Lı̅ga Avotiņa
A5061205763- Fusion materials and technologies
- Magnetic confinement fusion research
- Nuclear Materials and Properties
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Metal and Thin Film Mechanics
- Fuel Cells and Related Materials
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Advanced Battery Technologies Research
- Chemical Synthesis and Characterization
- Nuclear materials and radiation effects
- Photochromic and Fluorescence Chemistry
- Ion-surface interactions and analysis
- Advanced ceramic materials synthesis
- Dyeing and Modifying Textile Fibers
- Advanced Materials Characterization Techniques
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Membrane-based Ion Separation Techniques
- Hydrogen Storage and Materials
- Radioactive element chemistry and processing
- ZnO doping and properties
- Thermal properties of materials
University of Latvia
2014-2024
Riga Stradiņš University
2023
Riga Technical University
2023
Liga Contra el Cancer
2022
Royal Military Academy
2020
University of Bucharest
2017
National Institute for Laser Plasma and Radiation Physics
2016
Abstract The JET 2019–2020 scientific and technological programme exploited the results of years concerted engineering work, including ITER-like wall (ILW: Be W divertor) installed in 2010, improved diagnostic capabilities now fully available, a major neutral beam injection upgrade providing record power 2019–2020, tested technical procedural preparation for safe operation with tritium. Research along three complementary axes yielded wealth new results. Firstly, plasma delivered scenarios...
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...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
Abstract For the past several years, JET scientific programme (Pamela et al 2007 Fusion Eng. Des . 82 590) has been engaged in a multi-campaign effort, including experiments D, H and T, leading up to 2020 first with 50%/50% D–T mixtures since 1997 ever plasmas ITER mix of plasma-facing component materials. this purpose, concerted physics technology was launched view prepare campaign (DTE2). This paper addresses key elements developed by directly contributing preparation. intense preparation...
The objective of thermonuclear fusion consists producing electricity from the coalescence light nuclei in high temperature plasmas. most promising route to envisages confinement such plasmas with magnetic fields, whose studied configuration is tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one main potential showstoppers on a commercial reactor. In this work we report how, deploying innovative analysis methods thousands JET experiments covering isotopic...
One way to improve characteristics of oxide coatings prepared by plasma electrolytic oxidation (PEO) method in suspensions lies variation solid particle properties. In this study, the effect crystallinity on different physicochemical properties and bioactivity Ti Ti6Al4V substrates was studied, repeatability resulting assessed depending selected substrates. PEO performed direct current mode at a voltage 350 V electrolytes containing 0.1 M KH2PO4 100 g.L-1 stoichiometric crystalline...
The near-room temperature thermoelectric properties of self-assembling ZnO nanowire networks before and after encapsulation in nonconductive polymers are studied. were synthesized via a two-step fabrication technique involving the deposition metallic Zn by thermal evaporation, followed oxidation. Synthesized encapsulated polyvinyl alcohol (PVA) or commercially available epoxy adhesive. Comparison electrical resistance Seebeck coefficient showed significant increase network's conductivity...
Understanding photochromicity is essential for developing new means of modulating the optical properties and response materials. Here, we report on synthesis exciting photochromic behavior Nb5+ doped TiO2 nanoparticle colloids (NCs). We find that, in hole scavenging media, doping significantly improves time nanoparticles. In infrared regime, Nb-doped NCs exhibit 1 order magnitude faster photoresponse kinetics than pristine TiO2. Enhanced observed visible light regime as well. The...
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...
Proton exchange membranes (PEM), which have been commonly used in fuel cells raised interest for the application harsh environments involving ionizing radiation. Therefore, radiation stability and ability to sustain their functionality under environment are of great interest. Within this study, electron beam irradiation dose range from 50 500kGy was evaluate effects on physico-chemical mechanical properties two types PEM: commercial Nafion®117 sulfonated poly(ether-ether-ketone) (SPEEK) with...
Abstract Physical vapor deposition (PVD) of metallic thin films is used extensively in the fabrication semiconductor technology devices - use as lately for them have grown. Tungsten (W) a low resistivity, refractory metal, that often deposited by PVD methods gate contact to and due work function high thermal stability, W can be field emitters microelectronics [1-3]. In order monitor quality synthesized magnetron sputtering method, it necessary develop methodology suitable analysis these...
Abstract In this study, a tritium enrichment system in the water phase has been developed based on combination of proton exchange membrane (PEM) electrolysis cell and fuel cell. As PEM, Nafion TM laboratory-synthesized sulfonated poly(ether ether ketone) membranes modified with an additional graphene layer order to enhance separation factor were used. Both differences kinetics hydrogen evolution reaction transport through different isotopes are driving factors expected affect isotopes. The...
Tritium depth profile and its temperature programmed desorption rate were determined for selected samples cut out of beryllium tiles removed from the Joint European Torus vacuum vessel during 2012 shut down. A dissolution method under controlled conditions was used to determine tritium in samples, whereas experiments performed assess release pattern. Released measured using a proportional gas flow detector. Prior experiments, plasma-facing surfaces studied by scanning electron microscopy...
This study examines the electrical properties and layer quality of field emission microtriodes that have planar electrode geometry are based on tungsten (W) silicon dioxide (SiO2). Two types were analyzed: one with a multi-tip cathode fabricated using photolithography (PL) other single-tip focused ion beam (FIB). Atomic force microscopy (AFM) analysis revealed surface roughness W in order several nanometers (Ra = 3.8 ± 0.5 nm). The work function values Si substrate, SiO2 layer, estimated...
The four-cyclic condensed aromatic ketone 7H-benz[de]anthracene-7-one and its derivatives belong to the class of important anthraquinoid dyes, including laser luminescent dyes. Current work is devoted synthesis 3-cyanobenzanthrone evaluation being a useful precursor for obtaining new 3-substituted with heterocyclic moieties, handful which have been synthesized up now. photophysical properties prepared compounds are investigated. pronounced fluorescence fluorescent "turn-off" probes acidic...
The ITER-Like-Wall project has been carried out at the Joint European Torus (JET) to test plasma facing materials relevant ITER. Materials being tested include both bulk metals (Be and W) coatings. Tritium accumulation mechanisms release properties depend on wall components, their location in vacuum vessel, conditions of exposure material itself. In this study, beryllium limiter tiles, plasma-facing coated Inconel components from main chamber, tungsten carbon fibre composite divertor tiles...
An interesting development of biotechnology has linked microbial cell immobilisation with nanoparticles. The main task our research was to reveal the possible influences differently electrically charged diamond nanoparticles upon physiological characteristics yeast Saccharomyces cerevisiae. It revealed that adverse impact these can manifest not only against prokaryotes, but also eukaryotic cells. However, obtained results indicate it is reduce and, most likely, completely eliminate dangerous...
ITER-Like-Wall (ILW) project has been carried out at Joint European Torus (JET) to test plasma facing materials relevant International Thermonuclear Experimental Reactor – ITER [1]. Limiters and an upper dump plate of the vacuum vessel are made bulk beryllium tiles, whereas for divertor tungsten tungsten-coated carbon fibre (CFC) composite tiles used. During shutdowns in ILW1 (2012), ILW2 (2014) ILW3 (2016), selected were removed from vessel. In this study, three positions analysed, analysis...