B. Lomanowski
A5044973546- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Building Energy and Comfort Optimization
- Atomic and Molecular Physics
- Urban Heat Island Mitigation
- Nuclear Materials and Properties
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- High-Energy Particle Collisions Research
- Solar Thermal and Photovoltaic Systems
- Digital Radiography and Breast Imaging
- Wind and Air Flow Studies
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
Oak Ridge National Laboratory
2019-2024
Royal Military Academy
2020
Aalto University
2016-2019
Durham University
2014-2017
University Foundation
2016
Natural Resources Canada
2011
University of Waterloo
2007
Abstract Ion temperatures of over 100 million degrees Kelvin (8.6 keV) have been produced in the ST40 compact high-field spherical tokamak (ST). excess 5 keV not previously reached any ST and only obtained much larger devices with substantially more plasma heating power. The corresponding fusion triple product is calculated to be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>n</mml:mi> <mml:mi>i</mml:mi> <mml:mn>0</mml:mn>...
Abstract As part the DTE2 campaign in JET tokamak, we conducted a parameter scan T and D-T complementing existing pulses H D. For different main ion masses, type-I ELMy H-modes at fixed plasma current magnetic field can have pedestal pressure varying by factor of 4 total changing from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo>...
Abstract ST40 is a compact, high-field ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mi mathvariant="normal">T</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> <mml:mtext>⩽</mml:mtext> <mml:mn>2.1</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mtext>T</mml:mtext> </mml:math> ) spherical tokamak (ST) with mission to expand the physics and technology basis for ST route commercial fusion. The research programme covers...
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
Abstract The dimensionless isotope mass scaling experiment between pure Deuterium and Tritium plasmas with matched <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:math> , <mml:mi>ν</mml:mi> β n q <mml:msub> <mml:mi>T</mml:mi> <mml:mi>e</mml:mi> </mml:msub> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mi>i</mml:mi> has been achieved in JET L-mode dominant electron heating (NBI+ohmic) conditions....
Abstract Building on prior analysis of ASDEX Upgrade (AUG) experiments (Henderson et al 2023 Nucl. Fusion 63 086024), this study compares simple analytical formula predictions for divertor detachment onset and reattachment timescales in JET experiments. Detachment primarily scales with neutral pressure, impurity concentration, power directed to the targets, machine size, integral perpendicular decay length. experiments, focusing seeding mixtures Ne Ar, align predictions. Radiation...
Abstract Spherical tokamaks (STs) present unique challenges and opportunities in the area of particle power exhaust, intensified due to their more compact sizes.&#xD;Substantial efforts are underway STs determine limits dissipative operational regimes advanced divertor solutions, including at MAST-U which provides access Super-X configuration.&#xD;Power balance, upper/lower asymmetries have been studied using SOLPS-ITER simulations divertor. &#xD;A set with experimentally...
Abstract A parametrised spectral line profile model is formulated to investigate the diagnostic scope for recovering plasma parameters from hydrogenic Balmer and Paschen series spectroscopy in context of JET-ILW divertor plasmas. The separate treatment Zeeman Stark contributions tested against PPP-B code which accounts their combined influence on shape. proposed simplified does not fully reproduce Stark–Zeeman features α β transitions, but good agreement observed width wing profiles,...
In DT plasmas, toroidal Alfvén eigenmodes (TAEs) can be made unstable by the alpha particles resulting from fusion reactions, and may induce a significant redistribution of fast ions. Recent experiments have been conducted in JET deuterium plasmas order to prepare scenarios aimed at observing alpha-driven TAEs future campaign. Discharges low density, large core temperatures associated with presence internal transport barriers characterised good energetic ion confinement performed. ICRH has...
The electron temperature and density pedestals tend to vary in their relative radial positions, as observed DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) ASDEX Upgrade (Dunne 2017 Plasma Control. Fusion 59 14017). This so-called shift has an impact on the pedestal magnetohydrodynamic (MHD) stability hence height (Osborne 2015 Nucl. 55 063018). present work studies effect of JET ITER-like wall (JET-ILW) baseline low triangularity (δ) unseeded plasmas, similar JET-C discharges. As...
Abstract A reduction of the pedestal pressure with increasing separatrix density over ( n e sep / ped ) has been observed in JET. The physics behind this correlation is investigated. due to two distinct mechanisms. increase till ≈0.4 shifts radially outwards, decreasing peeling-balloning stability and reducing height. effect position saturates above ≈ 0.4. For higher values, ascribed increased turbulent transport and, likely, resistive MHD effects. reduces ∇ /n , η transport. This gradient...
Recent measurements of the Lyβ/Dα ratio in JET ITER-like wall (ILW) divertor show comparatively more pronounced Lyβ reabsorption relative to previous results with carbon (JET-C). At outer horizontal target ion current rollover point a rate 60% is measured, increasing 80% detachment, implying Lyα 90-98%. The radially resolved are used constrain Lyman opacity corrections atomic coefficients using population escape factor technique order capture local changes excited state structure high...
Abstract JET-ILW type I ELMy H-modes at 2.5 MA/2.8 T with constant NBI heating (23 MW) and gas fuelling rate were performed, utilising edge localised mode (ELM) pacing by vertical kicks plasma shaping (triangularity, δ ) as tools to disentangle the effects of ELMs, inter-ELM transport stability on pedestal particle balance. In agreement previous studies, confinement improves increasing , mostly due a significant increase in density while ELM frequency ( <?CDATA $f_{\mathrm{ELM}}$?> <mml:math...
A suite of multi-channel resistive bolometers has been implemented to measure the total radiation from Mega Amp Spherical Tokamak Upgrade plasmas, with cameras covering core plasma and lower divertor chamber. Data are digitized processed using novel field-programmable gate array-based electronics, offering improved compactness new operational capabilities. synthetic diagnostic developed explore quality 2D reconstructions available system quantify uncertainty on quantities such as radiated...
Three dimensionless scans in the normalized Larmor radius ρ*, collisionality ν* and plasma pressure β have been performed JET with ITER-like wall (JET-ILW).
Considering reflections from metallic wall surfaces in generation of tomographic reconstructions the tangentially viewing, visible-range spectroscopic divertor cameras JET has been observed to yield enhanced spatial accuracy and significant reduction emission artifacts experimentally resolved 2D line distributions. Neglection tomography process was found lead overestimation near by up a factor 4, as well formation bright between main regions surfaces, comprising locally 50% emission....
Abstract Changes in global and edge plasma parameters ( H 98(y,2) , dimensionless collisionality ν * core density peaking, separatrix n e,sep ) with variations the D 2 fueling rate divertor configuration are unified into a single trend when mapped to ⟨ T e,ot ⟩, spatially averaged spectroscopically derived outer target electron temperature. Dedicated JET ITER-like wall (JET-ILW) experiments combination an extended JET-ILW database of unseeded low-triangularity H-mode plasmas spanning wide...
Abstract The Mega Ampère Spherical Tokamak (MAST) programme is strongly focused on addressing key physics issues in preparation for operation of ITER as well providing solutions DEMO design choices. In this regard, MAST has provided results understanding and optimizing H-mode confinement, operating with smaller edge localized modes (ELMs), predicting handling plasma exhaust tailoring auxiliary current drive. all cases, the high-resolution diagnostic capability complemented by sophisticated...
Modeling and experimental investigation of the distribution seeded impurities their influence on divertor detachment in all-metal tokamaks is critical for developing reactor-scale exhaust scenarios. In this work, degree operating space Ne N impurity induced JET with ITER-like wall (JET-ILW) L-mode discharges shown to be regulated by combination i) local radiative dissipation low-field side divertor; ii) incursion ionization front towards X-point increased seeding. Using a quantitative...
The contributions of deuterium molecular emission to the total radiation was assessed in DIII-D ohmically-confined plasmas high-recycling divertor conditions. Radial profiles Ly-α line intensity across low-field side leg were obtained with recently installed Survey Poor Resolution, Extended Spectrometer [1]. A high-resolution spectrometer used measure poloidal Balmer-α and Fulcher-α band visible wavelength range. scrape-off layer plasma neutral distributions simulated using edge fluid...