary from -25°C to 70°C. As a nuclear facility, ITER has categorized the components that keep the facility in a safe state and prevent or mitigate nuclear risks to humans and the environment as Protection Important Components (PIC). The Nuclear Safety Control System (SCS-N) is the system charged with detecting incidents or accidents and controlling all the active actions needed to prevent or mitigate those situations, and the tested electronics are the bricks used to build the system. The Nuclear Safety Control System will be delivered primarily by the ITER Domestic Agencies (90 percent), with approximately 10 percent procured by the ITER Organization Central Team. To support the Domestic Agencies in the procurement of the system and mitigate integration and qualification risks, the ITER Organization has selected two different technologies for the implementation of PIC control logics. In both cases, looking for cost effectiveness, the Central Team selected best-in-class industrial products through international call for tenders and is now performing the prequalification activities. The products (HIMA Planar 4 safety modules for highest importance PIC functions and Siemens Safety PLC for lower) can be used by all Domestic Agencies. By respecting applicable technical rules in order to stay inside the prequalification demonstration, qualification processes will be facilitated. The Central Team will continue to work on the demonstration that the product design, testing, and manufacturing all meet the requirements for the project's nuclear safety Instrumentation and Control (I&C) functions and the licensing of the system. And the samples will continue to weather demanding ageing tests. After the temperature variation, they will be subjected to prolonged operation for 40 days at maximum temperature and maximum voltage. These ageing tests will then be followed by stringent electromagnetic compatibility tests—representative of lightning striking the buildings—and finally magnetic field tests. In 2016, the contracting consortium will be charged with final seismic tests on full-size control logic cubicles.

One of the world's largest milling machines has been inaugurated at the Walter Tosto facility in Ortona, Italy. Called the PowerTec, it was specially designed and built by German tooling manufacturer Waldrich Coburg to mill the large stainless steel sectors of the ITER vacuum vessel.   Weighing 1,300 tonnes, PowerTec is one of the largest high precision portal milling machines ever built. The giant measures 50 metres in length, and is 18 metres tall and 22 metres wide. With a travel length of 35 metres and a maximum clearance of 10 metres—both in height and width—the PowerTec could easily clear a small home. But when it comes to handling ITER's high-tech components it's not only the sheer size that counts, it's also the precision.    The manufacturing of the ITER vacuum vessel requires extreme precision in order to be able to successfully integrate many in-vessel components such as the blanket, the divertor and the in-vessel coils; for most of these components tolerances are on the order of 1-3 millimetres. The dimensions of the milling machine inaugurated at the Water Tosto facility on 10 September were dictated by the dimensions of the vacuum vessel sectors themselves, each weighing about 450 tonnes and standing 12 metres tall. Of the nine ITER vacuum vessel sectors, seven will be built by Europe and two by Korea. In October 2010 the European Domestic Agency awarded its procurement contract to the European consortium AMW (Ansaldo Nucleare S.p.A, Mangiarotti S.p.A and Walter Tosto S.p.A).

When the hot, dense plasma in a fusion reactor hits the reactor's exhaust wall, dust particles will inevitably erode from the wall and be swept away by the plasma, or ionised gas. But how do these dust particles travel and where do they end up?   An international team has used sensitive cameras to produce the first ever fully resolved movies of dust motion in experiments with DIFFER's linear plasma generator Pilot-PSI (Nieuwegein, The Netherlands). The new data will feed into improved models for dust motion in the fusion reactor ITER.   "Dust particles are a few millionth of a metre (micrometre) in size. A challenge with detecting their minute motions is that you want to have the camera really close to the plasma," says Pilot-PSI operator Kirill Bystrov. In a complete fusion reactor, there is seldom the space to do that—instrumentation ports are too far away from this plasma-surface interaction region. "In Pilot-PSI, we can get the camera within half a metre of where the plasma hits the target."   The experiments reached a record spatial sensitivity of 9 micrometres per pixel. Previous experiments reached 200 micrometres to a few millimetres per pixel - ten to fifty times less sensitive than the record set in Pilot-PSI. This gives unparallelled information about how the dust particles roll, skip and bounce, and how they are influenced by the constant wind of plasma particles. This information will feed into predictive models for the dust motion, to clear up where it will collect and which reactor areas need special focus when cleaning.   The new measurements managed to clear up a mysterious form of motion where a dust speck kept its high temperature while sliding across a cooled surface. Intuitively, that just cannot happen: the particle should cool down to the surface temperature if it is in constant contact. It turns out the 200 micrometre per pixel resolution of the original measurements was to blame - where they saw a particle rolling or sliding in constant contact with the cooled surface, the more accurate 9 micrometre video clearly shows the dust speck bouncing across the surface and only cooling down a fraction when it strikes the surface between bounces.   Source: Highly resolved measurements of dust motion in the sheath boundary of magnetized plasmas; A. Shalpegin, F. Brochard, S. Ratynskaia, P. Tolias, M. De Angeli, L. Vignitchouk, I. Bykov, S. Bardin, K. Bystrov, T. Morgan   Read the full report on the DIFFER website.

At the US Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), world-leading fusion research resumes later this fall. After more than six years of planning and construction—including three years of building and 574,000 hours of labour—the National Spherical Torus Experiment-Upgrade (NSTX-U) is ready to play a critical role in the quest to develop fusion energy as a clean, safe and virtually limitless fuel for generating electricity. The $94 million overhaul has made the machine the most powerful spherical tokamak in the world. The upgrade has doubled its heating power and magnetic field strength, lengthened its operation from one second to five seconds and increased its plasma performance by a factor of 10. The improvements create a flexible research platform that will enable some of fusion's most outstanding puzzles to be directly addressed. "This achievement signifies the completion of an extremely successful challenge, which opens the door to a decade or more of exciting research," said PPPL Director Stewart Prager. "The world will now be watching to see if this experiment can serve to further improve our vision for future reactors." The new machine passed stringent tests to reach construction completion. On 11 May 2015, operators produced 40,000 electron-volts from a second neutral beam—a device used to heat the plasma—to demonstrate the first step in doubling the heating power. Then, on 10 August, engineers produced a 100,000-amp plasma—the fuel for fusion reactions. The twin achievements easily met the Key Performance Parameters (KPP) that the project had to satisfy to be completed. "This is not a little spherical torus anymore," said Al von Halle, the head of NSTX-U engineering and operations. "This machine has 10 times the capability of the original NSTX." [...] Continue reading on the PPPL website.

​General Atomics (San Diego) opened a facility making the world's largest magnets for rare public tours on 2 October in honour of the nationwide Manufacturing Day in the US. The factory in Poway, California, is making seven giant magnet modules, each weighing approximately 110 metric tons, for the $20 billion International Thermonuclear Experimental Reactor, or ITER, being built in France. Each magnet is made of 560 turns of superconducting cables made from stands of a rare niobium-tin alloy wound around a tube that will carry liquid helium. In operation, the magnets will be cooled to -269°C while 50,000 amps of power are applied.   Their role in the ITER Project is to contain a fusion reaction — literally trapping the sun in a bottle.   Photo by Chris Jennewein Read the full article in the Times of San Diego.

​On 28 September, the last lengths of Russian-procured conductor for ITER's toroidal field magnets were loaded onto trailers at the Kurchatov Institute in Moscow for shipment to the European winding facility in La Spezia, Italy. Through a Procurement Arrangement signed in February 2008 with the ITER Organization, the Russian Domestic Agency took on the responsibility of procuring 20 percent of toroidal field conductor lengths (28 lengths, including two dummies), plus testing and transport to the European winding facility. The building blocks of the ITER magnets are high-performance, internally cooled superconductors called CICC (cable-in-conduit) conductors, made up of bundled superconducting and copper strands that are cabled together and contained in a structural steel jacket. For the toroidal field magnets, the completed conductor will be wound into D-shaped "double pancakes," inserted into the grooves of a radial plate to hold it in place, stacked to form winding "packs," and finally contained in steel cases to form the completed coil. The shipment of three final lengths procured in Russia (pictured) completes Russia's longest-lead procurement campaign for ITER. -- Alex Petrov, ITER Russia