The DOE SC program in Fusion Energy Sciences (FES) hereby announces its interest in receiving applications to carry out experimental research in magnetic fusion energy sciences on long-pulse overseas stellarator facilities, namely, Wendelstein 7-X (Germany) and the Large Helical Device (LHD – Japan).

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The research should be related to the planning, execution, and analysis of experiments concerning the topical areas described below.

The FES Burning Plasma Science:
Long Pulse portfolio supports U.

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researchers who work in collaboration with foreign scientists to explore critical science and technology issues at the frontiers of magnetic fusion research.

These collaborations take advantage of the unique capabilities of the most advanced overseas research facilities.The National Academies of Sciences, Engineering, and Medicine released a report recommending that the U.

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start a national program of accompanying research and technology leading to the construction of a compact pilot plant that produces electricity from fusion at the lowest possible capital cost.

In addition, the Division of Plasma Physics of the American Physical Society (APS/DPP) conducted a community planning process (CPP) that identified the stellarator as a potential path to a fusion pilot plant.

The APS/DPP CPP also recommended international collaboration as an important avenue for advancing the stellarator so that it can be considered for this goal.

Grant Applications should describe how the proposed research advances the stellarator towards these goals.The 2016 SC document, entitled:
“Fusion Energy Sciences Program:
A Ten-Year Perspective,” calls for leveraging of mature U.

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research knowledge into collaborative research activities carried out on long-pulse overseas facilities with superconducting magnets.

The U.

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has made numerous investments in both machine components and diagnostics for Wendelstein 7-X (W7X), with emphases on (1) edge and divertor research and (2) understanding and enhancement of core confinement.

This FOA seeks to continue the major U.

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collaboration on W7-X, and to pursue opportunities to advance 3D confinement understanding through targeted collaborations with the world’s other large superconducting stellarator, LHD.

Grant applications in response to this FOA must be relevant to the research priorities of W7-X and LHD in the next three years namely:
1.

Understanding compatible core-edge solutions:
W7-X, which uses an island divertor concept, is in the process of upgrading the divertors and plasma-facing components to be compatible with long-pulse operation.

Grant applications aimed at understanding and optimizing the use of this new capability are sought.

LHD is testing a closed helical divertor.

Research that supports the development of validated physics models for 3D divertors is sought.

2.

Understanding limits:
Results from the initial operation of W7-X have identified regimes with improved ion confinement.

Grant applications aimed at controlling and utilizing, as well as characterizing and expanding, these new regimes are of interest.

The W7-X plasma-divertor interface can be affected by bootstrap currents and field errors.

Research to understand and control these effects is sought.

3.

Exploiting U.

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hardware investments:
The U.

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will install a new steady-state pellet injector system on W7-X to support long-pulse operation.

The U.

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has also invested in the scientific capabilities of W7-X, including trim coils for low-order field error control, a divertor “scraper element,” infrared and visible imaging, an x-ray imaging crystal spectrometer diagnostic, fluctuation diagnostics, and neutral pressure measurements.

Research is sought that complements U.

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stellarator research activities, e.g., in operational scenario development, data analysis, or modeling on the important topics of MHD and 3D magnetic structure, boundary and scrape-off-layer physics, and neoclassical and turbulent transport.

4.

Long-pulse, high power operation:
As the now-upgraded W7-X begins long-pulse operation at full heating power, additional issues arise in the area of core fueling and heat flux management and control.

Research that enables successful high-power, long-pulse operation is sought.

5.

Comparative studies on long-pulse helical devices:
LHD and W7-X have substantially different designs.

Numerous opportunities exist to understand the physics of helical confinement devices by comparative studies.

Research that exploits these opportunities is sought.

Research on W7-X will be carried out within the framework of the Project Agreement between the Max Planck Institute for Plasma Physics (IPP) and DOE for collaboration in W7-X research.

Research on LHD will be performed under the auspices of the International Energy Agency Stellarator Heliotron Technology Collaboration Program.

In addition, institutions without existing agreements with the National Institute for Fusion Science (NIFS) in Japan, will have to set up individual task agreements.

Applications for W7-X and LHD research must include letters of support for the proposed collaborative effort from the host institutions:
IPP for W7-X and NIFS for LHD.