A5014615184- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Ionosphere and magnetosphere dynamics
- Inorganic Chemistry and Materials
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Chemical Thermodynamics and Molecular Structure
- Hydrogen Storage and Materials
- Rare-earth and actinide compounds
- Nonlinear Dynamics and Pattern Formation
- Iron-based superconductors research
- Astronomical Observations and Instrumentation
- Nuclear Physics and Applications
- Theoretical and Computational Physics
- Physics of Superconductivity and Magnetism
- Thermal and Kinetic Analysis
- High-pressure geophysics and materials
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Inorganic Fluorides and Related Compounds
Forschungszentrum Jülich
1990-2018
Heinrich Heine University Düsseldorf
1998-2008
TU Bergakademie Freiberg
1967-2006
National University of Singapore
2006
Royal Military Academy
1993
Stadtwerke Jülich (Germany)
1988-1992
Max Planck Institute for Plasma Physics
1966-1991
National Institute for Fusion Science
1990
Princeton University
1990
Fusion Academy
1987-1990
The burn condition for D-T plasmas is derived in a form which accounts the stationary helium concentration determined by coupling of fusion power and production. ratio global alpha particle confinement time to energy τE taken as quantity characterizing prevailing exhaust regime. For an ignited burning plasma this needs remain sufficiently below 15 or 10 typical impurity concentrations. This poses lower limit on required efficiency indicates that operational regimes are needed where does not...
The Rayleigh-Taylor instability of a viscous liquid superimposed upon air can be dynamically stabilized by oscillating the perpendicularly to its horizontal equilibrium surface, thus maintaining position for an arbitrary time. viscosity was found have strong influence on stability short-wavelength modes. In parameter regime investigated effect compressibility gas negligible.
Stationary high energy confinement is observed on TEXTOR-94 for times limited only by the flux swing of transformer using strong edge radiation cooling. Necessary tools are feedback control radiated power and plasma content. At highest densities obtained (up to 1.2 Greenwald limit), exceeds edge-localized-mode-free H-mode scaling ITERH93-P more than 20%. β limits reached with fH89/qa≈0.6. No detrimental effect seeded impurity seen. These discharges meet many conditions necessary a fusion...
A total of 7.4 wt % hydrogen was released from the mixture magnesium amide and hydride at a molar ratio 1:2 by mechanical ball milling. Fourier Transform Infrared Spectroscopy (FTIR) X-ray Diffraction (XRD) characterizations along with amount different stages milling reveal that imide first formed in reaction. The then reacted continuously converted to nitride hydrogen. Thermodynamic calculation shows desorption is mild endothermic reaction standard enthalpy change about 3.5 kJ/mol H2.
Helium, as the ash of burning D-T plasma, is an unavoidable impurity component necessarily present already in near future tokamak experiments with significant alpha particle heating. Its efficient removal from zone a fusion reactor plays key role path towards achievement economic power production. A survey given issues related to this question. Since there yet no experimental experience thermonuclear plasmas significantly heated by products, review based on results simulation helium...
In a tokamak configuration, superposition of the magnetic field resonant helical windings which surround toroidal plasma current outside first wall destroys surfaces in boundary layer (ergodization). A transport model is analysed, where convective flow from to permits elevated particle densities and leads very high energy transport. The driven by pressure gradient along lines intersect at an oblique small angle . required thickness Δ around 1015 n−1·cm−2. As result, temperature there can be...
The first encouraging experiments demonstrating direct, explicit control of the ${\mathrm{He}}^{2+}$ density in a tokamak plasma have been performed TEXTOR with Advanced Limiter Test-II pump limiter. Helium is injected short gas puff from outside plasma, observed to reach core, and then readily removed plasma. An exhaust efficiency \ensuremath{\sim}8% obtained. Active charge-exchange spectroscopy used study transport within evolution modeled diffusive-convective code.
The radiative improved (RI) mode is a tokamak regime offering many attractive reactor features. In the article, RI of TEXTOR-94 shown to follow same scaling as linear ohmic confinement and thus identified one most fundamental operational regimes. current understanding derived from experiments modelling conditions necessary for sustaining reviewed, are mechanisms leading L-RI transition. article discusses compatibility high impurity seeding with low central power density burning reactor, well...
Improved confinement is achieved on TEXTOR under high power conditions (up to 4 MW of additional heating with NBI-co+ICRH, NBI-co+counter or NBI-co+counter+ICRH) edge radiative cooling employing silicon neon as the radiating impurities. It shown that in quasi-stationary up 85% input can be radiated. Such fractions offer possibility utilizing these techniques facilitate exhaust problem for a Tokamak reactor. Discharges exhibit enhanced properties at densities, e.g. central line averaged...
The Dynamic Ergodic Divertor (DED) is under construction as a novel tool for TEXTOR-94 to control transport at the plasma edge and possibly also rotation. DED has been laid out reference conditions rres(q = 3) βpol 1. operational space of analysed here. It shown that sufficient ergodization can be reached all relevant values (0 ⩽ 2). By shifting resonance layer close edge, degree substantially increased (by about factor 4). power supplies allow superposition base n 4 mode with 2 arbitrary...
An overview of the results obtained so far for radiative I-mode regime on upgraded Torus Experiment Technology Oriented Research (TEXTOR-94) [Proceedings 16th IEEE Symposium Fusion Engineering (Institute Electrical and Electronics Engineers, Piscataway, NJ, 1995), Vol. 1, p. 470] is given. This under quasistationary conditions with edge neon seeding in a pumped limiter tokamak circular cross section. It combines high confinement β (up to normalized beta, βn=2) low q values (down qa=2.8)...
Abstract The enthalpies of formation the nine cyclic ketones C n H 2n−2 O (n = 4–12) were determined by combustion calorimetry. heats vaporization measuring vapor pressure as a function temperature and fusion three compounds with 8, 9, 12 which are solids at room temperature, DSC.
Superimposed miscible liquids, the heavier one on top, when subjected to vibrations vertical their interface (dynamic stabilization), can only be maintained for a certain period. A mechanism is presented explaining resulting process of degradation and “anomalous diffusion” through that interface. lighter exposed horizontal vibrations, develop saw-tooth-like pattern called “frozen waves.” These are subject conditions similar those dynamic stabilization and, if miscible, thus also further...
An overview is presented of recent experiments with radiating mantles on limiter and divertor machines, realizing simultaneously high confinement density at high-radiation levels. A variety operational regimes has been observed the characteristics each are documented. High-performance plasmas (i.e. edge localized mode (ELM)-free H-mode quality normalized beta values simultaneously) have demonstrated under quasistationary conditions during maximum flattop time machine (equal to tens times)...
The paper summarizes the main results obtained during first six months of experimental work on TEXTOR with ohmically heated plasmas. machine(R = 175 cm; a 45-50 cm) was operated at wall temperatures up to 303 oC hydrogen gas, toroidal field 2 T and maximum plasma current 500 kA, yielding central electron 1.2 keV, line-averaged densities 4 x 1013 cm-3 discharge durations 2.7 sec (for Ip⩽340 kA). Besides providing long-lasting reproducible plasmas for forthcoming interaction research,...
Four new low field side antennae grouped in pairs have been installed on TEXTOR. It is found that the interaction with wall (density rise, impurity generation) significantly reduced when operating each pair out of phase ( pi ) as opposed to (0). The beneficial effect configuration obtained without drop plasma loading. This experimental property shown, from theory, be explained by judicious choice geometrical configuration. A further improvement made possible an appropriate conditioning (wall...
Ion cyclotron heating on TEXTOR has now reached the Megajoule level. The scenario is normally mode conversion but occasionally minority in a D-(H) plasma. With appropriate wall conditioning by carbonization more than 1 MW of RF power been injected for long pulse durations ( approximately s). ICRF heated plasma characterized quasi-stationarity all parameters, little if no impurity increase and loop voltage reduction resulting total coupled to reaching six times remaining ohmic input. Evidence...