After the signing of the Vacuum Vessel Procurement Arrangement by the ITER Organization on 7 October, the vacuum vessel group launched the Procurement Arrangement for in-wall shielding with a kick off meeting on Wednesday 22 October in the presence of Haresh Pathak from the Indian Domestic Agency.
The ITER vacuum vessel is a double-wall box structure, with a space between the inner and outer shells that is filled with pre-assembled or modular blocks. These blocks are called "in-wall shielding." There are two types of in-wall shielding: primary in-wall shielding provides effective neutron shielding, while ferromagnetic inserts provide neutron shielding and reduce the toroidal field ripple.
The Indian Domestic Agency is in charge of the procurement and delivery of more than 6,000 shielding blocks for installation into the vacuum vessel sectors being manufactured in Korea and Europe, while yet more blocks will be delivered to ITER for installation in the field joint regions when the vacuum vessel sectors are assembled in-pit. The weight of each neutron shielding plate can vary between 50 and 500 kg depending on its location.
The space between the inner and outer shells of the vacuum vessel is also used for cooling and so the in-wall shielding blocks will be exposed to water. Understandably there was concern regarding corrosion and the radiation levels of the cooling water. Other topics included interfaces with the in-wall shielding, electromagnetic loading, and ferromagnetic material distribution.
The deadline for the completion of the Procurement Arrangement is 20 November, followed by signature by the Indian Domestic Agency by the end of December 2008.
The winner of this year's "Nuclear Fusion Award" is T.E. Evans for the paper "Suppression of large edge localized modes with edge resonant magnetic fields in high confinement DIII-D plasmas" (Nuclear Fusion 45 595-607). The award was presented on 16 October 2008 at the 22nd IAEA Fusion Energy Conference in Geneva, Switzerland.
"This is a landmark experimental paper demonstrating the efficacy of using resonant magnetic field perturbations (RMPs) for the suppression of large amplitude edge localized modes (Type I ELMs); a critical issue for ITER and other reactor-grade machines because of the erosion of the divertor target that would occur if ELMs are not controlled," writes the publisher. "This demonstration of ELM suppression without a reduction in H-mode global confinement performance has stimulated much subsequent work in the field, both experimental and theoretical, and encouraged the proposal that a similar RMP coil set be included in the design for ITER. The experiment was based on the expectation that ergodization of the edge magnetic fields could reduce the pressure gradient that drives MHD instability to trigger ELMs. The paper examined the extent to which this is borne out by experiment and raised plasma physics issues which are currently subject to intense examination."
As a service to the nuclear fusion research community, the winning paper will be freely available to read until the end of March 2009 at http://www.iop.org/.
An ITER Organization-Domestic Agency workshop on HAZard and OPerability analysis (HAZOP) took place last week. Together with more that 15 representatives from all seven Domestic Agencies, the ITER tritium group and a consultant from the United States went through a first general presentation of the analysis that will be required for all ITER systems wetted by tritium. The HAZOP studies will help to define a safe system design and acceptance criteria for ITER equipment. The method will thus be used to help design all tritium loops within ITER. The two-day training was an initiative of US ITER together with the ITER tritium group. As a conclusion, the usefulness of this approach was recognized and the implementation plan discussed.
On 1 November 2008, Günther Hasinger is to take up his appointment as Scientific Director of Max Planck Institute of Plasma Physics (IPP) at Garching and Greifswald. He succeeds Alexander M. Bradshaw, who has headed IPP since 1999.
Click here to read the press release...
Even in the event of only a slight injury, you should immediately call the rescue team (CEA FLS), by dialing 18 (or 04 42 25 22 18—or by using the emergency call button). CEA FLS is authorized to look after injured people and to transport them to the Medical Centre; before the arrival of the FLS, the ITER First Aid Team is here to secure the area and carry out initial emergency actions.
An Indian-built launcher carrying a one-and-a-half-tonne satellite blasted off from Satish Dhawan Space Centre in Sriharikota, an island off the coast of Andhra Pradesh, at about 06:20 local time (00:50 GMT) last Wednesday 22 October.
One key objective is to search for surface or sub-surface water-ice on the Moon, especially at the poles.
Another is to detect helium 3, an isotope which is rare on Earth, but is sought to power nuclear fusion and could be a valuable source of energy in future.
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Although the ITER site still looks like a sandy plain with lots of machines working to level the platform, some people within the ITER Organization think ahead, way ahead ... about 10 years to be exact, when ITER will be up and running!
Didier van Houtte's primary responsibility, as Senior Project Coordinator for RAMI in the Project Office, is to make sure that all the systems of the ITER machine will be reliable during the operation phase and maintain their performance under operational conditions with the best possible availability.
The RAMI process, which is based on a functional analysis and a FMECA (Failure Mode Effects and Criticality Analysis) approach, aims to ensure that at all times, the ITER machine is
Reliable (continuity of correct operation) Available (readiness for correct operation)Maintainable (ability to undergo rapid repairs and modifications)Inspectable (ability to undergo easy visits and controls)
Failure of only one small function might result in the machine being halted for long periods of time and result in high costs for repairs and replacements. It is therefore important that every system undergoes a risk analysis to evaluate WHAT can go wrong, WHERE, and WHEN, and to recommend spare components, back-up systems, increased frequency maintenance schedules, systems design optimization etc., to reduce the risk of a main function breakdown to a minimum.
The RAMI approach allows small expenditure on a critical function failure, instead of large expenditure on a unreliable component of a not very important function, while achieving the same result in term of machine availability.
The analysis of all these systems must of course primarily be carried out in the design and procurement phase of the project to make sure RAMI requirements are taken into account when the systems and their critical spare parts are manufactured.
So these are busy times for Didier, soon to be assisted by additional staff for RAMI. He also works with contractors and Domestic Agencies on some of these specific issues.
Before coming to ITER, Didier worked for Tore Supra where he started in 1986, and was the Head of Operations for 10 years. "One of the fascinating parts of my job here is that I get to work in all the technical fields with all the departments and all the Domestic Agencies. I really enjoy having the opportunity to think ahead to failures that could occur during ITER operation, after having been constrained to do many repairs on certain subsystems of Tore Supra during their operation and construction, which gives me a very broad and interesting perspective on the future operation of the ITER machine."
Among the 2,100 papers submitted by the participants to the Second Atoms for Peace conference, held in Geneva in October 1958, was an article about the "Stability and Heating of Plasmas in Toroidal Chambers." The paper presented the results Soviet fusion scientists had achieved in an "experimental arrangement"—a small fusion machine which is generally considered to be the first tokamak in history. Nowhere in the article did the word "tokamak" appear, nor did the "arrangement," now referred to as T-1, have a name of its own.
"Experimenting with toroidal configurations started in the mid-1950s," remembers Vladimir Mukhovatov, now a Senior Scientific Officer with the ITER Organization, then a 23-year-old researcher freshly out of Moscow State University. "Our 'Sector-44' within the Laboratory of Measuring Apparatus of Academy of Science—the future Kurchatov Institute—was building machines at a very fast pace. When I arrived in 1956 for my graduation thesis, there was a small toroidal device called TMP, originally equipped with a porcelain chamber which was soon improved by adding metal spirals within the chamber. Later two small devices with copper walls and insulating gaps were built."
By "late 1957," according to Mukhovatov's recollection, these devices were succeeded by T-1 which was somewhat larger and marks the "symbolic beginning" of the tokamak adventure. T-1 was the first device to have a stainless steel liner inside a copper vacuum chamber.
Finding a name for this new toroidal concept was to take some time and quite a bit of discussion. "Igor Golovin, then vice-director of the laboratory, came up with an acronym: 'Tokamak' for Toroidalnaya Kamera i Magnitnaya Katushka (Toroidal Chamber and Magnetic Coil). A combination of "Tok" for electric current and "Mag" for magnetic field, with a connective vowel 'o', which gave "tokomag" or "tokomak" after replacing "G" with "K" for harmony, was also circulated..."
Whether it was 'Tokomag' or 'Tokamak' ... Lev Artsimovitch, head of Department of Plasma Research, was initially sceptical about the concept. Vladimir Mukhovatov remembers the man "liked to use strong, spectacular, sentences." "When engaging in polemics, he would say that 'achieving fusion with a tokamak was the same as trying to create a cigarette out of cigarette smoke.' It is only after experiments on T-2, TM-2 and especially T-3 that he became a strong proponent of tokamaks. And in a way, this led to ITER."
The sky of Haute-Provence has always been one of the purest, driest and most transparent in Europe. The area around Manosque and Forcalquier enjoys an average of 300 cloudless days a year—and about as many clear nights—which, besides making life very pleasant, is ideal for astronomical observations.
It was even more so in the late 1920s, when the French National Service for Scientific Research decided to create a new observatory to complement the one in Paris, where fog, urban lights and ground vibrations were making observations more and more difficult.
Site studies lasted for several years and in 1936, a wooded plateau close to the village of Saint-Michel, 12 km to the south-east of Forcalquier, was eventually chosen to host the installation.
For more than a half-century, by observing stars and comets, galaxies and asteroids the Observatoire de Haute-Provence (OHP) was to contribute to the understanding of the Universe.
But in the world of astronomy things were changing fast: new challenges required more powerful instruments, which, in turn, demanded ever more transparent skies and a stable atmosphere. Eight- or ten-metre mirrors were becoming the norm, positioned at ever higher altitudes. With its 1.93-metre telescope, peering at the stars from a hilltop a mere 600 metres high, the OHP, once among the leading observatories in Europe, was under threat.
By the mid 1990s, the place was scheduled to close. At this point, two astronomers from Observatoire de Genève, Switzerland, using a high performance spectrometer coupled to the old "193," made an historical discovery: a planet orbiting a distant star 48 light-years from Earth—the first proof that the solar system was not unique in the Universe.
The discovery of this "hot Jupiter" orbiting star 51 Pegasi was to be followed by scores of others. Searching for exoplanets is now one of the observatory's fields of excellence: more than 300 have been discovered to this day, some 30 of them at the OHP.
Needless to say, no one talks about closing the old Provencal observatory anymore.
Six staff members from the Norwegian computer software company Systor Vest AS, keen to learn about a technology they believe capable of saving us from fossil fuels, visited the ITER site on 23 October.
Researchers at the University of California, Los Angeles, have shown that simply peeling ordinary sticky tape in a vacuum can generate enough X-rays to take an image. The researchers suggest that the high charge density generated by peeling the tape could be great enough to trigger nuclear fusion.
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