J. Schilling
A5067355985- Magnetic confinement fusion research
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Parallel Computing and Optimization Techniques
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Astronomical Observations and Instrumentation
- Laser-induced spectroscopy and plasma
- Electrostatic Discharge in Electronics
- Electromagnetic Launch and Propulsion Technology
- Cloud Computing and Resource Management
- Advanced Data Storage Technologies
- Nuclear reactor physics and engineering
- Software Engineering Research
- Fluid Dynamics and Turbulent Flows
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
Max Planck Institute for Plasma Physics - Greifswald
2018-2024
Fusion Academy
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
Robert Koch Institute
2021
Kiel University
2017
Good Samaritan Hospital
2012
Micro Focus (United States)
1995
Abstract Research on magnetic confinement of high-temperature plasmas has the ultimate goal harnessing nuclear fusion for production electricity. Although tokamak 1 is leading toroidal magnetic-confinement concept, it not without shortcomings and community therefore also pursued alternative concepts such as stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) field geometry. The availability this additional dimension opens up an extensive configuration...
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...
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 transport of heavy impurities has been investigated at the Wendelstein 7-X stellarator during core electron root confinement (CERC) experiments. Iron atoms were injected via laser blow-off technique and analyzed by VUV x-ray spectrometers. amount iron does not change global plasma parameters but yields strong enough line radiation for detailed studies based on impurity code STRAHL. latter is supplied with neo-classical diffusion convection profiles from drift kinetic equation solver...
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 magnetic diagnostic system at the Wendelstein 7-X stellarator includes three diamagnetic loops to measure flux changes in plasma. Their signals are directly related plasma energy. design with respect materials, component cooling and data acquisition is built be fully steady-state capable within harsh environment of a fusion device. During first operational phase, two have been put into operation, each them close one up-down symmetric main planes column bean-shaped triangular-shaped...
Abstract Background: Advances in optics and instrumentation with the da Vinci S Surgical System have facilitated minimally invasive robotic cardiac procedures including mitral valve repair atrial myxoma excision. We report our retrospective data comparing robotically assisted excision standard median sternotomy Methods: Data were collected for resection performed between January 2000 December 2009. The resulting cohort included a total of 57 patients. These patients grouped into two...
We present a detailed overview and first results of the new laser blow-off system on stellarator Wendelstein 7-X. The allows impurity transport studies by repetitive controlled injection different tracer ions into plasma edge. A Nd:YAG is used to ablate thin metal film, coated glass plate, with repetition rate up 20 Hz. remote-controlled adjustable optical variation spot diameter enables positioning non-ablated areas target between pulses. During experiments, clear spectral lines from higher...
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.
Abstract Objective To characterize the clinical features of children and adolescents hospitalized with SARS-CoV-2 infections to explore predictors for disease severity. Design Nationwide prospective observational cohort study. Setting Data collected from 169 out 351 children’s hospitals in Germany between March 18, 2020 April 30, 2021 comparison Statutory Notification System. Participants 1,501 up 19 years age laboratory confirmed who were admitted subsequently reported COVID-19 registry...
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 The soft x-ray tomography diagnostic in the stellarator Wendelstein 7-X consists of twenty pinhole cameras, up–down symmetrically arranged a poloidal, triangular cross-section plasma vessel. emissivity is measured with 16 bit amplitude resolution at 2 MHz sampling rate along 360 lines-of-sight by silicon photodiode arrays. In recent operation campaign data acquisition (DAQ) has been working reliable for conducted pulse lengths <1 min, however DAQ system are ready foreseen 30 min...
Abstract The optimised superconducting stellarator W7-X generates its rotational transform by means of external coils, therefore no toroidal current is necessary for plasma confinement. Electron cyclotron drive experiments were conducted strikeline control and safe divertor operation. During periodic repetitive crashes the central electron temperature, similar to sawtooth in tokamaks, detected. Measurements from soft x-ray tomography emission show that are preceded weak oscillating...
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...
Abstract The energetic particle slowing down model in the BEAMS3D stellarator neutral beam code is compared to analytic models and experimental data from Wendelstein 7-X experiment (W7-X). Recently, first experiments were performed W7-X, providing validation of deposition codes (Lazerson S.A. et al 2020 Nucl. Fusion 60 076020). This work builds upon that work, follows gyro-center orbits neutral-beam-generated fast ions plasma boundary. Slowing times based on measurements diamagnetic energy...
This paper reports about a novel approach to the absolute intensity calibration of an electron cyclotron emission (ECE) spectroscopy system. Typically, ECE radiometer consists tens separated frequency channels corresponding different plasma locations. An overall diagnostic including near optics and transmission line is achieved with blackbody sources at LN2 temperature room via hot/cold mirror unit. As thermal source typically few thousand times lower than receiver noise temperature,...
Abstract Wendelstein 7-X (W7-X) (Greifswald, Germany) is an advanced stellarator, which uses the modular coil concept to realize a magnetic configuration optimized for fusion-relevant plasma properties. The magnet system of machine allows variation rotational transform (iota) at boundary. In latest W7-X operational phase dedicated scan has been performed varying between configurations with iota = 5/4 and 5/5 This paper presents overview experiments main results respect confinement stability....
First experimental observations in the Wendelstein 7-X stellarator indicate that impurity confinement can be explained by turbulent processes. In particular, plasma discharges with increased ion to electron temperature ratio are accompanied reduced density fluctuation amplitudes and anomalous diffusion, suggesting a lower transport. Employing gyro-kinetic numerical simulations, we argue plays key role for reducing gradient instability 7-X, leading an enhanced confinement.
In magnetic confinement fusion research, the achievement of high plasma pressure is key to reaching goal net energy production. The magnetohydrodynamic (MHD) model used self-consistently calculate effects induces on field confine plasma. Such MHD calculations serve as input for assessment a number important physics questions. VMEC code most widely evaluate 3D ideal-MHD equilibria, prominently present in stellarators. However, considering computational cost, it rarely large-scale or online...
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...
The magnetic diagnostic system at the optimized stellarator experiment Wendelstein 7-X (W7-X) includes a total number of 125 Mirnov coils, which are mounted inner plasma vessel wall. A wide range expected signal amplitudes, frequencies and mode numbers is covered to account for complex three-dimensional geometry W7-X. performed amplitude phase calibration individual coils including all relevant data acquisition components allows detailed spectral analysis. damped multiple classification...
Abstract Intrinsic, diffusion-driven toroidal (bootstrap) currents between −7 and 17 kA were measured in the optimised stellarator Wendelstein 7-X (W7-X) for several magnetic configurations at line-integrated plasma densities 2 × 10 19 1.6 20 m −2 heating powers 0.5 6 MW. The sign of bootstrap current changes with field reversal, its magnitude decreases mirror term rotational transform configuration as well density, increases power. Both absolute values dependencies agree neoclassical...
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...