A. Puig Sitjes
A5072372522- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Electromagnetic Launch and Propulsion Technology
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Laser-induced spectroscopy and plasma
- Gas Dynamics and Kinetic Theory
- X-ray Spectroscopy and Fluorescence Analysis
- Astronomical Observations and Instrumentation
- Infrared Target Detection Methodologies
- Anomaly Detection Techniques and Applications
- Fluid Dynamics and Turbulent Flows
- Engineering Applied Research
- Optical Systems and Laser Technology
- Geophysics and Gravity Measurements
- Advanced Image Processing Techniques
- Geomagnetism and Paleomagnetism Studies
- Advanced Neural Network Applications
Max Planck Institute for Plasma Physics - Greifswald
2016-2024
Max Planck Institute for Plasma Physics
2017-2021
Max Planck Society
2017-2021
Princeton Plasma Physics Laboratory
2021
HUN-REN Centre for Energy Research
2021
Universitat Politècnica de Catalunya
2005
Wendelstein 7-X is the first comprehensively optimized stellarator aiming at good confinement with plasma parameters relevant to a future power plant. Plasma operation started in 2015 using limiter configuration. After installing an uncooled magnetic island divertor, extending energy limit from 4 80 MJ, continued 2017. For this phase, electron cyclotron resonance heating (ECRH) capability was extended 7 MW, and hydrogen pellet injection implemented. The enhancements resulted highest triple...
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 actively water cooled CFC (carbon-fiber-reinforced carbon) based divertor units designed withstand loads MW/m2 locally in steady state. If local exceed this value, a risk delamination the and failure entire modules arises. Infrared endoscopes monitor all main plasma facing components are being prepared, near real time software tools under...
Abstract Wendelstein 7-X (W7-X), the largest advanced stellarator, is built to demonstrate high power, performance quasi-continuous operation. Therefore, in recent campaign, experiments were performed prepare for long pulse operation, addressing three critical issues: development of stable detachment, control heat and particle exhaust, impact leading edges on plasma performance. The exhaust W7-X realized with help an island divertor, which utilizes large magnetic islands at boundary. This...
For stellarators, which need no or only small amounts of current drive, electron-cyclotron-resonance heating (ECRH) is a promising method even for the envisaged application in fusion power plant. Wendelstein 7-X (W7-X) equipped with steady-state capable ECRH system, operating at 140 GHz, corresponds to 2nd cyclotron harmonic electrons magnetic field 2.5 T. Ten gyrotrons are operational and already delivered 7 MW W7-X plasmas. Combined pellet injection, highest triple product (0.68 × 1020 keV...
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 at pulse energies up 80 MJ, as opposed 4 MJ the phase, where five inboard limiters were installed instead of a This, and number other upgrades device capabilities, extension regimes higher plasma density, heating power, performance overall, e.g. setting new...
Abstract Classical particle drifts are known to have substantial impacts on fluxes of particles and heat through the edge plasmas in both tokamaks stellarators. Here we present results from first dedicated investigation drift effects W7-X stellarator. By comparing similar plasma discharges conducted with a forward- reverse-directed magnetic field, could be isolated observation up-down asymmetries flux profiles divertor targets. In low-density plasmas, radial locations strike lines (i.e....
Pulsed injections of boron carbide granules into Wendelstein 7-X stellarator (W7-X) plasmas transiently increase the plasma stored energy and core ion temperatures above reference W7-X experimental programs by up to 30%. In a series 4 MW electron cyclotron resonance heating experiments, PPPL Probe Mounted Powder Injector provided 50 ms bursts 100 μm every 350 at estimated quantities ranging from approximately 1 mg/pulse over 30 mg/pulse. For each injection, was observed initially drop...
The role of error fields in stellarators is explored this work through simulations of, and experiments performed on, the Wendelstein 7-X (W7-X) stellarator. Previous experimental results, based on limiter plasmas W7-X, suggest that are small experiment plasmas. In work, we document results from first divertor campaign W7-X with a focus resonant edge island structure. Measurements obtained using thermocouples corroborate earlier correctable, requiring only 5% total rated current trim coil...
The W7-X Scrape-Off Layer (SOL) with its characteristic magnetic island chain has been investigated using electric probes mounted on a reciprocating manipulator close to the outboard mid-plane.A survey of configuration space shows that presence and particular topology islands significantly affects SOL profiles electron temperature, density, field plasma flows.Particularly relevant for divertor operation, very wide heat flux have observed in some configurations, which we link islands.In these...
The paper presents procedures which have been developed for a quantitative analysis of the divertor power deposition at Wendelstein 7-X. development these tools is motivated by need to compare and verify scientific engineering predictions with experimental measurements. measurements performed means thermographic diagnostic system, capable exploring heat loads, aim study load symmetry, footprint patterns theoretical expectations, but also investigate leading edges misalignment. In order...
The paper presents experimental observations and simulations for the effects of toroidal plasma current on divertor power depositions W7-X.With increasing accompanying changes in island geometry result a sweep strike line redistribution heat flux footprints.Good agreement between experiments, which partly used electron cyclotron drive to generate an additional contribution, modelling using field tracing vacuum magnetic fields including ad-hoc axis is found both standard low-iota configurations.
The 3D effects on divertor heat loads have been investigated for performance-optimized island configurations at Wendelstein 7-X with modeling and IR camera measurements. A new high mirror configuration optimized more stable operation due to reduced bootstrap currents a even load distribution between the main targets has first time numerically experimentally. Transport calculations EMC3-EIRENE show strong dependence of flux distributions details geometry. measurements confirm predictions...
The neutral beam deposition model in the BEAMS3D code is validated against attenuation data from Wendelstein 7-X (W7-X). A set of experimental discharges where injection system W7-X was utilized were reconstructed. These scanned magnetic configurations and plasma densities W7-X. equilibrium reconstructions performed using STELLOPT which calculates three-dimensional self-consistent ideal magnetohydrodynamic equilibria kinetic profiles. leveraged new capabilities to incorporate electron...
Abstract In the previous divertor campaign, Wendelstein 7-X (W7-X) device injected 3.6 MW of neutral beam heating power allowing for achievement densities approaching 2 × 10 20 m −3 , and providing first initial assessment fast ion confinement in a drift optimized stellarator. The injection (NBI) system on W7-X is comprised two boxes with space four radio frequency sources each. reported this work was achieved NI21 box. effect combined electron-cyclotron resonance (ECRH) NBI explored through...
The Wendelstein 7-X (W7-X) fusion experiment is aimed at proving that the stellarator concept suitable for a future reactor. Therefore, it designed steady-state plasmas of up to 30 min, which means thermal control plasma-facing components (PFCs) vital importance prevent damage device.In this paper an overview design Near Real-Time Image Diagnostic System (hereinafter called "the System") PFCs protection in W7-X presented. goal monitor with high risk permanent due local overheating during...
Machine protection is a core task of real-time image diagnostics aiming for steady-state operation in nuclear fusion devices. The paper evaluates the applicability newest low-power NVIDIA Jetson Xavier NX platform plasma diagnostics. This embedded Tegra System-on-a-Chip (SoC) integrates Graphics Processing Unit (GPU) and Central (CPU) on single chip. hardware differences features compared to previous TX2 are signified. Implemented algorithms detect thermal events real-time, utilising high...
The first fast ion experiments in Wendelstein 7-X were performed 2018. They are one of the steps demonstrating optimised confinement stellarator. ions produced with a neutral beam injection (NBI) system and detected infrared cameras (IR), loss detector (FILD), charge exchange spectroscopy (FIDA), post-mortem analysis plasma facing components. distribution function at wall is being modelled ASCOT suite codes. calculate ionisation injected neutrals consecutive slowing down process ions....
The control of rotational transform in Wendelstein 7-X (W7-X) is key to both the island divertor operation and safety plasma facing components. concept W7-X relies on an edge flux surface with resonating intrinsic n/m = 5/5 resonance form a five lobed chain. This chain intersects plates give rise divertor. Changes relative position rational can result changes performance, thus essential device. During first campaign electromagnetic loads resulted elastic deformations shaped modular...
Wendelstein 7-X (W7-X) is the most advanced fusion experiment in stellarator line and aimed at proving that concept suitable for a reactor. One of important issues reactors monitoring plasma facing components when exposed to very high heat loads, through use visible infrared (IR) cameras. In this paper, new image processing system analysis strike lines on inboard limiters from first W7-X experimental campaign presented. This builds model IR cameras spatial calibration techniques, helping...
Abstract The role of toroidal plasma currents for the island divertor scrape-off layer in stellarator Wendelstein 7-X is investigated using reciprocating electric probes. Experiments show that small amounts (of a few kA) current are sufficient to significantly affect conditions, whereas higher above 10kA result more drastic changes. This behavior linked effect on rotational transform profile, which can significant shifts edge magnetic islands. These interaction islands with and eventually...
Wendelstein 7-X(W7-X), an optimized stellarator, conducted its first divertor operation. It uses island concept for the heat and particle exhaust. Large wetted areas of up to 1.5 m2 have been reached, showing benefits very efficient flux spreading. Moreover, a positive scaling area with increasing SOL power is observed, which important operations at high input power. A definition made based on thermographic camera observations 3D structure W7-X comparability definitions other machines (e.g....
Abstract Investigations of particle parallel flow velocities have been carried out for the scrape-off layer (SOL) Wendelstein 7-X (W7-X) stellarator, in order to gain insights on SOL transport properties during attached and detached plasma scenarios. The experimental evidence is based coherence imaging spectroscopy (CIS) diagnostic, able measure 2D impurity emission intensity velocity. monitored by CIS C 2+ , characterized a line-emission observed be linearly proportional total radiated...
The operational regimes in the first divertor campaign of W7-X were limited by unexpectedly high heat loads on certain baffle tiles. In high-mirror configuration, a permanent hotspot plate was detected thermographic system, which further confirmed during post-campaign inspections plasma-facing components. maximum load three tiles reached about 4.5 MW m−2, almost an order magnitude above its designed value 0.5 m−2. paper presents detailed analysis to understand how plate, is originally screen...