Construction of Wendelstein 7-X - Engineering a steady state stellarator

Werner, V.; König,; Stadler, Konstantin; Erckmann,; Schauer,

doi:10.1109/fusion.2009.5226367

Cited by 10 publications

(11 citation statements)

References 19 publications

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“…We can see how the (m, k) = (1, 6) is the dominant mode of the linear phase with smaller contributions from the (m, k) = (−1, 4) and (m, k) = (−1, 5) modes. The modes (1,8) and (1,11) are also present but with even smaller contributions. .…”

Section: 8mentioning

confidence: 99%

“…Constructing the structured meshes for the geometries considered in EVA is not a difficult task, even in the case of unorthodox domains like the vacuum vessels of the most important experiments in the magnetically confined fusion community today: ITER (See [69,102,68,98,4,47]) and the W7-X (See [26,109,88,110,8,67,112] ) since they are found in their corresponding VMEC-solution files. Finding the values at the nodes however, requires some sort of interpolation technique.…”

Section: Data Visualizationmentioning

confidence: 99%

“…The runs begin with N 0 = 101 in the initial stage 8 , and 303 in the final stage. The results are summarized in fig.…”

Section: Impact Of the Parameter ∆ On Convergencementioning

confidence: 99%

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Magneto-hydrodynamical nonlinear simulations of magnetically confined plasmas using smooth particle hydrodynamics (SPH)

et al. 2019

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Finally I would like to thank Milena Plazinic for her constant support, her love, her patience and her dedication. I might know a thing or two about physics, but when it comes to life you are my guide, my light and my strength. I love you.xii Published and Submitted ContentArticles or other contributions (co)-authored by the Doctoral candidate that are included as part of the thesis and that have been published:

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Section: 8mentioning

confidence: 99%

Section: Data Visualizationmentioning

confidence: 99%

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Magneto-hydrodynamical nonlinear simulations of magnetically confined plasmas using smooth particle hydrodynamics (SPH)

et al. 2019

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“…In this investigation we try to quantify the related properties of a penetrant dye used during the assembly of the advanced stellarator Wendelstein 7-X [1]. The possible blocking of leaks by the PT medium was not investigated, because at the W7-X all PT tested vacuum boundary welds are leak tested before the PT application.…”

Section: Introductionmentioning

confidence: 99%

On the applicability of dye penetrant tests on vacuum components: Allowed or forbidden?

Schröder¹,

Biedermann²,

Vilbrandt³

2013

Fusion Engineering and Design

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The penetrant testing (PT) is a common non-destructive procedure for the testing of components and in particular of welds. With PT it is possible to detect surface imperfections (e.g. cracks) which have a special potential to lead to the failure of the component or of the weld. PT is substantially more sensitive than a purely visual examination.Because the complicated geometries of fusion experiments make the accessibility for repairs during the operation extremely difficult, very high efforts on testing with sensitive procedures, for instance with dye penetrant testing during assembly is required. In contrast to this desire for widespread penetrant testing, however, is the general fear that dye penetrant tested components or welds, which are used in the vacuum, are contaminated by the dye in such a way that they do not fulfill the cleanliness requirements for vacuum components. Therefore dye penetrant testing of such vacuum components is usually considered problematic.This study aims to clarify the applicability of dye penetrant tests on components exposed to high-vacuum. Recommendations are formulated concerning the PT procedure of vacuum components and the cleaning procedures for penetrant tested areas under vacuum necessary after a dye penetrant test.Keywords: dye penetrant testing, vacuum component, UHV, NDT BackgroundFusion experiments are complex equipments with often complicated geometry. It is desirable to operate the machines over long time periods without shut-down interruptions for repair or service. If there are interruptions of the regular experiment operation, the search for failures and the repair will be very difficult and extensive in time and costs. To avoid these kinds of breakdowns, a strong effort on quality control is necessary like e. g. non-destructive testing procedures during the manufacturing of components and its assembly. Beside the visual examination (VT), the method of penetrant testing (PT) is often most common non-destructive procedure for the testing of surfaces of components and in particular of welds.In contrast to this desire for widespread penetrant testing, however, there is the general fear that components or welds tested with the dye penetrant and which are used in the environment of cryo-vacuum and particularly in the ultra-high vacuum conditions are contaminated by the dye in such a way that they do not fulfill the cleanliness requirements for vacuum components. This fear is mainly based on the high penetrating property of the dye and its particular creeping characteristics, which just is the property required for the test procedure. After the penetration test, however, the penetrant dye may remain in cavities like porosities or in cracks and might cause virtual leaks during the evacuation and in the vacuum, due to extended outgassing. As the penetrant dye primarily consists of hydrocarbons, which are considered critical for outgassing in fusion devices, a penetrant test of such vacuum components is usually considered problematic.In this investigation we try to quantif...

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“…The first three modules of the magnet system (out of 5) have been successfully completed within schedule and are already installed in the torus hall [2,3].…”

Section: Introductionmentioning

confidence: 99%

Structural analysis of W7-X: From design to assembly and operation

Bykov

Schauer

Egorov

et al. 2011

Fusion Engineering and Design

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Abstract-The Wendelstein 7-X (W7-X) modular stellarator is in the assembly phase at the Max-Planck-Institut für Plasmaphysik in Greifswald, Germany. The design of the "basic machine", i.e. without in-vessel components, diagnostics and periphery, is largely completed, structural parameters such as bolt preload, initial conditions for contact elements, etc. are defined, and most of the components are manufactured and partly assembled. Therefore, the focus of structural analysis was shifted towards fast analyses of nonconformities, changes in the assembly procedure, and exploration of operational limits. Assembly-related work is expected to continue until commissioning of the machine, however, with decreasing intensity. In parallel the analysis requirements for in-vessel components, diagnostics and periphery will increase. This paper focuses on the most remarkable results, on special problems which had to be solved, on strategic issues like parameterization, complex finite element model structuring and benchmarking with alternative models in different codes, on assumptions of reasonable safety margins and expected tolerances, and on confirmation of analysis results by tests. Finally it highlights some lessons learned so far, which might be relevant also for other large fusion machines, and gives an outlook on future work.

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Construction of Wendelstein 7-X - Engineering a steady state stellarator

Cited by 10 publications

References 19 publications

Magneto-hydrodynamical nonlinear simulations of magnetically confined plasmas using smooth particle hydrodynamics (SPH)

Magneto-hydrodynamical nonlinear simulations of magnetically confined plasmas using smooth particle hydrodynamics (SPH)

On the applicability of dye penetrant tests on vacuum components: Allowed or forbidden?

Structural analysis of W7-X: From design to assembly and operation

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