A5017257855- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Nuclear Materials and Properties
- Metal and Thin Film Mechanics
- Laser-induced spectroscopy and plasma
- Antenna Design and Optimization
- High-pressure geophysics and materials
- Antenna Design and Analysis
- Dust and Plasma Wave Phenomena
- Magnetic Field Sensors Techniques
- GNSS positioning and interference
- Electromagnetic Simulation and Numerical Methods
- Engineering Applied Research
- Atomic and Subatomic Physics Research
- Electromagnetic Launch and Propulsion Technology
- Gyrotron and Vacuum Electronics Research
- Ion-surface interactions and analysis
Max Planck Institute for Plasma Physics
2015-2025
Institut de Recherche sur la Fusion par Confinement Magnétique
2024
CEA Cadarache
2024
National Agency for New Technologies, Energy and Sustainable Economic Development
2022
University of Padua
2022
Max Planck Society
2014-2021
Technical University of Munich
2018
Institut Jean Lamour
2015
Ghent University
2015
Université de Lorraine
2015
The object of this review is to summarize the achievements research on Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] place that in context quest for practical fusion energy. a compact, high-field tokamak, whose unique design operating parameters have produced wealth new important results since it began operation 1993, contributing data extends tests critical physical models into parameter ranges regimes. Using only...
The European DEMO is a pulsed device with pulse length of 2 hours. functions devoted to the heating and current drive system are: plasma breakdown, ramp-up flat-top where fusion reactions occur, control during phase, finally ramp-down. EU-DEMO project was in Pre-Concept Design Phase 2014-2020, meaning that some cases, design values precise requirements from physics point view were not yet frozen. A total 130 MW considered for all phases plasma: flat top, 30 required neoclassical tearing...
A comparison of the ASDEX Upgrade 3-strap ICRF antenna data with linear electromagnetic TOPICA calculations is presented.The substantiates a reduction local electric field at radially protruding plasma-facing elements as relevant approach for minimizing tungsten (W) sputtering in conditions when slow wave strongly evanescent.The measured reaction time-averaged RF current limiters to feeding variations less sensitive than predicted by calculations.This likely have been caused temporal and...
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
A novel type of transport barrier for reducing turbulent in the core a high temperature magnetically confined fusion plasma has been observed during experiments performed on ASDEX Upgrade tokamak.
Ion cyclotron range of frequency (ICRF) heating is expected to provide auxiliary for ITER and future fusion reactors where high Z metallic plasma facing components (PFCs) are being considered. Impurity contamination linked ICRF antenna operation remains a major challenge particularly devices with PFCs. Here, we report on an experimental investigation test whether field aligned (FA) can reduce impurity sources. We compare the modification scrape layer (SOL) potential FA conventional,...
Abstract The 3-strap antennas in ASDEX Upgrade allow ICRF operation with low tungsten (W) content the confined plasma W-coated antenna limiters. With configuration, local W impurity source at is drastically reduced and core concentration similar to that of boron coated 2-strap a given power. Operation power ratio between central outer straps <?CDATA $1.5:1$ ?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mstyle displaystyle="false"> <mml:mn>1.5</mml:mn>...
Abstract A set of dedicated H-mode discharges with constant heating power combining Neutral Beam Injection and Electron Cyclotron Resonance Heating have been executed at the ASDEX Upgrade tokamak using a high triangularity magnetic geometry in order to investigate impact filamentary transport divertor non-divertor components. The evolution upstream scrape-off layer (SOL) profiles correlated separatrix quantities, mostly turbulence control parameter <mml:math...
This paper briefly describes intrinsic and collaborative scientific activities of the Stellarator Department (Institute Plasma Physics National Science Center “Kharkiv Institute Technology”) within last two years. These include experiments numerical modeling for JET, Asdex-U TCV European tokamaks, stellarators Wendelstein 7-X, TJ-II, LHD, Heliotron-J Uragan-2M, TOMAS toroidal device theoretical studies related to conceptual development stellarator-mirror fission-fusion hybrid.
Abstract For successfully heating plasma with waves in the Ion Cyclotron Range of Frequencies (ICRF), mitigating impurity production is just as crucial maximizing power coupling, especially high-Z environments [Urbanczyk 2021]. Only when coupled limited influence on production, can ICRF truly become a powerful tool to directly deposit energy ions, modify turbulence-driven transport and enhance efficiency fusion reactions. &#xD;To do so, one must rely toroidal array at least three active...
A comparison of the impact additional central electron cyclotron resonance heating (ECRH) and ion (ICRH) on behaviour tungsten (W) density in core H-mode plasmas heated with neutral beam injection (NBI) is performed ASDEX Upgrade.Both localized broad profiles power ECRH have been obtained, where reproduce profile shape ICRH density, which applied a hydrogen minority scheme.In contrast to ECRH, produces direct only, eventually heats both electrons ions almost equal fractions.It found that RF...
Recent achievements in studies of the effects ICRF (Ion Cyclotron Range Frequencies) power on SOL (Scrape-Off Layer) and PWI (Plasma Wall Interactions) ASDEX Upgrade (AUG), Alcator C-Mod, JET-ILW are reviewed. Capabilities to diagnose model effect DC biasing associated impurity production at active antennas magnetic field connections described. The experiments show that near-fields can lead not only E × B convection, but also modifications density, which for C-Mod limited a narrow region...
The B-dot probe diagnostic suite on the ASDEX Upgrade tokamak has recently been upgraded with a new 125 MHz, 14 bit resolution digitizer to study ion cyclotron emission (ICE). While classic edge from low field side plasma is often observed, we also measure waves originating core fast fusion protons or beam injected deuterons being possible driver. Comparing measured frequency values harmonics present in places origin of this magnetic axis, fundamental hydrogen/second deuterium harmonic...
Abstract As part of ITPA-Integrated Operational Scenario activities, this contribution reviews recent experimental characterizations radio-frequency (RF)-induced scrape-off layer (SOL) modifications various tokamaks worldwide and the LArge Plasma Device at UCLA. The phenomenology, as observed using a large variety measurement techniques, is consistent with expectations from RF sheath rectification. Emphasis then put on complex three-dimensional (3D) spatial patterns RF–SOL interaction, in...
An extensive experimental survey of plasma potentials induced by ion cyclotron range-of frequency (ICRF) heating was carried out in the scrape-off layer (SOL) plasmas on Alcator C-Mod tokamak. Enhanced >100 V are observed at locations where local magnetic fields map to active ICRF antennas. In these cases, enhanced potential appears only when a density threshold is surpassed—a that quantitatively consistent with slow wave (SW) RF rectification theory. However, many cases large enhancements...
This paper introduces a new model to find the velocity-space location of energetic ions generating ion cyclotron emission (ICE) in plasmas. ICE is thought be generated due inverted gradients v⊥ direction velocity distribution function or anisotropies, i.e., strong pitch direction. Here, we invert synthetic spectra from first principles PIC-hybrid computations locations these ICE-generating space terms probability function. To this end, compute 2D weight functions based on magnetoacoustic...
The ion temperature is not frequently measured in the boundary of magnetic fusion devices. Comparisons among different techniques and simulations are even rarer. Here we present a comparison measurements Alcator C-Mod tokamak from three diagnostics: charge exchange recombination spectroscopy (CXRS), an sensitive probe (ISP), retarding field analyzer (RFA). Comparison between CXRS ISP along with close examination reveals that space limited. It thus unable to measure high density (>1019 m−3)...
Langmuir probe diagnostic on magnetic plasma devices often encounters more challenges in data processing than non-magnetized plasmas, the latest itself being far from simple. In this paper, a theory of particle collection by at potential collisionless weakly ionized plasmas is constructed, accounting for velocities distributed according to Maxwell equation and different mechanisms depending their speed. Experimental validation presented has been done with 2 cylindrical probes (rpr = 75 μm...
Core ion cyclotron emission (ICE) signals have recently been observed in beam-heated plasmas on several tokamaks. In this manuscript we present experimental evidence support of core ICE being generated by the magnetoacoustic instability (MCI), itself driven velocity-space inversion sub-Alfvénic beam-injected ions. The amplitude evolution is consistent with MCI and a result competition between beam fraction build-up (which increases growth rate) slowing down dominant velocity component...
Abstract Sawtooth oscillations in tokamaks frequently lead to the redistribution of energetic ions, mainly on passing orbits, causing their expulsion from core. This paper discusses first measurements interaction fast ions and sawteeth Large Helical Device. The crashes were caused by plasma current induced Electron Cyclotron Current Drive Neutral Beam Drive. Despite these crashes, there was no detectable effect either core or at edge plasma.
This paper summarizes highlights of research results from the Alcator C-Mod tokamak covering period 2006–2008. Active flow drive, using mode converted ion cyclotron waves, has been observed for first time in a plasma, mix D and 3 He species; toroidal poloidal flows are driven near location conversion layer. ICRF induced edge sheaths implicated both erosion thin boron coatings generation metallic impurities. Lower hybrid range frequencies (LHRF) microwaves have used efficient current profile...
A new Retarding Field Analyzer (RFA) head has been created for the outer-midplane scanning probe system on Alcator C-Mod tokamak. The contains back-to-back retarding field analyzers aligned with local magnetic field. One faces “upstream” into field-aligned plasma flow and other “downstream” away from flow. RFA was primarily to benchmark ion temperature measurements of an sensitive probe; it may also be used interrogate electrons. However, its construction is robust enough measure electron...
A new B-dot probe-based diagnostic has been installed on an ASDEX Upgrade tokamak to characterize ion cyclotron range-of frequency (ICRF) wave generation and interaction with magnetized plasma. The consists of a field-aligned array probes, oriented measure fast slow ICRF fields their wavenumber (k(//)) spectrum the low field side Upgrade. thorough description supporting electronics is provided. In order compare measured dominant local expected launched waves, in-air near-field measurements...
Abstract Ion cyclotron range of frequencies (ICRF) wave propagation is calculated theoretically for tokamak conditions and linear magnetized plasma device IShTAR which dedicated to the RF sheath studies. Only slow (SW) mode ICRF waves can propagate be studied in IShTAR. Therefore it possible decouple role different modes effects. Numerical simulations SW are done COMSOL framework existing cold modelling package RAPLICASOL first time modelled 3D. To date, existed as a 3D coupling approach...
Abstract Bursts of ion cyclotron emission (ICE), with spectral peaks corresponding to the hydrogen harmonic frequencies in plasma core are detected from helium plasmas heated by sub-Alfvénic beam-injected ions ASDEX Upgrade tokamak. Based on fast distribution function obtained TRANSP/NUBEAM code, together a linear analytical theory magnetoacoustic instability (MCI), growth rates MCI could be calculated. In our theoretical and experimental studies, we found that excitation mechanism ICE...