E. Rachlew
A5018334950- Magnetic confinement fusion research
- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Fusion materials and technologies
- Mass Spectrometry Techniques and Applications
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Photochemistry and Electron Transfer Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy and Quantum Chemical Studies
- Nuclear reactor physics and engineering
- DNA and Nucleic Acid Chemistry
- Spectroscopy and Laser Applications
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Fluid Dynamics and Turbulent Flows
- Ion-surface interactions and analysis
- Atmospheric chemistry and aerosols
- High-Energy Particle Collisions Research
- Inorganic Fluorides and Related Compounds
Chalmers University of Technology
2021-2024
KTH Royal Institute of Technology
2009-2023
Royal Military Academy
2020
European Incoherent Scatter Scientific Association
2007-2012
AlbaNova
2004-2012
Culham Science Centre
2010
Swedish Research Council
2003
University of Oslo
1997
Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external $n=1$ perturbation field generated by four error correction coils located far from plasma. During application of ELM frequency increased factor 4 and amplitude ${\mathrm{D}}_{\ensuremath{\alpha}}$ signal decreased. The energy loss per normalized to total stored energy, $\ensuremath{\Delta}W/W$, dropped values below 2%. Transport analyses shows no or only moderate (up 20%) degradation confinement...
Abstract The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with ITER-like Be/W wall. development started pure Deuterium refinement of current, and toroidal magnetic field choices succeeded solving heat load challenges arising 37 MW injected power ITER like environment, keeping radiation edge core controlled, avoiding MHD instabilities reaching high neutron rates. have re-run Tritium...
Simultaneous current ramping and application of lower hybrid heating drive (LHCD) have produced a region with zero density within measurement errors in the core ( r/a< or =0.2) JET tokamak optimized shear discharges. The reduction is consistent simple physical explanation numerical simulations radial diffusion including effects LHCD. However, clamped at zero, indicating existence mechanism which prevents it from becoming negative.
A new technique has been developed to produce plasmas with improved confinement relative the H98,y2 scaling law (ITER Physics Expert Groups on Confinement and Transport Modelling Database ITER Basics Editors EDA 1999 Nucl. Fusion 39 2175) JET tokamak. In mid-size tokamaks ASDEX upgrade DIII-D heating during current formation is used a flat q-profile minimum close 1. On this leads q-profiles similar q but opposite other not an state. By changing method utilizing faster ramp temporary higher...
The current situation and possible future developments for nuclear power—including fission fusion processes—is presented. power continues to be an essential part of the low-carbon electricity generation in world decades come. There are breakthrough possibilities development new reactors where life-time waste can reduced some hundreds years instead present time-scales hundred thousand years. Research on fourth is needed realisation this development. For fast reactors, a substantial research...
Abstract The work describes the pedestal structure, transport and stability in an effective mass ( A eff ) scan from pure deuterium to tritium plasmas using a type I ELMy H-mode dataset which key parameters that affect behaviour (normalized pressure, ratio of separatrix density density, ion Larmor radius, collisionality rotation) are kept as constant possible. Experimental results show significant increase at top with increasing , modest reduction temperature pressure. variations heights...
Near edge x-ray absorption fine structure spectra have been measured and interpreted by means of density functional theory for five different azabenzenes (pyridine, pyridazine, pyrimidine, pyrazine, s-triazine) in the gas phase. The experimental theoretical at N 1s C edges show a strong resonance assigned to transition electron respective or atoms lowest unoccupied molecular orbital with π* symmetry. As opposed edge, this is split due environments core hole atom molecule. shift atomic...
A detailed experimental and theoretical investigation of the dynamics leading to fragmentation doubly ionized molecular thiophene is presented. Dissociation double-ionized molecules was induced by S $2p$ core photoionization ionic fragments were detected in coincidence with Auger electrons from core-hole decay. Rich observed electron-ion-ion maps exhibiting ring breaks accompanied hydrogen losses and/or migration. The probabilities various dissociation channels seen be very sensitive...
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...
In JET, advanced tokamak research mainly focuses on plasmas with internal transport barriers (ITBs) that are strongly influenced by the current density profile. A previously developed optimized shear regime low magnetic in plasma centre has been extended to deeply negative configurations. High fusion performance wide ITBs obtained transiently central configuration: HIPB98(y,2) ∼ 1.9, βN = 2.4 at Ip 2.5 MA. At somewhat reduced performance, electron and ion have sustained full drive operation...
The operational domain for active control of type-I edge localized modes (ELMs) with an n = 1 external magnetic perturbation field induced by the ex-vessel error correction coils on JET has been developed towards more ITER-relevant regimes high plasma triangularity, up to 0.45, normalized beta, 3.0, current 2.0 MA and q95 varied between 3.0 4.8. results ELM mitigation in triangularity plasmas show that frequency ELMs increased a factor 4 during application fields, while energy loss per ELM,...
Advanced scenario plasmas must often be run at low densities and high power, leading to hot edge temperatures consequent power handling issues plasma - surface interaction zones. Experiments ...
We report the identification of a localized current structure inside JET plasma. It is field-aligned closed helical ribbon, carrying in same direction as background profile (cocurrent), rotating toroidally with ion velocity (corotating). appears to be located at flat spot plasma pressure profile, top pedestal. The spontaneously low density, high rotation plasmas, and can last up 1.4 s, time comparable local resistive time. considerably delays appearance first edge mode.Received 23 November...
The poloidal distribution of the halo current density on top dump plate in JET can now be measured thanks to a new set Rogowskii coils. These are first measurements able offer an insight width interaction with wall. Therefore they both validation assumption made for disruption design criteria and one additional point extrapolation expected width, hence (and related local electro-mechanical loads in-vessel components) ITER. During upward events, is consistent total current. footprint extends...
Several improvements to the MAST plant and diagnostics have facilitated new studies advancing physics basis for ITER DEMO, as well future spherical tokamaks (STs). Using increased heating capabilities P NBI ⩽ 3.8 MW H-mode at I p = 1.2 MA was accessed showing that energy confinement on scales more weakly with strongly B t than in IPB98( y , 2) scaling. Measurements of fuel retention shallow pellets extrapolate an particle throughput 70% its original designed total capacity. The anomalous...
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).
Beam-target reactions are responsible for a substantial fraction of the fusion power generated in D-T plasmas JET-ILW (Be/W-wall), with ion temperatures 10-12keV and large neutral-beam injection (NBI) power.It is known that injecting D beam ions energies ~100-150keV T-rich has larger potential beam-target than 50:50 D:T plasmas, but such scenario was never developed past experiments performed JET-C (Carbon-wall) TFTR 90's.On top intrinsic advantages using beams neutron production,...
Scaling to larger tokamaks of high confinement plasmas with radiating edges, induced by impurities, is being studied through internationally collaborative experiments on JET. In campaigns till the end 2000, three different regimes have been explored. A small number limiter L-mode discharges seeded neon most closely repeated approach used TEXTOR-94, but collisionality and particle transport in JET impede central peaking density associated improved confinement. Divertor L-modes at intermediate...
Ion cyclotron resonance frequencies (ICRF) mode conversion has been developed for localized on-axis and off-axis bulk electron heating on the JET tokamak. The fast magnetosonic waves launched from low-field side ICRF antennas are mode-converted to short-wavelength high-field of 3He ion layer in D 4He plasmas subsequently damped electrons. resulting power deposition, measured using modulation, is narrow with a typical full-width at half-maximum ≈30 cm (i.e. about 30% minor radius) total...
Photofragmentation of thymine and 5-bromouracil into cation neutral fragments following the core ionization by soft x-rays using photoelectron-photoion-photoion coincidence technique has been studied. The fragment ion mass spectra were recorded in with C 1s photoelectron spectra. In case thymine, deuterated samples used to identify fragments. Deuteration or bromination allowed us study not only main fragmentation channels these pyrimidine bases, but also investigate if replacement an...
Discharges in the thin shell reversed field pinch (RFP) device EXTRAP T2R without active feedback control are characterized by growth of non-resonant m = 1 unstable resistive wall modes (RWMs) agreement with linear MHD theory. Resonant tearing (TMs) exhibit initially fast rotation and associated perturbed radial fields at small, but eventually TMs wall-lock give rise to a growing field. The increase due RWMs wall-locked is correlated an toroidal loop voltage, which leads discharge...
A key issue for steady-state tokamak operation is to determine the edge conditions that are compatible both with good core confinement and power handling plasma exhaust capabilities of facing components (PFCs) divertor systems. quantitative response this open question will provide a robust scientific basis reliable extrapolation present regimes an ITER scenario. In context, JET programme addressing focused on development non-inductive, high plasmas constraints imposed by PFCs. new beryllium...