A5039587947- Magnetic confinement fusion research
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Nuclear Materials and Properties
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Laser-induced spectroscopy and plasma
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Laser-Matter Interactions and Applications
- Particle Accelerators and Free-Electron Lasers
- Ion-surface interactions and analysis
- Advanced X-ray Imaging Techniques
KTH Royal Institute of Technology
2021-2025
Czech Academy of Sciences, Institute of Physics
2019-2021
Technische Universität Berlin
2020
The experiments carried out in hydrogen at the TOMAS facility show possibility of controlling plasma parameters such as temperature and electron density a combined cyclotron resonance radio frequency (ECR+RF) discharge. A maximum up to ≈6 × 1016 m−3 35 eV are observed ECR+RF propagation RF waves under weak magnetic field is analyzed. Depending on experimental conditions, radial distribution field, there can be several cases: only slow wave propagate, simultaneously fast or propagate....
Abstract An assessment of the tritium (T) inventory in plasma facing components (PFC) during JET T and deuterium-tritium (DT) operations is presented based on most comprehensive ex situ fuel retention data set PFCs from 2015-2016 ILW3 operating period presented. The global 4.19 × 10 23 D atoms, 0.19% injected fuel. inner divertor remains region highest (46.5%). at end calculated as 7.48 22 atoms informative for accountancy, clean-up efficacy waste liability assessments. accumulation rate...
Abstract A sequence of fuel recovery methods was tested in JET, equipped with the ITER-like beryllium main chamber wall and tungsten divertor, to reduce plasma deuterium concentration less than 1% preparation for operation tritium. This also a key activity regard refining clean-up strategy be implemented at end 2nd DT campaign JET (DTE2) assess tools that are envisaged mitigate tritium inventory build-up ITER. The began 4 days baking 320 °C, followed by further which Ion Cyclotron Wall...
To improve the plasma performance and control density quality during flat top phase, wall conditioning techniques are used in large fusion devices like W7-X JT60-SA. study of electron cyclotron conditioning, numerous experiments were performed on TOroidally MAgnetized System, which is operated by LPP-ERM/KMS at FZ-Jülich. It a facility designed to production, plasma–surface interactions. The produced resonance heating plasmas characterized various conditions temperature measurements using...
Abstract Efficient Electron Cyclotron Resonance Heating (ECRH) breakdown and pre-ionization can be achieved with fundamental X-mode, while higher harmonics introduce excessive stray radiation. Fundamental heating however is characterized by a low cut-off density, introducing additional power absorption mechanisms in the plasma. A good knowledge of these necessary to use X-mode as an efficient method. Numerous experiments were performed on TOroidally MAgnetized System (TOMAS) study deposition...
Abstract This paper presents an overview of the TOMAS plasma diagnostics. The Langmuir probe method is employed to measure electron temperature, density and floating potential distributions.Two triple probes (horizontal vertical distributions) a single distribution) are used. measured parameters by compared. ion neutral atom flux energy distribution respectively characterized with Residual Field Energy Analyzer Time-of-Flight Neutral Particle Analyzer. To determine elemental/charge content...
In the TOMAS device, a triple Langmuir probe is used to measure electron temperature and density. The accuracy of this measurement depends on correct determination effective collecting area probe, which complex plasma transport processes. can be calibrated by cyclotron resonance heating experiments using cut-off density ordinary wave (O-wave). This threshold only frequency injected wave, occurrence phenomenon clearly visible in evolution. value consequently known at point calibrate...
Abstract The morphology of beryllium coatings on the Inconel inner wall cladding tiles after JET-ILW campaigns was determined. focus on: (i) fuel retention and its share in overall inventory; (ii) change layer structure composition. study is motivated view planned D-T operation JET. Four were examined: initial not exposed; one exposed to two (ILW1-2) facing plasma during ILW1–3. As determined with ion beam microscopy methods, Be (9.0 μ m thick) contained up 4–5 at.% impurities, mainly H, O,...
Abstract Aerosol nanoparticle injectors are fundamentally important for experiments where container-free sample handling is needed to study isolated nanoparticles. The injector consists of a nebuliser, differential pumping unit, and an aerodynamic lens create deliver focused particle beam the interaction point inside vacuum chamber. tightest focus close tip. density focusing carrier gas high at this point. We show here how interacts with near infrared laser pulse (800 nm wavelength, 120 fs...
Abstract This work was carried out to identify sources of errors, uncertainties and discrepancies in studies fuel retention wall components from the JET tokamak using methods based on thermal desorption. Parallel aims were establish good practices measurements unify procedures data handling. A comprehensive program designed for deuterium quantification comprised definition preparation two types materials (samples limiter Be tiles deuterium-containing targets produced laboratory by...
The THz-field-driven streak camera has proven to be a powerful diagnostic-technique that enables the shot-to-shot characterization of duration and arrival time jitter free electron laser (FEL) pulses. Here we investigate performance three computational approaches capable determine FEL pulses with complex temporal structures from single-shot measurements up simultaneously recorded spectra. We use numerically simulated in order validate accuracy pulse length retrieval average as well mode....
A characterization of plasma parameters and neutral particle energies fluxes has been performed for radio frequency microwave discharges in the Toroidal Magnetized System (TOMAS). movable triple Langmuir probe was used to study electron densities temperatures, a time-of-flight analyzer measure energy particles, as function total injected power antenna generate plasma. The experimental results can provide information on behavior particles at low wall conditioning plasmas.
We report on a surprisingly efficient acceleration of ambient gas ions in the presence laser-irradiated nanoparticle. Near-infrared laser pulses with an intensity $2\ifmmode\times\else\texttimes\fi{}{10}^{15}\phantom{\rule{0.28em}{0ex}}\mathrm{W}\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$ are used to irradiate single CsCl nanoparticle surrounded by helium density around ${10}^{15}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$. In this interaction...
Plasma edge cooling, ion cyclotron wall conditioning and disruption mitigation techniques involve massive gas injection (by puffs or pellets) to the torus. A certain fraction remains in plasma-facing components (PFC) due co-deposition implantation. An uncontrolled release/desorption of such retained species affects stability plasma operation. The aim this work was determine lateral depth distribution noble (3He, 4He, Ne, Ar), seeded (N2, Ar) tracer gases (15N, 18O) PFC retrieved from JET...
Polycrystalline (PC) and single crystal (SC) molybdenum mirrors were irradiated with 98Mo+, 1H+, 4He+, 11B+ 184W+. Energies chosen to impact the optically active region (up 30 nm deep) of Mo mirrors. Some surfaces coated by magnetron sputtering either B or W films 4–65 thick. The overall objective was simulate neutron-induced damage transmutation (H, He), H, He, B, on optical performance test mirrors, fuel retention. In parallel, a set PC 1.6 MeV 98Mo3+ 2 dpa 20 installed in JET tokamak for...
The paper provides a concise overview of ion beam analysis methods and procedures in studies materials exposed to fusion plasmas controlled devices with magnetic confinement. An impact erosion–deposition processes on the morphology wall is presented. In particular, results for deuterium analyses are discussed. Underlying physics, advantages limitations addressed. role diagnostics material migration fuel retention explained. A brief note research handling radioactive beryllium-contaminated also given.