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Procurement activities for °ÄÃÅÁùºÏ²Ê¸ßÊÖ's poloidal field converters took a step forward in early February, as the long-duration, steady-state operation testing of the poloidal field AC/DC converter unit prototype was successfully carried out at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). China is responsible for procuring the 14 poloidal field converters that will provide controllable current/voltage to °ÄÃÅÁùºÏ²Ê¸ßÊÖ's six poloidal field coils.   The long duration steady-state operation test of the poloidal field converter unit—with rated continuous current, voltage and four-quadrant operation—was launched on 5 February and lasted three days and three nights (approximately 72 hours). As expected, the prototype demonstrated good stability and reliable performance throughout the test.   The 72-hour testing was important for unearthing potential problems and risks for the different subsystems during the steady-state operation of the poloidal field converter unit.   The success of the steady-state operation test will provide the data for the manufacture readiness review as well as experience for future batch production.

The PISCES-B device, located at the University of California San Diego (US), is a linear plasma test stand whose mission is to examine plasma-materials interactions for °ÄÃÅÁùºÏ²Ê¸ßÊÖ and future DEMO devices.   In late 2014, PISCES-B was used for a series of high-fluence plasma exposures to investigate the deuterium fuel retention properties of tungsten when exposed to continuous plasma bombardment. The goal was to determine whether the fuel retention in the tungsten saturates with fluence, or continues to increase as a function of the plasma exposure time.   The deuterium particle fluence was varied by almost three orders of magnitude with the maximum deuterium atom fluence being 2 × 1028 m-2. To achieve the maximum fluence exposure, the PISCES-B device was run continuously for over 30 hours, reaching a fluence equivalent to 50 full-power 400-second °ÄÃÅÁùºÏ²Ê¸ßÊÖ deuterium-tritium plasma pulses.   The experiment demonstrates the ability of linear plasma devices to operate in true steady state and to provide a test platform which can replicate plasma-material interaction conditions relevant to future DEMO reactors.   During pure deuterium plasma exposure, retention results indicate that saturation is not reached and that retention scales as the square root of time, indicative of diffusion dominating the fuel uptake of the tungsten.   The retention measurements are plotted in the graph at right against the database contained in an MIT report (#PSFC/RR-10-4) which addresses this issue. Also evident in the plot is that the high plasma flux achievable in PISCES-B (1.5 × 1023 m-2s-1) results in a lower level of retention, compared to the data contained in the MIT report which were collected under lower flux conditions.   However, measurements performed while sculpting the PISCES plasma to replicate a burning plasma, by adding a small amount (5 percent) of helium to the incident deuterium plasma, indicate the deuterium uptake in the target is severely inhibited. The diffusion barrier provided naturally by the helium ash contained in a burning plasma could alleviate many tritium-related concerns in future fusion reactors with tungsten plasma-facing materials.

Inaugurated last November, the 5,500-square-metre Cryostat Workshop will not remain empty for long. Later this year, in mid-September, the first batch of the 54 segments of the °ÄÃÅÁùºÏ²Ê¸ßÊÖ cryostat (the huge vacuum chamber that insulates the superconducting magnets of the machine) will leave the Larsen & Toubro factory in Hazira, India, to be delivered to the °ÄÃÅÁùºÏ²Ê¸ßÊÖ site for welding and assembly.   This first shipment will consist of the six 60-degree segments that form the first tier of the cryostat base section. The base section is one of four main sections (along with lower cylinder, upper cylinder and top lid) of the 30-metre-tall, 30 metre in diameter component. The cryostat base section—1,250 tonnes—is the single largest load of °ÄÃÅÁùºÏ²Ê¸ßÊÖ Tokamak assembly. It will also be the first component to be installed in the Tokamak Pit when assembly begins.   In April 2013, a first Manufacturing Readiness Review was held for the base section and lower cylinder segments. It was complemented by a second review on 30 January this year for the remaining items, namely the upper cylinder, top lid, shielding blocks, assembly tooling, transporter frames, etc.   "A Manufacturing Readiness Review consists in a complete review of documents, from drawings to manufacturing guidelines, that ensures that every production step has been carefully observed," explains Igor Sekachev, the engineer in charge of the cryostat at °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, who participated in the review along with representatives of °ÄÃÅÁùºÏ²Ê¸ßÊÖ India and contractor Larsen & Toubro.   Chaired by S.C. Chetal, former head of the Indira Gandhi Centre for Atomic Research (IGCAR), the panel also assessed the ongoing fabrication of the base section and lower cylinder at the shop floor.   "All in all, and as a result of the intense collaborative efforts between the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, °ÄÃÅÁùºÏ²Ê¸ßÊÖ India and Larsen & Toubro," adds Igor, "everything appears to be beautifully prepared and we gave our green light for the remainder of the manufacturing."   On-hold items are very few, principally interfacing components that haven't yet reached a sufficient level of maturity.   This is the case for the tokamak cooling water system, the large rectangular bellows, the circular bellows for the neutral beam injectors, and the housings for the torus cryopumps. "We're all working hard to bring these components to final design in order to release the on-hold items as soon as possible."   With Dilshad Sulaiman, °ÄÃÅÁùºÏ²Ê¸ßÊÖ India   Chaired by S.C. Chetal, the review panel consisted of representatives from °ÄÃÅÁùºÏ²Ê¸ßÊÖ India and °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, including: Igor Sekachev, Cryostat Section Leader at °ÄÃÅÁùºÏ²Ê¸ßÊÖ; Anil Bhardwaj, Cryostat Project Manager at °ÄÃÅÁùºÏ²Ê¸ßÊÖ India; M.K. Dipak, Expert from the Nuclear Power Corporation of India Ltd. (NPCIL); Girish Gupta, °ÄÃÅÁùºÏ²Ê¸ßÊÖ India Cryostat Technical Responsible Officer;  Rajnikant Prajapati, °ÄÃÅÁùºÏ²Ê¸ßÊÖ India Cryostat Quality Assurance Responsible Officer; and Dilshad Sulaiman, °ÄÃÅÁùºÏ²Ê¸ßÊÖ India Project Office & Communication Responsible Officer.   Participants from Larsen & Toubro Ltd. were led by Ganesh Iyer (Cryostat Project Head) and Pandurang Jadhav (Cryostat Project Design Head).

A few years before °ÄÃÅÁùºÏ²Ê¸ßÊÖ is due to come into operation, the advanced superconducting "satellite" tokamak JT-60SA, conducted under the Broader Approach Agreement between Japan and Europe, will begin operation.  Another milestone on the road to JT-60SA assembly was achieved in February, as six European-built helium pressure vessels—destined for JT-60SA's cryogenic system—successfully passed final works acceptance tests and can now be readied for shipment to Japan. The acceptance tests, which consisted of verifications to ensure that the components conform to international standards and to ensure that there are no defects, was carried out during a period of seven days each. In total, the six pressure vessels will store 3.6 tons of gaseous helium. Each 22-metre pressure vessel weighs about 73 tons, and has a diameter of 4 metres and a volume of 250 m3. As the vessels will store pure helium, the tightness and cleanliness requirements are demanding. If a fast discharge of the current in the superconducting coils is necessary, one of the vessels is also designed to receive cold helium (-254 degrees C) discharged from the coils through the cryogenic system quench line. The contract for the supply and transport to Japan of the pressure vessels and their equipment was awarded by the European Domestic Agency to A. Silva Matos Metalomecanica SA (ASMM, Portugal). Read the full article on the European Domestic Agency website.  

​Knowledge is not cheap. The world spends more than $1 trillion a year on research and development, including basic research. The biggest projects—"research infrastructures" like particle accelerators and DNA databases—carry correspondingly big price tags. °ÄÃÅÁùºÏ²Ê¸ßÊÖ, the experimental, international fusion reactor in the south of France, is taking years and more than EUR 13 billion to build. The Square Kilometre Array, the world's biggest radio telescope now under development in South Africa and other southern countries, will cost well more than EUR 1.5 billion   It's all great science, no doubt. But is it a great investment?     Read the full report from Science|Business, prefaced by Rolf Heuer, Director-General, CERN.

​Culham Centre for Fusion Energy (CCFE) is one of the partners in a materials research project that has recently been awarded significant European funding. The project will explore techniques that can accurately examine engineering components at a range of sizes and scales — right down to the nanoscale analysis carried out in Culham's Materials Research Laboratory (MRL). To get a consistent picture of the properties of a material, researchers need to examine it at different length scales. This new study will look at how changing the specimen size or the size of the probe used for testing affects the measured engineering properties. Test methods or design rules can then be developed that compensate for such 'size effects.' It is hoped that European companies can use the results to design and manufacture better components with longer life and lower energy use. The work will also benefit the fusion and fission research sectors, where smaller samples represent less of a safety risk when examining the condition of components. Led by the National Physical Laboratory, the project consortium brings together major industry players such as EDF, AMEC, AWE and Tata Steel with universities and research institutes around Europe. The grant of ~EUR 1.8 million has been made by European Association of National Metrology Institutes (EURAMET). Read more on the CCFE website.