A5044595265- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Nuclear Materials and Properties
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Vacuum and Plasma Arcs
- Nuclear Physics and Applications
- Metallurgical Processes and Thermodynamics
- Spacecraft and Cryogenic Technologies
- Flexible and Reconfigurable Manufacturing Systems
- Prostate Cancer Diagnosis and Treatment
- Prostate Cancer Treatment and Research
- Corporate Governance and Management
- Atomic and Molecular Physics
- Telomeres, Telomerase, and Senescence
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Genetic factors in colorectal cancer
- Ion-surface interactions and analysis
Max Planck Institute for Plasma Physics
2016-2025
Helios Kliniken
2022
Max Planck Society
2012-2021
Royal Military Academy
2020
Max Planck Institute of Quantum Optics
2019
National Agency for New Technologies, Energy and Sustainable Economic Development
2019
University of Padua
2019
Max Planck Innovation
2002-2017
Institute for Particle and Nuclear Physics
2016
HUN-REN Wigner Research Centre for Physics
2016
Large-conductance calcium- and voltage-activated potassium channels (BK Ca ) are dually activated by membrane depolarization elevation of cytosolic calcium ions (Ca 2+ ). Under normal cellular conditions, BK channel activation requires concentrations that typically occur in close proximity to sources. We show affinity-purified from rat brain assembled into macromolecular complexes with the voltage-gated Cav1.2 (L-type), Cav2.1 (P/Q-type), Cav2.2 (N-type). Heterologously expressed -Cav...
Detachment of high power discharges is obtained in ASDEX Upgrade by simultaneous feedback control core radiation and divertor or thermoelectric currents the injection radiating impurities. So far 2/3 ITER normalized heat flux Psep/R = 15 MW m−1 has been under partially detached conditions with a peak target well below 10 m−2. When detachment further pronounced towards lower at target, substantial changes edge localized mode (ELM) behaviour, density distribution occur. The time-averaged both...
The tungsten programme in ASDEX Upgrade is pursued towards a full high-Z device. spectroscopic diagnostic of W has been extended and refined the cooling factor re-evaluated. coated surfaces now represent fraction 65% all plasma facing components (24.8 m2). only two major that are not yet strikepoint region lower divertor as well limiters at low field side. While extending surfaces, concentration discharge behaviour have changed gradually pointing to critical issues when operating with wall:...
Feedback control of the divertor power load by means nitrogen seeding has been developed into a routine operational tool in all-tungsten clad ASDEX Upgrade tokamak. For heating powers above about 12 MW, its use become inevitable to protect tungsten coating under boronized conditions. The is accompanied improved energy confinement due higher core plasma temperatures, which more than compensates negative effect dilution on neutron rate. This paper describes technical details feedback...
Recent research in scrape-off layer (SOL) and divertor physics is reviewed; new existing data from a variety of experiments have been used to make cross-experiment comparisons with implications for further ITER. Studies the region near separatrix addressed relationship profiles turbulence as well scaling parallel power flow. Enhanced low-field side radial transport implicated driving flows inboard side. The medium-n nature edge localized modes (ELMs) has elucidated measurements determined...
Abstract A mild and robust heterogeneous palladium‐catalyzed CO bond cleavage of 2‐aryloxy‐1‐arylethanols using formic acid as reducing agent in air was developed. The cleaved products were isolated 92–98 % yield; by slightly varying the reaction conditions, a ketone, an alcohol, or alkane can be generated near‐quantitative yield. This is applicable to cleaving β‐ O ‐4′‐ether found lignin polymers different origin. performed on polymer model generate either monomeric aryl ketone...
The plasma diagnostic and control (D&C) system for a future tokamak demonstration fusion reactor (DEMO) will have to provide reliable operation near technical physics limits, while its front-end components be subject strong adverse effects within the nuclear high temperature environment. ongoing developments ITER D&C represent an important starting point progressing towards DEMO. Requirements detailed exploration of are however pushing design using sophisticated methods aiming large spatial...
A new shattered pellet injection system was designed and built to perform disruption mitigation experiments on ASDEX Upgrade. The can inject pellets with diameters of 1, 2, 4, or 8 mm variable lengths over a range L/D ratios ∼0.5-1.5. By using helium deuterium as propellant gas, the be accelerated speeds between 60 750 m/s. velocity slightly depends mass. is capable preparing three in separate barrels at same time. Once by gas pulse, travel through one parallel flight tubes. Each tube...
Abstract In future fusion reactors, extended melt pools in combination with strong plasma-induced accelerations, suggest that the metallic could reach gaps between castellated plasma-facing components, potentially accompanied by profound changes their mechanical response. The first results of a combined experimental and modelling effort to elucidate physics transport across are presented. Transient melting specially designed tungsten samples featuring toroidal has been achieved ASDEX Upgrade...
In the ASDEX Upgrade tokamak, power deposition structures on divertor target plates during type-I edge localized modes (ELMs) have been investigated by infrared thermography. addition to axisymmetric strike line, several poloidally displaced stripes are resolved, identifying an ELM as a composite of subevents. This pattern is interpreted being signature helical perturbations in low field side non-linear evolution. Based this observation, related magnetic perturbation midplane can be derived...
ASDEX Upgrade has recently finished its transition towards an all-W divertor tokamak, by the exchange of last remaining graphite tiles to W-coated ones. The plasma start-up was performed without prior boronization. It found that large He content in plasma, resulting from DC glow discharges for conditioning, leads a confinement reduction. After change D inter-shot quickly dropped and, parallel, usual H-Mode with H factors close one achieved. initial conditioning phase, oxygen concentrations...
After completion of the tungsten coating all plasma facing components, ASDEX Upgrade has been operated without boronization for 1 1/2 experimental campaigns. This allowed study fuel retention under conditions relatively low D co-deposition with low- Z impurities as well operational space a full-tungsten device unfavourable condition high intrinsic impurity level. Restrictions in operation were caused by central accumulation combination density peaking, resulting H–L backtransitions induced...
In 2008, experiments have been carried out in ASDEX Upgrade to compare Hmode power threshold and confinement time helium deuterium.A scan magnetic field a wide density variation indicate that the two gases is very similar.The dependence of exhibits clear minimum.Confinement about 30% lower than deuterium, mainly due reduction ion caused by Z=2 helium.
The dust collection and analysis strategy in ASDEX Upgrade (AUG) is described. During five consecutive operation campaigns (2007–2011), Si collectors were installed, which supported by filtered vacuum sampling with adhesive tapes 2009. outer inner morphology (e.g. shape) elemental composition of the collected particles analysed scanning electron microscopy. majority ∼50 000 on campaign 2009 contain tungsten—the plasma-facing material AUG—and show basically two different types appearance:...
In ASDEX Upgrade with full-tungsten wall, boronization is an important tool to control tungsten sources and allow reliable operation at low collisionality. The duration of the beneficial effects limited by erosion boron layer, in particular on ion-cyclotron antenna limiters. We report results from experiments exploring injection boron-rich powders tokamak plasmas as a way replenish coating extend lifetime effects. Pure nitride were introduced gravitationally plasma discharges rates up 60...
Abstract Particle balance calculations are done for the seeding species N 2 , Ne, Ar, Kr as well He with aim of obtaining a realistic description divertor and core plasma impurity content. Experimental time traces main densities fitted by single, time-independent parameter v <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi/> <mml:mi>z</mml:mi> <mml:mo>,</mml:mo> <mml:mtext>in</mml:mtext> </mml:mrow> <mml:mtext>eff</mml:mtext>...
At the central column of ASDEX Upgrade, an area 5.5 m2 graphite tiles was replaced by tungsten-coated representing about two-thirds total column. No negative influence on plasma performance found, except for internal transport barrier limiter discharges. The tungsten influx ΓW stayed below detection limit only during direct wall contact or reduced clearance in divertor discharges spectroscopic evidence could be found. From these observations a penetration factor order 1% and effective...
Plasma operation with high-Z plasma facing components is investigated regard to sputtering, core impurity contamination and scenario restrictions. A simple model based on dimensionless quantities for fuel ion sources transport describe the concentration in introduced. The release further factorized into sputtering yield, relative pedestal penetration probability a confinement enhancement factor. Since there are quite large uncertainties, particular, source edge of impurities, very different...
The elements of transport into and across the scrape-off layer in poloidal divertor tokamak ASDEX Upgrade are analysed for different operational regimes with emphasis on enhanced confinement an edge barrier. Utilizing existing set diagnostics, especially high-resolution multi-pulse Thomson scattering system, combination long discharge plateaus, radial sweeps advanced averaging techniques, detailed mid-plane profiles diverted plasmas obtained. Profiles smooth separatrix, indicating strong...
The evaluation of hydrogenic retention in present tokamaks is crucial importance to estimate the expected tritium (T) vessel inventory ITER, limited from safety considerations 350 g. In framework European Task Force on Plasma Wall Interaction (EU TF PWI) efforts are underway investigate gas balance and fuel during discharges, compare data obtained with those post-mortem analysis in-vessel components exposed over whole experimental campaigns. This paper summarizes principal findings...