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You're currently reading the news digest published from 2 May 2016 to 9 May 2016.
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Featured
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Teamwork in action: ITER diagnostics and electromagnetic design

ITER diagnostic systems will be vital in controlling the plasma as well as evaluating and optimizing machine performance. Required to "see" the plasma from many different angles, diagnostics will be installed in different locations around the vacuum vessel, integrated in port structures called "port plugs." Port plugs are massive components—up to 50 metric tons each—that seal the vacuum vessel port openings during operation and that will provide shielded housing, as well as a front-row seat, for instruments. At least 22 of ITER's 33 port plugs will be customized to house diagnostics.Since 2010, work has been underway on the engineering and port integration of ITER diagnostics based on a "generic" design that, for the moment, excludes the specificities of individual diagnostics to concentrate on methodology and technology. Carried out in collaboration with a team from the Princeton Plasma Physics Laboratory (PPPL), the work has focused on the generic design of equatorial and upper diagnostic port plugs, taking into consideration the design of the port cell infrastructure, interspaces and support structures as well as auxiliary components like windows and services such as cables and feedthroughs. Julio Guirao, from the ITER Common Port Plug Engineering team, and Yuhu Zhai, from the Princeton Plasma Physics Laboratory (PPPL), are working together to coordinate the effort toward a common component design that meets the challenging requirements for ITER diagnostics. They are pictured here at PPPL in front of coils from NCTX (the stellarator experiment that was cancelled in 2008). The major driver for the structural design of the generic equatorial and upper port plugs has been the need for the port plugs to withstand disruption forces and plasma vertical displacement events (a sudden vertical displacement of the plasma that can lead to extremely heavy loads). Although of extremely short duration—on the order of a few tens of milliseconds—they would induce large electromagnetic loads on the structural components of the port plugs.Consider the case of a Formula 1 race car. During normal operation the forces are fairly low, but inertial loads become a big factor when the car stops abruptly—in hitting a car or a barrier, for example. By design, it needs to resist the different types of forces it will encounter on the circuit, and to protect its payload and maintain its integrity. In ITER, the equivalent of an abrupt stop comes from rapid changes in the magnetic fields.  To study and predict these electromagnetic loads, and inertial effects, a joint ITER-PPPL team has come together to develop efficient and cost-effective electromagnetic (EM) analysis models able to handle interfacing actions. The team has also developed a critical electromagnetic data mapping procedure to integrate electromagnetic analysis with the structural analysis that defined load specifications for the generic plug and first-wall designs. This will ensure the structural integrity, and sound dynamic behaviour, of the diagnostic infrastructure for integration into the port. This is no simple task as the conventional approach to performing independent neutronic, electromagnetic, thermal-hydraulic and structural dynamic analysis alone isn't able to meet the full challenge of ITER diagnostics' engineering design and port integration. Highly innovative, multi-scale simulation solutions are required to take into account the full complexity of the engineering design, including the diagnostic apertures at the plasma-end of the port plugs. Members of the joint ITER-PPPL team for diagnostic port plugs: Wenping Wang, Andrei Khodak, Julio Guirao, Yuhu Zhai, Jingping Chen (front); Irving Zatz, Doug Loesser (back). A multi-physics engineering analysis protocol—with CAD design models integrated into state-of-the-art analysis tools—has been developed and implemented as a baseline methodology established for the port plug structure and first wall design. As a result, the ITER design can be cost effective, consistent and soundly justified through analysis.So how has all this gone lately? The generic equatorial and upper port plug structures and diagnostic first walls successfully passed a number of design review phases between 2011 and 2014. Design workshops were held last year for the diagnostic shielding module and, in January, an electromagnetic analysis workshop was successfully held for the diagnostic port plugs and in-port diagnostics. Julio Guirao, from the ITER Common Port Plug Engineering team, and Yuhu Zhai, from the Princeton Plasma Physics Laboratory (PPPL), work in close association to coordinate the effort toward a common component design that meets the challenging requirements for ITER diagnostics. "The EM workshop helped us to have a better understanding of the design driving electromagnetic disruption loads. We can now move forward in full speed for component design and port integration." Collaboration will continue between the ITER Organization Common Port Plug Engineering team and PPPL on the design of the diagnostic first wall and the diagnostic shielding module.  
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A new series of aerial photographs

Construction progress is clearly visible in this new series of aerial pictures, taken from a height of approximately 1,000 m on Friday 29 April by ultralight aircraft. The photographer passed over the site at around 6:30 p.m. (which explains the small number of vehicles in the main ITER parking lot). The most striking feature of the 42-hectare worksite is undeniably the Assembly Hall, whose mirror-clad surfaces reflect the changing hues of the surrounding landscape â€” just like the architects intended.   (Photo: MatthieuColin.com)   View more aerial pictures in the gallery below.
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A celebration for the commissioning of IFMIF elements

With the arrival of major accelerator components from Europe, a new commissioning phase has begun for the prototype accelerator LIPAc, part of the International Fusion Materials Irradiation Facility (IFMIF) that is currently in its engineering validation and design phase in Rokkasho, Japan. IFMIF is an accelerator-based neutron source that will use deuterium-lithium nuclear reactions to produce a large neutron flux similar to that expected at the first wall of a fusion reactor.  By testing materials under conditions similar to those expected in a future fusion power plant, IFMIF will help qualify the advanced materials that will be used for plasma-facing surfaces.  IFMIF's accelerator, LIPAc (the Linear IFMIF Prototype Accelerator) is designed to run a deuteron beam of 125 mA at 9 MeV in a continuous wave, reaching 1.1 MW beam power. The radiofrequency quadrupole and injector in position in Rokkasho, Japan. At a recent ceremony in Rokkasho, participants celebrated the commissioning of the accelerator's injector as well as the first phase of installation for the radiofrequency quadrupole and power generator. These milestones represent a step forward in design validation.In the next steps, the injector will undergo further upgrades and preparation activities for beam commissioning will continue. The main contributors to this important test facility are CEA (France), CIEMAT (Spain), INFN (Italy) and SCK-CEN (Belgium). IFMIF is one of three fusion energy research projects underway within the framework of the Broader Approach Agreement signed in 2007 between Europe and Japan. Read reports of the ceremony on the European Domestic Agency website and the IFMIF/EVEDA website. More on the IFMIF project at IFMIF.org.
Of interest

Improving predictions of the "bootstrap current"

https://www.iter.org/of-interest?id=599
Researchers at the US Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) have challenged the understanding of a key element in fusion plasmas. At issue has been an accurate prediction of the size of the "bootstrap current"—a self-generating electric current—and an understanding of what carries the current at the edge of plasmas in doughnut-shaped facilities called tokamaks. This bootstrap-generated current combines with the current in the core of the plasma to produce a magnetic field to hold the hot gas together during experiments, and can produce stability at the edge of the plasma. The recent work, published in the April issue of the journal Physics of Plasmas, focuses on the region at the edge in which the temperature and density drop off sharply. In this steep gradient region—or pedestal—the bootstrap current is large, enhancing the confining magnetic field but also triggering instability in some conditions. The bootstrap current appears in a plasma when the pressure is raised. [...] Physics understanding and accurate prediction of the size of the current at the edge of the plasma is essential for predicting its effect on instabilities that can diminish the performance of fusion reactors. --Illustration: Simulation shows trapped electrons at left and passing electron at right that are carried in the bootstrap current of a tokamak. Credit: Kwan Liu-Ma, University of California, Davis. Read the full article on the PPPL website.

India delivers power supply components to testbed

https://www.iter.org/of-interest?id=598
Another shipment of in-kind components from India has arrived at the PRIMA neutral beam test facility in Padua, Italy. At PRIMA, ITER's most powerful heating system—neutral beam injection—will be tested in advance of operation.  The SPIDER test bed is a 1:1-scale ion source that will be used to develop the technology for the production of negative ions. India already delivered the beam dump in late 2014; this time, 13 trucks carried the components of the 100 kV power supply. Read more about the lastest shipment here.

Journal "Nature Physics" produces an Insight on nuclear fusion

https://www.iter.org/of-interest?id=597
In its May 2016 issue, Nature Physics has produced an Insight on Nuclear Fusion that features an interview with ITER Director-General Bernard Bigot, a commentary by Steven Cowley (current Chief Executive Officer of the UK Atomic Energy Agency and Head of the EURATOM/CCFE Fusion Association), and a review of the fascinating physics that lies at the heart of nuclear fusion. A full list of content is available at this link. (Content may be accessed through a subscription to Nature Physics or rental/purchase.)  

Human-robot teams to operate inside fusion device

https://www.iter.org/of-interest?id=600
Watch humans and robots work together inside the JET mockup at the Culham Centre for Fusion Energy (CCFE) in the UK. Video via Tom Scott/CCFE
Press

꿈의 청정 에너지... 프랑스에 18兆 '인공 태양' 뜬다

http://m.chosun.com/svc/article.html?sname=news&contid=2016050700305

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