Review of the high heat flux testing as an integrated part of W7-X divertor development

Greuner, H.; Böswirth, B.; Boscary, J.; Friedrich, T.; Lavergne, C.; Linsmeier, Ch.; Schlösser, J.; Wiltner, A.

doi:10.1016/j.fusengdes.2008.12.083

Cited by 23 publications

(15 citation statements)

References 8 publications

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“…Secondly, load case 2 where in addition all rotational degrees of freedom were released for the fixation areas (A), (B), (C) and (D). The thermal calculation shows that the maximum temperatures of the CFC tiles, interlayers and CuCrZr heat sinks are 911 °C, 481 °C and 321 °C, respectively, which correspond to the experimental results [11]. The temperatures of the other components are lower than 70 °C.…”

Section: *Manuscript Click Here To View Linked Referencessupporting

confidence: 80%

Thermo-mechanical analysis of Wendelstein 7-X plasma facing components

Peng

Bykov

Köppen

et al. 2013

Fusion Engineering and Design

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The stellarator experiment Wendelstein 7-X (W7-X) is designed for stationary plasma operation (30 minutes). Plasma facing components (PFCs) such as the divertor targets, baffles, heat shields and wall panels are being installed in the plasma vessel (PV) in order to protect it and other invessel components. The different PFCs will be exposed to different magnitude of heat loads in the range of 100 kW/m2 to 10 MW/m2 during plasma operation. An important issue concerning the design of these PFCs is the thermo-mechanical analysis to verify their suitability for the specified operation phases. A series of finite element (FE) simulations has been performed to achieve this goal. Previous studies focused on the test divertor unit (TDU) and high heat flux (HHF) target elements. The paper presents detailed FE thermo-mechanical analyses of a prototype HHF target module, baffles, heat shields and wall panels, as well as benchmarking against tests. Xuebing PengMr.Max Planck Institute for Plasma Physics, EURATOM Association,Greifswald, Germany 14 September 2012 Dear Dr. Ing.Olaf, Please accept the attached manuscript of the paper, named Thermo-mechanical analysis of Wendelstein 7-X plasma facing components, for SOFT-27 special issue. The paper is about the thermo-mechanical analysis of Wendelstein 7-X plasma facing components, including the high heat flux divertor targets, baffles, heat shields and wall panels, in order to verify their suitability for steady state operation.I greatly appreciate you taking time to read this letter and the paper, and am look forward to hearing from you. Best regardsSincerely yours, Xuebing Peng. Cover Letter Research Highlights Thermo-mechanical analysis of HHF divertor module TM-H09 shows that it can withstand heat loads of 10 MW/m 2 in steady state when the supports was optimized accordingly.  FE calculations indicate that the tiles of baffles and heat shields can withstand stationary heat loads of 250 kW/m 2 , but that the pulse length of plasma operation must be limited depending on the number of full load (500 kW/m 2 ) cycles.  Gap requirements for wall panels during assembly were defined based on several FE calculations. The stellarator experiment Wendelstein 7-X (W7-X) is designed for stationary plasma operation (30 minutes). Plasma facing components (PFCs) such as the divertor targets, baffles, heat shields and wall panels are being installed in the plasma vessel (PV) in order to protect it and other in-vessel components. The different PFCs will be exposed to different magnitude of heat loads in the range of 100 kW/m 2 to 10 MW/m 2 during plasma operation. An important issue concerning the design of these PFCs is the thermo-mechanical analysis to verify their suitability for the specified operation phases. A series of finite element (FE) simulations has been performed to achieve this goal. Previous studies focused on the test divertor unit (TDU) and high heat flux (HHF) target elements. The paper presents detailed FE thermo-mechanical analyses of a prototype HHF target modu...

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Section: *Manuscript Click Here To View Linked Referencessupporting

confidence: 80%

Thermo-mechanical analysis of Wendelstein 7-X plasma facing components

Peng

Bykov

Köppen

et al. 2013

Fusion Engineering and Design

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“…The elemental carbon in the CFC is represented by the two dominating peaks above 284 and 285 eV. The carbide is formed already during the bonding process, as could be shown earlier in the comparison of an unloaded W7-X target element with an element after extended high heat loading [4].…”

Section: Chemical State Of the Interface Elements: Xps Resultsmentioning

confidence: 55%

Micro-chemical analysis of high heat loaded CFC–Cu interfaces from Tore Supra and Wendelstein 7-X

et al. 2011

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A comparison of high heat flux (HHF) tested CFC/Cu materials of Tore Supra and Wendelstein 7-X plasma-facing components is performed in order to understand the different fatigue behavior of the bonding interface, in particular for the Tore Supra materials. The elemental distribution around the bonding layer and the chemical composition of the active element titanium are characterized by secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS). The results show that the improved bonding of the Wendelstein 7-X target elements compared to the Tore Supra pump limiter elements is due to a modified silicon and titanium distribution at the bonding interface. However, the difference of the fatigue behavior between the two Tore supra components cannot be attributed to the bonding interface, since the elemental distribution and chemistry for these components are identical and no degradation is observed after extended heat flux exposure. IntroductionFor the toroidal pump limiter (TPL) elements of Tore Supra (TS), two different qualities of carbon-fiber reinforced carbon (CFC) material, produced by SNECMA, were applied [1]. While SEP N11-92 (produced in 1992) was within the specifications, the N11-98 (produced in 1998) showed a slight deviation in its mechanical properties. Small differences in the percentage range were measured for the density, tensile and shear stress [6]. After both batches were finally accepted for production, the so-called "TS finger elements" equipped with N11-98 tiles showed a much higher failure rate and degraded performance. For Wendelstein 7-X (W7-X), a similar but further developed CFC material (NB31) from the same manufacturer is used at the target elements. Critical to the target elements is the bonding between the CFC as plasma-facing material and the Cu-based heat sink structure. Over the years, the active metal casting (AMC) process and the laser structuring of the CFC material have been optimized by PLANSEE SE. The advanced AMC is based on a Ti alloy with an addition of Si [5] acting as bond between the CFC and Cu structures.

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“…The successful HHF testing in the GLADIS [8] facility (10 MW/m² loading up to 10,000 cycles, 16 MW/m² cycling and screening tests up to 32 MW/m²) confirmed the robustness of the design, the manufacturing route, the process control methods and in particular the applied CFC/Cu bonding technology [9,10]. The achieved agreement in the assessment results of the PLANSEE pulsed thermography facility ARGUS [9] and the HHF test results were an important step and essential for the clearance of the series production [7].…”

Section: Strategy Of Testing Of the Series Elementsmentioning

confidence: 71%

Results and consequences of high heat flux testing as quality assessment of the Wendelstein 7-X divertor

Greuner

Toussaint

Böswirth

et al. 2013

Fusion Engineering and Design

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The series manufacturing of the first 282 Wendelstein 7-X divertor elements was concluded in 2011. The divertor is designed to remove a steady-state heat load of 10 MW/m². 940 target elements of five different types made of CuCrZr heat sinks and covered with 16,000 CFC NB31 flat-tiles have to be produced. Additional to quality assessment during the manufacturing process, a final assessment of the delivered elements with operational heat load is indispensable to ensure a constant high thermal performance of the installed divertor. Based on the results of the pre-series testing a statistical quality assessment method has been developed for the series production. The application of this method to the series elements ensures their thermal performance with reasonable high heat flux test effort.

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Review of the high heat flux testing as an integrated part of W7-X divertor development

Cited by 23 publications

References 8 publications

Thermo-mechanical analysis of Wendelstein 7-X plasma facing components

Thermo-mechanical analysis of Wendelstein 7-X plasma facing components

Micro-chemical analysis of high heat loaded CFC–Cu interfaces from Tore Supra and Wendelstein 7-X

Results and consequences of high heat flux testing as quality assessment of the Wendelstein 7-X divertor

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