It requires quite a bit of self-confidence to climb the stage in the ITER amphitheatre and face 200 employees of the world's largest fusion project with the question: Do we still need fusion? But Friedrich "Fritz" Wagner had not come to southern France to tell ITER staff it was time to go home—on the contrary. Equipped with some very precise facts and figures, the German fusion scientist told the story of the current transformation from nuclear to renewable energies taking place in his home country. And who would know the maths behind the German Energiewende better than Wagner? Having started his career in low-temperature physics he soon aimed for a warmer future in fusion research. In 1975 Wagner joined the Max Planck Institute for Plasma Physics (IPP) and became head of the ASDEX tokamak experiment in 1986. But it is not for his position that the name Fritz Wagner is known to every fusion student around the world—it is for his discovery of a high confinement regime called H-mode in 1982, a phenomenon "so much of our lives now depend on," as the head of ITER Plasma Operation, David Campbell, said in his introduction. Wagner later joined the stellarator branch of the IPP as head of the Wendelstein 7-X project. Wagner holds the renowned Hannes Alfvén Prize from the European Physical Society (which he headed for many years). Today Fritz Wagner, although officially retired, tours the world as a prominent advocate for fusion. What was the major conclusion of his presentation to ITER? See below! Mr Wagner, in your talk you sketched the essence of the German "Energiewende"—the transformation from a nuclear- and fossil-based energy market to a renewable energy market. From your observation, what is happening in Germany? Germany has doubled its electricity producing power capacity by adding nearly 80 GW of wind and photovoltaic (PV) power. This process is driven by the fit-in-tariff system, a subsidy for renewable energy sources paid by the electricity consumer. Some of the consequences of this transformation are rather unexpected. First, the operation of the thermal power stations (notably gas) becomes uneconomical and, instead, more lignite (low energy density coal) is burned—increasing, instead of decreasing, our CO2 emissions. German CO2 emissions have increased in parallel to the expansion of renewable energy sources. Another consequence is the rising price of electricity; German households pay (with Denmark) some of the highest prices today in Europe. The subsidy for renewable energy sources paid by the consumer reached EUR 24 billion in 2014. (In comparison, the spot market value of the electricity produced by renewables was only EUR 3 billion.) Wind and photovoltaic are also intermittent sources. The national grids aren't complete enough to transfer the electricity produced in the north of the country through wind power, for example, to the south where it is needed. Electricity cannot be stored easily; meaning that on good days when surplus is produced, electricity is sold at negative prices. The economic viability of the Energiewende relies on large-scale storage, which is still in the research stage. A final important consequence of the renewable energy strategy, in my mind, is the visual impact of wind farms on the northern landscape. Will Germany one day be able to rely to 100 percent on renewables? For the moment, we only produce a fraction of the energy we need from renewables. The answer long-term, again, hinges on storage. With large-capacity storage it is in theory, possible. But in practice, the numbers show that a backup system will always be needed to meet the load in periods of un-cooperating natural conditions. I think a realistic estimate would be relying on renewables for up to 40 percent of national demand. A CO2-free energy supply is certainly something everybody wishes for, but can we afford this goal? Which implications would it have for the price of electricity? Several countries in Europe produce electricity CO2-free at affordable prices—France, Switzerland, Sweden and Norway. They are already where others like Germany want to be in 2050. They use nuclear and benefit from hydroelectricity. To reach the same level of CO2 production during electricity generation, Germany would need 100 percent renewables and storage at large scale. This will make the electricity price high for Germans and will result in strong variation in electricity prices paid across Europe. So, in conclusion, will we need fusion energy? We have only four CO2-free options: renewable energy sources (wind and photovoltaic); fission with fast neutrons; carbon-capture and storage; and fusion. All four have pros and cons and are not completely developed. Research must be pursued vigorously in each option because research represents  the only safety insurance we have. But with the predicted increase in world population by 2050, the supply situation becomes even more serious. I doubt that renewables will be able to exclusively provide the energy needed. I think fusion energy is an important supplement. Who will make the race to the grid first? The stellarator or the tokamak? Stellarators also rely on the success of ITER. It will not be possible to point to Wendelstein 7-X as another option in the case that ITER fails. Now, can a case still be made for the stellarators if ITER achieves Q=10 with bravado? Yes, if steady-state operation or disruptions pose a problem. If stellarators demonstrate good confinement, operate nicely for long pulses without impurity accumulation and density control issues, and—in addition—operate in the high-density H-mode regime of Wendelsteinn7-AS (the precursor to Wendelstein 7-X) then, yes, stellarators will have a good chance. I expect that by 2030 the world energy problem will be so obvious to all that the fusion community will be praised for its twofold development strategy, and fusion scientists will be urged to continue developing both tokamaks and stellarators as quickly as possible.

One of the big challenges to the monitoring and protection of the large and complex superconducting components of the ITER magnet system is the transmission of the voltage signals from cryogenic to room temperature in a challenging environment involving high voltage, high vacuum, high magnetic field and radiation.   In ITER, the magnet instrumentation cables extend from the magnet cold mass in the insulation vacuum to the outside world at atmospheric pressure. The transition between vacuum and atmospheric pressure takes place at the level of the so-called  instrumentation feedthroughs.   The operating insulation voltage for the feedthroughs varies from 4 kV to 30 kV, derived from the electro-dynamic analysis of the ITER magnetic circuits. Based on these voltage levels and the number of wires in the cables, the feedthroughs are divided in five different types.   Other operating parameters are: vacuum up to 10^-6 torr, magnetic field up to 100 mT, and integrated radiation gamma doses of 1 kGy during the operational life time of the ITER machine (20 years).   The ITER requirements made procuring the feedthroughs challenging, as no commercial solutions were available at the time. Approximately 1,000 units, distributed all around the Tokamak Complex, are needed for ITER.   Detailed R&D programs for the qualification of a prototype design were launched in 2009, followed by the qualification of potential vendors for series production. In 2014, the ITER Organization awarded the contract to Ceramtec North America Corporation (US).   A few design iterations and sub-assembly tests were carried out to optimize design and manufacturing processes. After design approval by the ITER Organization, Ceramtec has produced two samples for the 6 pin 30 KV rating, identified as a type D variant.   The feedthroughs have passed all of the thermal cycle tests and leak tests at various stages of manufacturing and assembly, followed by a final electrical test at Ceramtec. The feedthroughs were connected to prototype high voltage cables provided by ITER for the electrical testing, before being sent to the ITER Organization for additional type tests and further validation.   It was an exciting moment for the ITER magnet instrumentation team when it received the first shipment of two high voltage feedthrough samples! "The sheer size and weight of these feedthroughs give a pretty good idea of the challenges ahead for the installation and commissioning of the high voltage magnet instrumentation. The achievement of this critical milestone and the reception of these two prototypes at ITER show the good and timely progress of the magnet instrumentation team and its readiness to process with series production," says Arnaud Devred, Superconductor Systems and Auxiliaries section leader.   The next steps for these feedthrough prototypes will be a re-check of vacuum leak tightness in the recently set up vacuum lab in the ITER Headquarters basement, and comprehensive high voltage testing at the Magnet Infrastructure Facilities for ITER (MIFI), hosted at the neighboring CEA research centre.

About ten years from now, a signal from the ITER Control Room will trigger the operation of eight gyrotrons. Each gyrotron will generate a microwave beam over a thousand times more powerful than a traditional microwave oven.   These microwave beams will travel along 160 metres of waveguide and then launch into the ITER Tokamak to ionize the neutral gas and generate the very first ITER plasma, in much the same way that a spark plug ignites your car motor. The eight gyrotrons in place for ITER's First Plasma will be joined by sixteen others to initiate every plasma during operation, as well as provide heating to the plasma, drive current, and stabilize plasma instabilities.   Russia developed the first gyrotron back in 1964, generating 6W at 10GHz for continuous operation. Since then, scientists around the world have steadily increased gyrotron output power, which now approaches 2MW.   The Japan Atomic Energy Agency, in collaboration with Toshiba, manufactured the first gyrotron to demonstrate 1MW for >400 s, compatible with ITER requirements of 2006. Last month, an advanced gyrotron design was presented to an international team of experts and representatives from the ITER Electron Cyclotron Section and interfacing areas. Of four contributing parties to the 24 ITER gyrotrons (Japan, Russia, Europe, and India), Japan is the first to present its gyrotron at the final design stage. (Final design reviews for the others are planned shortly.)   The Japanese Domestic Agency Final Design Review panel included electron cyclotron scientists from the DIII-D tokamak (US), the Large Helical Device (LHD, Japan) and the ASDEX-Upgrade tokamak (Germany) along with representatives of the ITER Organization. The other Domestic Agencies involved with gyrotron development were also present at the review meeting. The panel assessed the Japanese design as mature and issued no category 1 chits.   This first Final Design Review in Japan concentrated on the gyrotron tube and assembly; a second is planned to focus on the interface with the high voltage power supply and related devices. In 2015, the Japanese Domestic Agency expects to initiate the call for tender procedure for the manufacturing of the first two gyrotrons, which will arrive on the ITER site in early 2018. These gyrotrons will then be integrated with high voltage power supplies (procured by India and Europe), transmission lines (procured by the US), and launchers (procured by Japan and Europe).

Half hidden amid the oaks and pines of the forest south of the ITER platform, the logistics platform warehouse glitters in the late afternoon sun.   The 150-metre long, 60-metre wide, 12-metre high building will be completed by late autumn, providing 9,000 square metres of storage for average-size ITER components.

​The February issue of Fusion for Energy newsletter is now online. Find out how contractors feel about ITER's business potential, read about top management changes in Barcelona, catch up on design reviews and more.

Operators at EAST, the Chinese superconducting tokamak, announced in the February issue of the EAST Newsletter that the auxiliary heating system has passed a national acceptance review and is officially stamped "well qualified" to enter operation. Construction on the auxiliary heating system, which consists of 4 MW neutral beam injectors and 6 MW lower hybrid current drives, began in November 2011. The additional heating power on EAST will enable high-level plasma physics research including testing for ITER. The acceptance panel commended the construction, complete "with high quality, within budget and one year ahead of schedule." Aiming at long-pulse plasma discharges, a series of experimental techniques has been developed on EAST in recent years. Tremendous efforts have been made during past two years to enhance EAST's capabilities—nearly every sub-system except superconducting magnets has been upgraded or modified to enable higher performance and truly steady state operation. Read the full article in the February issue of the EAST Newsletter, attached.

On 3 February 2015, FuseNet (the European Fusion Education Network) and ENEN (the European Nuclear Education Network) signed a Memorandum of Understanding at the General Assembly meeting of FuseNet that was held at the Culham Centre for Fusion Energy. It marked the start for further cooperation between the European fusion and fission education networks.   ENEN is older than FuseNet, but similar in many ways. As the nuclear aspects of fusion energy become more prominent -- ITER is truly a nuclear device -- the need to provide fusion students and engineers with proper education and training in this field becomes ever larger. Likewise, nuclear engineers are in high demand in the fusion enterprises now, and they may benefit from a fusion training.   Prof. Walter Ambrosini (president of ENEN, left) and Prof. Niek Lopes Cardozo (president of FuseNet, right) sign the Memorandum of Understanding between the two networks.   Read more on the FuseNet website.