A5028515508- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Laser Design and Applications
- Nuclear reactor physics and engineering
- GNSS positioning and interference
- Laser-induced spectroscopy and plasma
- Solid State Laser Technologies
- Laser-Matter Interactions and Applications
- Human-Automation Interaction and Safety
- Concrete and Cement Materials Research
- Solar and Space Plasma Dynamics
- Innovative concrete reinforcement materials
- Maritime Navigation and Safety
- Robot Manipulation and Learning
- Advanced Optical Sensing Technologies
- Advanced Frequency and Time Standards
- ECG Monitoring and Analysis
- Spacecraft and Cryogenic Technologies
- Hydraulic flow and structures
- Education, Psychology, and Social Research
Czech Academy of Sciences, Institute of Plasma Physics
2016-2025
Research Institute for Building Materials (Czechia)
2022
Charles University
2021
Czech Academy of Sciences
2012-2021
Czech Technical University in Prague
2005-2021
Culham Science Centre
2021
Brno University of Technology
2013
Austrian Institute of Technology
2009-2013
Abstract In 2021 JET exploited its unique capabilities to operate with T and D–T fuel an ITER-like Be/W wall (JET-ILW). This second major campaign (DTE2), after DTE1 in 1997, represented the culmination of a series enhancements—new fusion diagnostics, new injection capabilities, refurbishment plant, increased auxiliary heating, in-vessel calibration 14 MeV neutron yield monitors—as well as significant advances plasma theory modelling community. DTE2 was complemented by sequence isotope...
Abstract The quasi-continuous exhaust (QCE) regime is a that naturally type-I ELM-free. It combines the high density at plasma edge needed for power with normalised energy confinement typical H-mode operation. In QCE large-scale ELMs are avoided and high-frequent, low-amplitude filaments present leading to name-giving transport of particles energy.
This contribution reports first time was successfully achieved in JET metal wall. More so, it demonstrated recent deuterium-tritium...
This paper summarizes the status of COMPASS tokamak, its comprehensive diagnostic equipment and plasma scenarios as a baseline for future studies. The former COMPASS-D tokamak was in operation at UKAEA Culham, UK 1992–2002. Later, device transferred to Institute Plasma Physics Academy Sciences Czech Republic (IPP AS CR), where it installed during 2006–2011. Since 2012 has been full with Type-I Type-III ELMy H-modes base scenario. enables together ITER-like shape flexible NBI heating system...
COMPASS Upgrade is a new medium size, high magnetic field tokamak (R = 0.9 m, Bt 5 T, Ip 2 MA) currently under design in the Czech Republic. It will provide unique capabilities for addressing some of key challenges plasma exhaust physics, advanced confinement modes and configurations as well testing facing materials liquid metal divertor concepts. This paper contains an overview preliminary engineering main systems (vacuum vessel, central solenoid poloidal coils, toroidal support structure,...
Abstract The EUROfusion JET-ILW pedestal database is described, with emphasis on three main issues. First, the technical aspects are introduced, including a description of data selection, datasets, diagnostics used, experimental and theoretical methods implemented definitions. Second, structure stability described. In particular, work describes links between engineering parameters (power, gas divertor configuration) disagreement peeling-ballooning (PB) model ideal magnetohydrodynamics...
Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle role plasma fueling shape for onset small ELM regimes. On both devices, regimes with high confinement are achieved if only two conditions fulfilled at same time. Firstly, density separatrix must be large enough (), leading pressure profile flattening separatrix, which stabilizes type-I ELMs. Secondly, magnetic configuration close double null (DN), reduction shear in...
Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat particle loads on wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research ASDEX Upgrade (AUG), MAST TCV. This multi-machine approach within EU-MST, covering wide parameter range, instrumental progress in field, as ITER DEMO core/pedestal SOL parameters are not achievable simultaneously present day devices. A two prong adopted. On one...
Partial detachment is the desired regime for baseline burning plasma scenario in ITER and next-step devices, as it allows to dissipate majority of energy carried by charged particles through scrape-off-layer (SOL) thus avoids localised heat flux deposition divertor region.The COMPASS tokamak equipped with an open has a relatively short connection length, both factors being unfavourable access detachment.As such, only approach naturally detached operation at very high lineaveraged densities...
A new system of probes was recently installed in the divertor tokamak COMPASS order to investigate ELM energy density with high spatial and temporal resolution. The consists two arrays rooftop-shaped Langmuir (LPs) used measure floating potential or ion saturation current one array Ball-pen (BPPs) plasma a resolution ~3.5 mm. combination BPPs LPs yields electron temperature microsecond We report on design probe first results profile measurements ELMy H-mode L-mode. also present comparative...
The first-derivative probe technique was applied to derive data for plasma parameters from the IV Langmuir characteristics measured in boundary region COMPASS tokamak and TJ-II stellarator. It is shown that vicinity of last closed flux surface (LCFS) electron energy distribution function (EEDF) bi-Maxwellian with low-temperature fraction predominating over higher temperature one, whereas far scrape-off layer (SOL) EEDF Maxwellian. In stellarator during NBI heated confined close LCFS while...
The ball-pen probe (BPP) technique is used successfully to make profile measurements of the electron temperature on ASDEX Upgrade (Axially Symmetric Divertor Experiment), COMPASS (COMPact ASSembly), and ISTTOK (Instituto Superior Tecnico TOKamak) tokamak. provided by a combination BPP potential (ΦBPP) floating (Vfl) Langmuir (LP), which compared with Thomson scattering diagnostic COMPASS. Excellent agreement between two diagnostics obtained for circular diverted plasmas different heating...
Abstract The neutral ionisation model proposed by Groebner et al (2002 Phys. Plasmas 9 2134) to determine the plasma density profile in H-mode pedestal, is extended include charge exchange processes pedestal stimulated ideas of Mahdavi (2003 10 3984). then tested against JET data, both a ‘standalone’ version using experimental temperature profiles and also incorporating it Europed EPED. able predict over wide range conditions with good accuracy. It experimentally observed isotope effect on...
Abstract Microsecond probe measurements of the electron temperature during tokamak edge localised mode (ELM) instability show that peak values significantly exceed those obtained by conventional techniques. The temperatures measured at plasma facing component (divertor) are around 80% initial value (at pedestal). This challenges current understanding, where only several percent pedestal divertor. Our results imply a negligible energy transfer from electrons to ions ELM instability, and...
Abstract An analytical formula systematically predicts the observed frequency of pressure relaxation limit cycle oscillations in vicinity transition to high confinement four tokamaks (JET, ASDEX Upgrade, COMPASS, Globus-M). The experimental dataset spans widest available range frequencies, machine sizes and plasma ion species. size dependence is explained by connection length scale flows parallel magnetic field. model also explains up-down poloidal current asymmetry impact species mass charge.
The super-X divertor on MAST Upgrade will be diagnosed by a Thomson scattering diagnostic. A preliminary design of the collection optics and calculations diagnostic's performance are discussed in this paper. As part location size cell were optimized to minimize vignetting, especially region interest close strike point. process was complicated limited access available closed geometry. In study performance, radial resolution, projection laser image onto fiber bundle, impact depth field with...
This paper includes discussions of spatial resolution and accuracy the edge Thomson scattering system in ITER (ITER ETS). In present design, dominant factor for degradation relative to length is aberrations collection optics. A approximately 4 mm acceptable obtain a 5 mm. Statistical errors were evaluated according measurement accuracy. Since background light during plasma discharge much stronger than scattering, laser pulse duration one most crucial specifications accurate measurements. The...
The core Thomson scattering diagnostic (TS) on the COMPASS tokamak was put in operation and reported earlier. Implementation of edge TS, with spatial resolution along laser beam up to ∼1/100 minor radius, is presented now. procedure for calibration alignment both systems described. Several further upgrades TS system, like a triggering unit piezo motor driven vacuum window shutter, are introduced as well. together now routine provides electron temperature density profiles.
Abstract The reduction of the incident heat flux onto divertor will be a necessity for future thermonuclear reactors. Impurity seeding is recognized as an efficient way to achieve partial detachment regime, which allows dissipate large fraction power by radiation. This paper presents real-time feedback system (RTFS) based on impurity controlled combined ball-pen and Langmuir probe array in COMPASS tokamak. A number features have been studied, such type impurity, location, constants used...