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F4E participates at the 1st Barcelona Energy Days

F4E Events - vr, 22/06/2018 - 02:00
Conference highlights fusion contribution to the future “energy transition”

Fusion machines | The second-hand market

ITER - ma, 18/06/2018 - 10:33



Whatever their size, fusion devices are fine pieces of technology that are complex to design and expensive to build. As research progresses and experimental programs unfold, however, scientific institutions routinely feel the need for machines with additional capacities, up-to-date equipment or exotic features. When an upgrade is not possible the "old" device appears on an unofficial "second-hand market," more often donated than sold—just like one might give away a perfectly functional but not-quite-cutting-edge computer to a nephew, a neighbour or a local association.
Russia, which built and upgraded tokamaks at a very fast pace throughout the 1970s and 1980s, has been one of the most generous contributors to this second-hand market.
In 1975, the Kurchatov Institute decommissioned an upgrade of TM-1—a machine that belonged to the early series of small tokamaks developed in the 1960s—and had it shipped to the Czech Academy of Science where it operated for some 30 years under the name CASTOR. (This grandfather of all tokamaks now serves educational purposes as GOLEM).
The LIBTOR tokamak, installed since 1982 at Libya's Tajoura Nuclear Research Centre, is the rechristened TM4-4 machine, which operated at the Kurchatov Institute from 1969 to 1973. Components from another Russian machine—the larger T-7 (1979-1985) and the first to be equipped with superconducting toroidal field coils— have been reused in China's HT-7.
A lesser known Russian machine, TVD, was handed over to Iran in 1994 where, in conformity with the long-standing tradition of giving fusion projects the name of mountains¹, it became Damavand, Iran's highest peak and a significant feature in Persian mythology.
Giving away second -and fusion devices is a way of planting the seeds of fusion research in aspiring countries. Portugal for instance, has been operating a small tokamak named ISTTOK since 1990 that is based on a machine that began its career in 1974 at the Dutch institute FOM (now DIFFER) under the name TORTUR (!).
In 1999 Brazil received the 20-year-old TCA tokamak from the Ecole polytechnique fédérale de Lausanne, in Switzerland. The device's French name (Tokamak à Chauffage Alfvèn) carries on in the Brazilian acronym TCABR (or TCA-Br). Brazil, which voiced interest in joining ITER in the late 2000s, also operates the NOVA-UNICAMP tokamak, which was the Nova II tokamak at Kyoto University, Japan, in a former life.
As they progress in their research, former "receivers" often become "givers." China for instance, after benefitting from Russian components for HT-7 and German components (from the original ASDEX) for HL-2A,  gave away HT-6B (1982-1992) to Iran, now installed as IR-T1 at Azad University in Tehran.
Nick Balshaw from the United Kingdom Atomic Energy Agency (UKAEA) tracks down "all the world's tokamaks" as a hobby. He has listed more than a dozen machines (including stellarators) that have changed hands in their lifetime—and not just once.
Take the present HIDRA (Hybrid Illinois Device for Research and Applications), which was transferred in 2014 from the Max Planck Institute of Plasma Physics (IPP) in Greifswald, Germany, to the University of Illinois in Urbana-Champaign.
The device, which was described by Physics Today as "a tokamak and stellarator rolled into one," had seen the light of day 40 years earlier in Grenoble, France, as a joint German-French-Belgian project under the name "Wendelstein Experiment in Grenoble for the Application of Radio Frequency Heating"—WEGA, in short.
WEGA operated in Grenoble for about 10 years, was transferred in 1984 to the University of Stuttgart, Germany, and resumed operation at IPP in 2001—still under the WEGA acronym, but with the "G" now standing for Greifswald and not Grenoble and the final "A" for Ausbildung ("training") in German.
By the end of 2013, as the latest incarnation of the Wendelstein project (Wendelstein 7-X) was nearing completion, WEGA was shut down and eventually sailed across the Atlantic. In sum, in over more than 40 years of existence the device has operated under four different roofs on two continents.
In the second-hand market, fusion devices are handed over free of charge (except for transportation costs, which are generally paid by the receiver). There is however one example of a "for sale" tag attached to a tokamak—and a hefty one at that.
Canada entered fusion research in the late 1970s, and by 1986 the Canadian Centre for Fusion Magnetics (CCFM) operated an experimental tokamak in the Varennes suburb of Montreal. This medium-sized machine, named Tokamak de Varennes, specialized in the study of plasma-wall interactions, and for more than one decade formed the kernel of CCFM activity.
Unfortunately, by 1997 the project had to be folded for lack of funding. CCFM was left with a perfectly operational machine on its hands, potentially worth millions of dollars, and it was ready to sell. Among the potential buyers was Iran, whose ambitious fusion research program had to rely on outdated machines.
The Iranian offer was in the range of USD 50 to 90 million (depending on the sources). It would have been enthusiastically accepted if the diplomatic context had been different: Iran was at the time under US-imposed sanctions and even in Canadian government circles, there was reluctance to realize the transaction.
The solution to the dilemma came from General Atomics: in order to upgrade its DIII-D tokamak, the company needed powerful gyrotrons ... of the kind, precisely, that equipped the Tokamak de Varennes.
Amputating one of the heating systems from the machine considerably reduced its operational value and, as expected, Iran pulled out of the deal.
As one final twist to the whole episode, the Tokamak de Varennes was transferred in 2001 to Canada's federal capital, Ottawa, where it now stands as one of the most spectacular exhibits at the Canada Science and Technology Museum — a unique example of a fusion machine on display for the general public.
¹ The tradition of giving the name of a mountain to a fusion research project originates with "Matterhorn", the secret program conducted at Princeton University in the 1950s. The choice reflected Lyman Spitzer's passion for mountaineering and called on the parallel between the difficulties of reaching the summit of a high peak and those of harnessing fusion energy. Several fusion projects have since been christened with mountain names—Wendelstein among them.

SPIDER is switched on and produces its first plasma!

F4E News - di, 12/06/2018 - 02:00
Consorzio RFX, F4E, ITER India and ITER Organization inaugurate the first experiment of the Neutral Beam Test Facility.

Neutral beam test facility | First ITER test bed enters operation

ITER - ma, 11/06/2018 - 22:49



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 Sonata, connected in to the event by video conference. Sonata 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.

Fusion and ITER take the stage at the EU Sustainable Energy Week, 7 June 2018

F4E Events - ma, 11/06/2018 - 02:00
The panel session highlights the future potential of fusion to “Lead the clean energy transition”

Water tanks to quench the thirst of ITER

F4E News - ma, 11/06/2018 - 02:00
F4E and Ensa deliver more equipment for the fuel cycle system of the biggest fusion device.

Join us at the Barcelona Energy Days Conference – 19 June 2018

F4E Events - do, 07/06/2018 - 02:00
The first edition of the Conference puts the focus on Energy Transition

Cryopump | Big cold trap under test

ITER - ma, 04/06/2018 - 21:07



Creating an ultra-high vacuum inside the vast toroidal chamber of the ITER Tokamak—the aptly named "vacuum vessel"—is imperative to initiating plasma operations.
Mechanical pumps will do the first part of the job, evacuating the air and most of the molecules from the 1,400 m³ vessel and reducing pressure to 1/10,000th that of the atmosphere (pressure is how vacuum is measured).
This, however, will not be sufficient. The quality of the vacuum needed on ITER is in the range of 1/10,000,000,000th that of the atmosphere, close to the deep-space void and impossible to achieve with a mechanical pumping system.
By chance, there is a simple law of physics that can take over when pumping machines reach their limits.
When a molecule or an atom encounters an extremely cold surface, it loses the best part of its energy and slows down to near immobility. This phenomenon is called "adsorption" and its intensity is proportional to surface temperature: the colder the surface, the more irresistible its holding power ...
A cryogenic pump—or cryopump for short—is based on this very principle. In ITER, there will be six torus cryopumps positioned around the vacuum vessel and entrusted with a double mission: perfecting the high vacuum inside the vacuum vessel prior to operation and evacuating helium ash, unburnt fuel and all exhaust gases during plasma shots. Another two cryopumps will be installed on the cryostat to provide the vacuum that thermally insulates the magnet system from the environment.
Every ITER cryopump is equipped with 28 "cryopanels" that will be cooled down to 4.5 K (minus 268.5 °C) by a flow of supercritical helium. These extremely cold surfaces will make an extremely effective particle trap.
The cryopanels (one metre long, 20 centimetres wide) are coated with a very fine, porous carbon matrix obtained from ground coconut-shell charcoal. Despite their relatively small size, they provide an immense surface for particles to stick to: if developed (flattened out), each carbon matrix would cover 5.5 square kilometres—an area close to 13 ITER platforms.
In August last year, a pre-production cryopump for the torus pumping system, built in collaboration by the ITER Organization and the European Domestic Agency, was delivered to the ITER site. The massive and highly sophisticated component is presently being tested in a laboratory that the ITER vacuum team has set up in the neighbouring CEA-Cadarache, close to the hall that hosts the WEST tokamak.
"No one has ever built a cryopump comparable to this one. It's absolutely unique and we have to familiarize ourselves with it," says Roberto Salemme, the ITER vacuum engineer who oversees the small team from the Air Liquide-40/30 consortium implementing the test program.
The valve inside the cryopump—the world's largest all-metal high vacuum valve—is one of the main focuses of the tests. Its head is 80 centimetres in diametre, weighs 80 kilos and travels along a 40-centimetre shaft stroke. When closing, it must lock with a precision of 0.1 millimetre to tighten its all-metal seal.
"We need to characterize the valve's mechanical properties and behaviour and precisely measure the forces that need to be exerted to move it along the shaft and obtain the required sealing at both atmospheric pressure and under vacuum," explains Roberto.
Once installed in the ITER machine, the cryopump will connect directly to the vacuum vessel. In order to mimic this configuration in the lab, the pump has been equipped with a dome that seals its open end and allows the creation of a vacuum inside—not ITER-grade, but sufficient to characterize the mechanical operation of the valve in "real" conditions.
There is a lot that still needs to be explored, measured and characterized before the cryopumps can enter series fabrication, and tests under cryogenic conditions will be essential to establishing the detailed succession of ITER operational sequences.
All that can be done in advance—like the ongoing tests at the ITER lab at CEA— will simplify the commissioning to be performed by the vacuum team for First Plasma and beyond.

 

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