J. Fellinger
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View article: On the limitations of CFD modelling of flow boiling at high flow velocities and high heat fluxes
On the limitations of CFD modelling of flow boiling at high flow velocities and high heat fluxes Open
The ability of computational fluid dynamics (CFD) models to predict flow boiling at high heat flux and high flow velocity conditions has been investigated. High heat fluxes of about 10 MW/m 2 and high flow velocities of about 10 m/s typica…
View article: On the limitations of CFD modelling of flow boiling at high flow velocities and high heat fluxes
On the limitations of CFD modelling of flow boiling at high flow velocities and high heat fluxes Open
International audience
View article: Overview of the first Wendelstein 7-X long pulse campaign with fully water-cooled plasma facing components
Overview of the first Wendelstein 7-X long pulse campaign with fully water-cooled plasma facing components Open
After a long device enhancement phase, scientific operation resumed in 2022. The main new device components are the water cooling of all plasma facing components and the new water-cooled high heat flux divertor units. Water cooling allowed…
View article: Multi-scale lumped modeling of micro-channels cooling structure for W7-X divertor unit target module
Multi-scale lumped modeling of micro-channels cooling structure for W7-X divertor unit target module Open
A novel concept for the cooling system of the W7-X divertor unit target module has been proposed, which involves tiles equipped with parallel arrays connected by hundreds of sub-millimeter rectangular micro-channels (MCs), obtained using A…
View article: Manufacturing, installation, commissioning and operation of endoscopes for monitoring water-cooled divertor in Wendelstein 7-X
Manufacturing, installation, commissioning and operation of endoscopes for monitoring water-cooled divertor in Wendelstein 7-X Open
The modular stellarator Wendelstein 7-X (W7-X) in Greifswald (Germany) started operation in 2015 with short pulse limiter plasmas and continued with pulsed divertor plasmas in 2017–2018. In 2022, operation phase (OP) 2.1 was run after inst…
View article: Pop-up Langmuir probe diagnostic in the water cooled divertor of Wendelstein 7-X
Pop-up Langmuir probe diagnostic in the water cooled divertor of Wendelstein 7-X Open
The design, development, and successful implementation of pop-up Langmuir probes installed in the water-cooled divertor of W7-X are described. The probes are controlled by drive coils (actuators) installed behind the divertor plates. These…
View article: Analysis of the neutral fluxes in the divertor region of Wendelstein 7-X under attached and detached conditions using EMC3-EIRENE
Analysis of the neutral fluxes in the divertor region of Wendelstein 7-X under attached and detached conditions using EMC3-EIRENE Open
This paper analyzes the neutral fluxes in the divertor region of the W7-X standard configuration for different input powers, both under attached and detached conditions. The performed analysis is conducted through EMC3-EIRENE simulations. …
View article: Analysis of the neutral fluxes in the divertor region of Wendelstein 7-X under attached and detached conditions using EMC3-EIRENE
Analysis of the neutral fluxes in the divertor region of Wendelstein 7-X under attached and detached conditions using EMC3-EIRENE Open
This paper analyzes the neutral fluxes in the divertor region of the W7-X standard configuration for different input powers, both under attached and detached conditions. The performed analysis is conducted through EMC3-EIRENE simulations. …
View article: Performance of tungsten plasma facing components in the stellarator experiment W7-X: Recent results from the first OP2 campaign
Performance of tungsten plasma facing components in the stellarator experiment W7-X: Recent results from the first OP2 campaign Open
The transition to reactor-relevant materials for the plasma facing components (PFCs) is an important and necessary step to provide a proof of principle that the stellarator concept can meet the requirements of a future fusion reactor by de…
View article: A multi-scale hybrid approach to the modelling and design of a novel micro-channel cooling structure for the W7X divertor
A multi-scale hybrid approach to the modelling and design of a novel micro-channel cooling structure for the W7X divertor Open
The second operating phase of the W7X stellarator, with an expanded set of plasma-facing components, includes the test of divertor tiles with a continuous heat load reaching 10 MW/m2. The divertor tiles are cooled by subcooled water. Here …
View article: Real-Time Detection of Overloads on the Plasma-Facing Components of Wendelstein 7-X
Real-Time Detection of Overloads on the Plasma-Facing Components of Wendelstein 7-X Open
Wendelstein 7-X (W7-X) is the leading experiment on the path of demonstrating that stellarators are a feasible concept for a future power plant. One of its major goals is to prove quasi-steady-state operation in a reactor-relevant paramete…
View article: Erosion of tungsten marker layers in W7-X
Erosion of tungsten marker layers in W7-X Open
In order to get first insight into net tungsten erosion in W7-X, tungsten (W) marker layers were exposed during the operational phase OP 1.2b at one position of the Test Divertor Unit (TDU), at 21 different positions of the inner heat shie…
View article: Understanding baffle overloads observed in high-mirror configuration on Wendelstein 7-X
Understanding baffle overloads observed in high-mirror configuration on Wendelstein 7-X Open
The operational regimes in the first divertor campaign of W7-X were limited by unexpectedly high heat loads on certain baffle tiles. In the high-mirror configuration, a permanent hotspot on the baffle plate was detected by the thermographi…
View article: Wall conditioning at the Wendelstein 7-X stellarator operating with a graphite divertor
Wall conditioning at the Wendelstein 7-X stellarator operating with a graphite divertor Open
Wall conditioning plays an important role in achieving record plasma performance on the superconducting stellarator Wendelstein 7-X (W7-X) by controlling plasma density and maintaining low levels of impurities. The development of the optim…
View article: Validating the ASCOT modelling of NBI fast ions in Wendelstein 7-X stellarator
Validating the ASCOT modelling of NBI fast ions in Wendelstein 7-X stellarator Open
The first fast ion experiments inWendelstein 7-X were performed in 2018. They are one of the first steps in demonstrating the optimised fast ion confinement of the stellarator. The fast ions were produced with a neutral beam injection (NBI…
View article: First divertor physics studies in Wendelstein 7-X
First divertor physics studies in Wendelstein 7-X Open
The Wendelstein 7-X (W7-X) optimized stellarator fusion experiment, which went into operation in 2015, has been operating since 2017 with an un-cooled modular graphite divertor. This allowed first divertor physics studies to be performed a…
View article: Nonlinear fatigue crack propagation in a baffle module of Wendelstein 7‐X under cyclic bending loads
Nonlinear fatigue crack propagation in a baffle module of Wendelstein 7‐X under cyclic bending loads Open
Simulation of the fatigue crack propagation in a Wendelstein 7‐X baffle module is performed in this study using both a finite element method‐based software and the UniGrow nonlinear model for small‐scale yielding (SSY) conditions. Some exp…
View article: Managing leading edges during assembly of the Wendelstein 7-X divertor
Managing leading edges during assembly of the Wendelstein 7-X divertor Open
Divertor target plates of magnetic confinement experiments are usually intersected by the magnetic field under a shallow angle. If steps are present in the target surface, the resulting leading edges will receive a strongly increased heat …
View article: Infrared imaging systems for wall protection in the W7-X stellarator (invited)
Infrared imaging systems for wall protection in the W7-X stellarator (invited) Open
Wendelstein 7-X aims at quasi-steady state operation with up to 10 MW of heating power for 30 min. Power exhaust will be handled predominantly via 10 actively water cooled CFC (carbon-fiber-reinforced carbon) based divertor units designed …
View article: A divertor scraper observation system for the Wendelstein 7-X stellarator
A divertor scraper observation system for the Wendelstein 7-X stellarator Open
Two graphite divertor elements called scrapers have been installed on the Wendelstein 7-X stellarator in the throat of the magnetic island divertor. To diagnose one, we have designed, built, calibrated, and installed a new infrared/visible…