A5059353821- Fusion materials and technologies
- Nuclear Materials and Properties
- Magnetic confinement fusion research
- Advanced materials and composites
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Metal and Thin Film Mechanics
- Superconducting Materials and Applications
- Additive Manufacturing Materials and Processes
- Nuclear Physics and Applications
- Advanced ceramic materials synthesis
- Particle accelerators and beam dynamics
- Intermetallics and Advanced Alloy Properties
- Microstructure and mechanical properties
- Advanced Materials Characterization Techniques
- High-Temperature Coating Behaviors
- Plasma Diagnostics and Applications
- Microstructure and Mechanical Properties of Steels
- Metal Alloys Wear and Properties
- Diamond and Carbon-based Materials Research
- Plant responses to water stress
- Numerical methods in engineering
- Soil Mechanics and Vehicle Dynamics
- High-pressure geophysics and materials
- Advanced Optical Sensing Technologies
Forschungszentrum Jülich
2013-2023
Japan External Trade Organization
2015
Since the ITER divertor design includes tungsten monoblocks in vertical target where heat loads are maximal, to protect leading edges as well technology R&D for high performance armor-heat sink joint were necessary be implemented. In R&D, availability of was demonstrated by flux test monoblock components. Not systematically but frequently macro-cracks appeared at middle after 20 MW/m2 loading. The initiation such considered due cyclic exposure temperature, ∼2000 °C, creep, recrystallization...
The interaction processes between the burning plasma and first wall in a fusion reactor are diverse: will be exposed to extreme thermal loads of up several tens megawatts per square meter during quasistationary operation, combined with repeated intense shocks (with energy densities megajoules pulse durations on millisecond time scale). In addition these loads, subjected bombardment by ions neutral particles (D, T, He) energetic neutrons energies 14 MeV. Hopefully, ITER not only demonstrate...
Plasma facing components in future thermonuclear fusion devices will be subjected to intense transient thermal loads due type I edge localized modes (ELMs), plasma disruptions, etc. To exclude irreversible damage the divertor targets, local energy deposition must remain below threshold for selected wall materials. For monolithic tungsten (pure and alloys) power densities above ≈0.3 GW m −2 with 1 ms duration result formation of a dense crack network. Thin coatings so-called ITER-like JET,...
In fusion reactors, surfaces of plasma facing components (PFCs) are exposed to high heat and particle flux. Tungsten Copper alloys primary candidates for materials (PFMs) coolant tube materials, respectively, mainly due thermal conductivity and, in the case tungsten, its melting point. this paper, recent understandings future issues on responses tungsten Cu environments (high flux (including T He), flux, neutron doses) reviewed. This review paper includes; Tritium retention (K. Schmid M....
The provision of a particle and power exhaust solution which is compatible with first-wall components edge-plasma conditions key area present-day fusion research mandatory for successful operation ITER DEMO. work package plasma-facing (WP PFC) within the European programme complements laboratory experiments, i.e. in linear plasma devices, electron ion beam loading facilities, studies performed toroidally confined magnetic such as JET, ASDEX Upgrade, WEST etc. connection both groups done via...
The electron beam device JUDITH 1 was used to establish a testing procedure for the qualification of tungsten as plasma facing material. Absorbed power densities 0.19 and 0.38 GW m−2 an edge localized mode-like pulse duration ms were chosen. Furthermore, base temperatures room temperature, 400 °C 1000 allow investigating thermal shock performance in brittle, ductile high temperature regime. Finally, applying 100 pulses under all mentioned conditions helps qualifying general damage behaviour...
With the aim of a possible improvement material specification for tungsten, five different tungsten products by companies and production technologies (forging rolling) are subject to materials characterization program. Tungsten produced forging results in an uniaxial elongated grain shape while rolled have plate like which has influence on mechanical properties material. The were investigated with respect following parameters: hardness measurements, microstructural investigations, tensile...
The study summarizes the experimental results on fusion relevant pure heat load exposures of different tungsten products in electron beam devices JUDITH 1 and 2. Besides steady state loading, up to 106 transient ELM-like pulses were applied. A detailed postmortem analysis reveals a wide complex range thermally-induced surface modifications damages, such as roughening due plastic deformation, cracking, melting parts material surface. Different industrially available with varying thermal...
Combined thermal shock and steady-state heat loads (SSHLs) can have an impact on divertor materials are therefore important for lifetime estimations evaluations of operational thresholds components in future fusion devices such as ITER. This paper discusses the results tests performed electron beam facility JUDITH 2 (Forschungszentrum Jülich, Germany) actively cooled tungsten specimens, loaded with edge-localized mode-like shocks (pulse duration 0.48 ms, power densities 0.14–0.55 GW m−2,...
The influence of recrystallization on thermal shock resistance has been identified as an issue that may the long term performance ITER tungsten (W) divertor components. To investigate this a unique series experiments performed W monoblock mock-ups in three EU high heat flux facilities: GLADIS (neutral beam), JUDITH 2 (electron beam) and Magnum-PSI (plasma beam). simulate mitigated edge localised modes, fluxes between 0.11 0.6 GW m−2 were applied for Δt < 1 ms. Two different base...
In the full-tungsten divertor qualification program at ITER Organization, macro-cracks, so called self-castellation were found in a fraction of tungsten monoblocks during cyclic high heat flux loading 20MW/m2. The number with macro-cracks varied products used as armour material. order to understand correlation between macro-crack appearance and W properties, an activity characterize monoblock materials was launched IO. outcome highlighted that higher recrystallization resistance, lower...
Tungsten is an outstanding material and due to its properties like highest melting point tensile strength of all natural metals high thermal conductivity it a prime candidate for being used in very harsh environments challenging applications X-ray tubes or as plasma facing (PFM) fusion reactors. Unfortunately, brittle ductile transition temperature hardness represent great challenge classic manufacturing processes. Additive (AM) tungsten could overcome these limitations resulting design...
Wendelstein 7-X, the world's largest superconducting stellarator in Greifswald (Germany), started plasma experiments with a water-cooled plasma-facing wall 2022, allowing for long pulse operation. In parallel, project was launched 2021 to develop W based divertor, replacing current CFC demonstrate performance of reactor relevant facing materials low tritium retention. The consists two tasks: Based on experience from previous experimental campaigns and improved physics modelling, geometry...
Assessing the performance of ITER design for tungsten (W) divertor Plasma Facing Units (PFUs) in a tokamak environment is high priority issue to ensure efficient plasma operation. This paper reviews most recent results derived from experiments and post-mortem analysis ITER-grade PFUs exposed WEST associated modelling, with focus on understanding heat loading damage evolution. Several shaping options, sharp or chamfered leading edge (LE), unshaped shaped blocks toroidal bevel as foreseen...
The divertor is the key in-vessel plasma-facing component being in charge of power exhaust and removal impurity particles. In DEMO, targets must survive an environment high heat fluxes (~up to 20 MW m−2 during slow transients) neutron irradiation. One advanced concept for components monoblock configuration concerns insertion a compositionally graded layer between tungsten CuCrZr instead soft copper interlayer. As first step, thin (~25 μm) was developed. second thicker (~500 μm), which...
A micro-structuring of the tungsten plasma-facing surface can strongly reduce near thermal stresses induced by ELM heat fluxes. This approach has been confirmed numerical simulations with help ANSYS software. For experimental tests, two 10 × mm2 samples micro-structured were manufactured. These consisted 2000 and 5000 vertically packed fibres dimensions Ø240 µm 2.4 mm Ø150 mm, respectively. The 1.2 bottom parts are embedded in a copper matrix. top have gaps about so they not touching each...
Abstract Tungsten and tungsten-based alloys are the leading material choices for divertor plasma facing components (PFCs) in future fusion reactors. Recrystallization may occur when they undergo high heat loads, drastically modifying predesigned grain structures associated desired mechanical properties. However, influence of recrystallization on thermal fatigue behavior tungsten PFCs still remains unclear. In this study, ITER-grade was simultaneously exposed to a high-flux hydrogen (∼5 × 10...
The investigation of plasma facing materials (PFM) subjected to a large number (≥10,000) thermal shocks is interest determine long term morphological changes which might influence component lifetime in and performance fusion reactor. electron beam facility JUDITH 2 was used simulate these conditions experimentally. In this study eight different tungsten grades produced by powder injection molding (PIM) were investigated: Two pure grades, one with wt% Y2O3, three 1, 3 TiC, two 0.5 1 TaC....